Net Zero Energy Building: Predicted and Unintended Consequences 0815367791, 9780815367796

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Net Zero Energy Building

What do we mean by net zero energy? Zero operating energy? Zero energy costs? Zero emissions? There is no one answer: approaches to net zero building vary widely across the globe and are influenced by different environmental and cultural contexts. Net Zero Energy Building: Predicted and Unintended Consequences presents a comprehensive overview of variations in “net zero” building practices. Drawing on examples from countries such as the United States, United Kingdom, Germany, Japan, Hong Kong, and China, Ming Hu examines diverse approaches to net zero and reveals their intended and unintended consequences. Existing approaches often focus on operating energy: how to make buildings more efficient by reducing the energy consumed by climate control, lighting, and appliances. Hu goes beyond this by analyzing overall energy consumption and environmental impact across the entire life cycle of a building—ranging from the manufacture of building materials to transportation, renovation, and demolition. Is net zero building still achievable once we look at these factors? With clear implications for future practice, this is key reading for professionals in building design, architecture, and construction, as well as students on sustainable and green architecture courses. Ming Hu is an Assistant Professor at the School of Architecture, Planning and Preservation, University of Maryland, USA. She teaches technology courses which focus on the integration of architectural design with structural, materials, and building performance assessment. She is an architectural practitioner, educator, and researcher with expertise in high-performance building design, life cycle assessment, building performance measurement, and benchmarking. She has more than 14 years’ experience of working on international high-profile projects in firms including HOK’s Washington, DC office. Her background includes training in the architectural discipline and years of practice across disciplines, which gives her a unique perspective and ability to weave these fields together in her research.

“Ming Hu has not only given us the history of net-zero buildings and a detailed analysis of their design, but has taken net zero to the next logical level, demanding ‘zero impact’ building.” Dr. William W. Braham, FAIA, University of Pennsylvania “The need for increasingly aggressive energy efficiency goals parallels the rising need to curb greenhouse gas emissions. Carbon-neutrality has given way to net zero, a simple standard which Professor Ming Hu lucidly explains in its many achievable and some complex variations. This book will help policy makers pick an interpretation which is both effective and achievable; an essential accessory for this next phase of green design and building.” Ralph Bennett, FAIA, LEED AP (BD&C), Bennett Frank McCarthy Architects, Inc. “Net Zero Energy Building provides practitioners and policy makers the critical expertise and motivation needed for a net zero future in architecture and urbanism. Clear and illustrated chapters provide us with critical expertise on the definitions, the drivers, the quantification, and the innovations that will ensure zero impact through the full life cycle of the built environment. Ming Hu has created an irreplaceable reference for our shared future.” Vivian Loftness, FAIA, University Professor and Paul Mellon Chair in Architecture, Carnegie Mellon University

Net Zero Energy Building Predicted and Unintended Consequences

MING HU

First published 2019 by Routledge 2 Park Square, Milton Park, Abingdon, Oxon OX14 4RN and by Routledge 52 Vanderbilt Avenue, New York, NY 10017 Routledge is an imprint of the Taylor & Francis Group, an informa business  2019 Ming Hu The right of Ming Hu to be identified as author of this work has been asserted by her in accordance with sections 77 and 78 of the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this book may be reprinted or reproduced or utilized in any form or by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying and recording, or in any information storage or retrieval system, without permission in writing from the publishers. Trademark notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe. British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloging-in-Publication Data Names: Hu, Ming, 1975- author. Title: Net zero energy building : predicted and unintended consequences / Ming Hu. Description: Milton Park, Abingdon, Oxon ; New York, NY : Routledge, 2019. | Includes bibliographical references. Identifiers: LCCN 2018053250| ISBN 9780815367796 (hardback) | ISBN 9780815367802 (pbk.) | ISBN 9781351256520 (e-book) Subjects: LCSH: Sustainable construction. | Sustainable buildings. | Building—Social aspects. | Buildings—Environmental aspects. Classification: LCC TH880 .H795 2019 | DDC 720/.472—dc23 LC record available at https://lccn.loc.gov/2018053250 ISBN: 978-0-815-36779-6 (hbk) ISBN: 978-0-815-36780-2 (pbk) ISBN: 978-1-351-25652-0 (ebk) Typeset in Univers LT Std by Swales & Willis Ltd, Exeter, Devon, UK

Contents

List of illustrations vii Acknowledgments x Foreword xii Preface xv 1

The evolution of net zero energy building 1 Background and ecological origin: ecological economics 1 1930–1969: early solar house 2 1970–1989: first energy crisis and the emergence of net zero energy building 3 1990–2006: second energy crisis and the consensus on net zero energy building 7 2007–2010: financial crisis and rapid development of net zero energy building 9 2011–2017: financial recovery and blooming of net zero energy building 10 2018–beyond: net zero energy building 12 Conclusion 13

2

Principles of zero: metrics and assessment 17 Existing definitions of net zero buildings 17 The equation behind the definitions 30 Existing energy calculation methods 30 Measurement metrics 33 Conclusion 38

3

Predicted impact of net zero building 41 Trends and opportunities 41 Direct benefits of net zero building 42 Indirect benefits of net zero building 48 Cultural-social shift: impact on community 52 Conclusion 54

v

Contents

4

Unintended consequences of net zero building from a life cycle perspective 58 Net energy and its ecological economic origin 58 Unintended consequence one: environmental impact associated with embodied energy 62 Unintended consequence two: societal impact—more suburban sprawl and a green lifestyle? 66 Unintended consequence three: ecological degradation 69 Conclusion 70

5

Future drivers and economics 75 76 Environmental drivers 76 Regulatory drivers: mandates, regulations, and incentives 85 Human health drivers 87 Technology drivers: smart building 91 Economic drivers: the cost debate Conclusion 92

6

Advanced building materials and systems: smart green building 96 Nanotechnology 96 99 Phase-changing technologies 109 Responsive materials and systems Conclusion 113

7

Zero impact building: new framework based on life cycle assessment 117 Problems of existing net zero definitions 117 119 Life cycle energy assessment 120 Additional impact indicators Proposed definition of net zero impact building from a life cycle perspective 125 Proposed evaluation framework for net zero impact building 126 132 Scenario analysis Conclusion 133

8

Carbon-neutral development and net zero impact building: case studies 137 Carbon-neutral city and district 137 141 Three case studies Conclusion 151 Index 155

vi

Illustrations

Figures 1.1 1.2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 3.1 3.2 3.3 3.4 4.1 4.2 4.3 5.1 5.2 5.3 5.4 5.5

US Energy and Information Administration, International Energy Outlook 2017 Nearly zero energy building projects around the world: building type Linear history of net zero definition development West Berkeley Public Library West Berkeley Public Library section perspective West Berkeley Public Library plan West Berkeley Public Library interior Powerhouse Kjørbo Powerhouse Kjørbo Brabant house solar panels Brabant house Brabant house Hong Kong Zero Emissions Center Hong Kong Zero Emissions Center Hong Kong Zero Emissions Center Primary energy generation resources Comparison of CO2 emissions per capita Direct and indirect benefits/impacts of building green Building energy code adoption, 2016 Employment for design professionals, 2016 Employment for construction workers, 2016 Hierarchical organization in an ant nest Map of Lucca city Energy use (equivalent to a kg of oil per capita) Drivers for net zero practice Sekisui House Head Office in Osaka Edge exterior Central dashboards track building performance in Edge Intersection between smart building and green building

6 10 18 21 21 22 22 24 25 26 27 27 28 29 29 35 37 43 49 50 50 59 60 61 75 79 88 89 90

vii

List of illustrations

6.1 6.2 6.3 6.4

Yale University Sculpture Building and Gallery 98 Yale University Sculpture Building and Gallery 98 Types of PCMS 101 University of Washington, Molecular/Nano Engineering Building 103 6.5 GLASS®crystal details 104 6.6 GLASS®crystal details 104 6.7 Exterior façade of Centre Professionelle school in Fribourg, Switzerland 105 6.8 Interior view of Centre Professionelle school in Fribourg, Switzerland 105 6.9a PCM ceiling 106 6.9b PCM ceiling 106 6.10a PCM integrated in double-skin façade mode one 107 6.10b PCM integrated in double-skin façade mode two 108 6.10c PCM integrated in double-skin façade mode three 108 6.11 SageGlass 111 6.12 Piezoelectric tile 112 7.1 Life cycle assessment of building 120 7.2 Life cycle energy assessment 120 7.3 Suggested definition of framework 125 7.4 Suggested analysis framework 127 7.5 The methodological framework for an LCA 128 7.6 Tally analysis results 130 7.7 Life cycle water diagram 130 7.8 Life cycle health assessment diagram 131 8.1 A bird’s-eye view of Saltaire 138 8.2 Ebenezer Howard’s magnets diagram 140 8.3 Map of Malmö 141 8.4 Drainage channel with vegetation filter 143 8.5 Open water source 143 8.6 Map of HafenCity 145 8.7 Map of Tianjin Eco-city 148 8.8 Eco-cells and Eco-district 149 8.9 Low-carbon living lab 150

Tables 2.1 2.2 2.3 2.4 3.1 3.2

viii

Net zero building definitions Sample net zero building project information Brabant house cost compared to traditional house cost Comparison of metrics Direct and indirect benefits/impacts of building green Energy saving and water conservation of four sample net zero buildings

19 23 28 34 42 44

List of illustrations

3.3 4.1 4.2 5.1 5.2 5.3 7.1 8.1

Sample studies of productivity and green buildings Research and studies related to embodied energy and life cycle energy consumption of buildings Global initiatives to promote sustainable city development Selected national standards for energy-efficient new buildings Comparison of major building energy codes and regulations Green cost premium higher than conventional building Impact categories and measurement units Comparison of three case studies

47 64 69 77 81 91 123 152

ix

Acknowledgments

I owe a debt of gratitude to the many people who supported this book and helped me in a number of ways. First, I would like to thank my colleagues and students in the School of Architecture, Planning and Preservation at the University of Maryland (UMD). In particular, Architecture Program Director Brian Kelly, Interim Dean Donald Linebaugh, and Associate Dean Madlen Simon offered support in the form of funding, guidance, and research assistance. I also thank Professor Carl Bovil for his support and guidance from the outset of this book, as well as Ralph Bennett, professor emeritus, for his passion for sustainability and generous comments that contributed greatly to this book. Additionally, I truly appreciate the many suggestions contributed by colleagues and friends from UMD. I would also like to acknowledge Emma Weber for her involvement in the book, in helping to produce drawings and diagrams. Thank you to those who provided fact checking, took the time to answer my inquiries, offered interviews, and pointed me to resources, including Paul Torcellini at the National Renewable Energy Lab, William Braham at the University of Pennsylvania, Hofu Wu at California State Polytechnic University, and Vivian Loftness at Carnegie Mellon University. I am indebted to professor emeritus Norman Crowe from the University of Notre Dame for contributing the foreword. He generously offered his mentorship as chair while I wrote my Master of Architecture thesis, which connects the physical built environment with cultural values. I would also like to thank Dean Michael Lykoudis of the University of Notre Dame, who acted as my master’s thesis committee advisor and also provided support and guidance during my first teaching endeavors. Thank you to all the architects, engineers, consultants, and others who shared their knowledge and experience with me. This book would not be possible without their commitment to an energy-efficient future. I would also like to recognize the Rockefeller Foundation Bellagio Center Residency Program 2018–2019 for providing me with the ideal setting for a fellowship and an opportunity to exchange ideas with world-renowned scholars. I am also grateful to Jennifer Schmidt, the former acquisitions editor at Routledge/Taylor & Francis Group, who accepted my book proposal; Fran Ford, publisher at Routledge/Taylor & Francis Group, and Trudy Varcianna, editor at

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Acknowledgments

Routledge/Taylor & Francis Group, who shepherded the writing and publication phase. Thank you also to all the editors, the co-editor, and others who helped to bring this book to publication. In particular, I would like to acknowledge Janna Christie for her professional and excellent editing help and support. Finally, I would like to thank my dear family. To my parents, thank you for your unconditional support and love; to my brother and his family, thank you for being a great role model and supportive. I want to especially thank my husband, Kai Hu—my best friend and partner—for his love and support.

xi

Foreword

Ming Hu approaches energy use in the built environment from a comprehensive and rigorously scientific, historical, and technological perspective. In this book she has drawn together issues that have been regarded all too often as though they existed on their own, separate from one another in disregard for the reality of their complex interconnectivity. As she puts it in the text, “This book goes beyond current and well-known research on net zero building to critically examine overall energy consumption and carbon emissions reduction from a whole building life cycle perspective.” In addition, she reveals a host of both long-term and short-term forces that effect energy use in the built environment, including economic systems and theories, global political forces, availability and consumption of finite resources, and important hidden contributing factors such as embodied energy considerations and long-term human health and environmental impacts. In consideration of this accomplishment, I would like to step back for a moment to look at the context in which the implementation of such important practices as the net zero building concept take place. Primatologist and conservationist Jane Goodall once asked rhetorically, “How is it that the most intelligent animal to ever walk the surface of the earth is destroying its one and only home?” Of course, the answer has to do with changes caused by our technological prowess, economic expansion, and our mounting numbers, all occurring sufficiently slowly in historical time so that until relatively recently we failed to make the connections. But now we know that the task at hand must be to reverse the destruction of which Goodall spoke, and to develop an approach to the future that will sustain our presence on Earth without the continued destruction of the very thing that makes our lives and cultures possible. We live in a world that we began building for ourselves during the socalled Neolithic Revolution, beginning some 12,000 years ago following the last ice age—eventually leading to an interconnected world of towns and cities, buildings, industrial facilities, roads, streets, and highways, and extensive agricultural hinterlands. This world, often referred to as “the second world,” stands in contrast to the first world of nature in which it is built and upon which it is ultimately dependent. While we tend to think of the ancient world as having been sufficiently small in population and too weak in technological impact to have asserted any lasting damage on the natural world, there once existed a prevailing sense that the

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Foreword

second world must nonetheless be in harmony with nature. It was an overriding sensibility, a responsibility to the spirits that created nature. That belief expressed itself in various ways, sometimes successfully and sometimes not.i One particular practice by traditional societies that stands out among the rest was assuming that each element of their built world was in some way or other analogous to a comparable part of nature.ii The corner posts of a domicile, for instance, represented the four quadrants of creation, the smoke hole in the roof symbolized access to the wisdom of the sky spirits, while the hearthstone beneath it was a symbolic axis mundi, and the layout of the settlement itself replicated the order of the cosmos as they understood it to be. It was this sort of mind-set that acted to assert nature’s eternal presence. Of course, that practice eventually faded away as societies came to rely more and more on increasingly clever inventions—to the extent that nature eventually disappeared into the background where we find it today. But what we call Nature is still there, and it is as fully a part of our survival as it was for those traditional societies who worshiped it. Now it is incumbent upon us to make up for long-lapsed attention—to simultaneously address the damage already done and aim toward a future where our second world no longer threatens the first. The net zero concept is one such measure among many. While the net zero concept has its inherent deficiencies as Hu points out, it nonetheless seeks to effectively implement specific technological means and practices aimed at energy conservation, thereby serving as a construct to help us to realign our thinking about the relationship between our world and nature—perhaps not entirely unlike our ancient ancestor’s habit of considering each part of their built world as analogous to parts of the broader natural world. To grasp the significance of what Hu Ming has written, I would like to place Net Zero Building alongside an earlier book, Audubon House, published some 25 years ago.iii While Net Zero Building is much more, I see it, among other things, as effectively carrying forward a tradition begun by Audubon House of demonstrating thoughtful approaches to responsible building and urbanism through the device of the documented case study. Audubon House traced the renovation of just one building, an 1891 multi-story building in New York City, renovated to become the new headquarters for the environmentally focused National Audubon Society. The Audubon House renovation project itself broke ground in the breadth of its design for energy efficiency and for its consideration for protracted economic circumstances as well as human comfort and convenience. That book was perhaps the first to outline step-by-step decisions, practices, and costs in such a way as to illustrate the long-term economic advantages to owners of energy-conscious, or “green” buildings. It also presented positive environmental consequences of building within a dense urban setting as a means to reduce sprawl and promote a responsible approach to daily life. Significantly, Audubon House offered a range of useful paradigms as well as suggesting by inference a particular frame of mind for responsible building design and practices everywhere. Net Zero Building expands and refines this all-important frame of mind. Today’s building industry, like all else in a complex economy, is a creature of its environment. What must happen is that the building industry and the

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Foreword

infrastructure that supports it must become fully immersed in changing values that reflect an ethos of environmental responsibility, while at the same time making environmental responsibility economically desirable for building owners. As durable cultural artifacts, what societies build leaves behind concrete evidence of their values—of how they inhabited the Earth and exploited the resources the Earth provided them. Today’s buildings and all that they are a part of will speak volumes about us to future generations. We may hope that the evidence we leave behind will come to speak of our recognition of a commonly held sense of responsibility toward a sustainable future. Norman Crowe September 2018

Notes i For an historical accounting of environmental successes and failures from pre-historic times to the near-present, see Jared Diamond, Collapse: How Societies Choose to Fail or Succeed (Penguin Books, 2005). ii Detailed descriptions of the practice by traditional societies of ascribing characteristics of their built environment to comparable parts of the natural world may be found in the following: Christine Hugh-Jones, From the Milk River: Spatial and Temporal Processes in Northwest Amazonia (Cambridge University Press, 1979), 235; Peter J. Wilson, The Domestication of the Human Species (Yale University Press, 1988), xii; Norman Crowe, Nature and the Idea of a Man-made World (MIT Press, 1995), 30–31. iii National Audubon Society and Croxton Collaborative, Architects, Audubon House: Building the Environmentally Responsible, Energy-efficient Office (John Wiley & Sons, 1994).

xiv

Preface

Even though energy-efficient building has experienced continuous improvement since 1990—at an annual rate of approximately 1.5%1—certain improvements have been offset by a growing global wealth, which is reflected as larger spaces, bigger floor areas, an increased demand for energy services (individual electricity consumption increase due to multiple devices), and human comfort requirements. An expanding population accompanied by rapid purchasing power growth in emerging economies and developing countries (such as China and India) may cause a potential 50% increase in the overall global energy demand of buildings by 2050.2 Meanwhile, in order to limit the global temperature change to a rise of no more than 2–4 °C overall, an 80% reduction in world carbon emissions is required by 2050.3 The building sector offers the largest cost-effective greenhouse gas emissions reduction potential, with economic gains through the possible implementation of existing technologies, policies, and building designs. Consequently, close to 132 countries4 have already included building sector actions in their respective national strategic plans and increasingly search for ways to accelerate investment in net zero and net impact building design and construction. In order to achieve the 2 °C pathway, the building sector must reduce carbon (CO2) emissions by 40% by 2030 and energy consumption by 60% by 2020.5 This aggressive goal is nothing short of a dramatic transformation toward a completely zero-carbon built environment.6 A zero-carbon built environment requires net zero building, which currently is largely focused on operating energy. While significant effort has been devoted to increasing the energy efficiency of buildings in operation (i.e., reducing energy consumed by heating, lighting, ventilation, and appliances), the focus has not been extended to reducing embodied energy and induced energy in the building sector. There are several sustainable building rating systems, such as Leadership in Energy and Environmental Design (LEED), which have started to integrate certain requirements for embodied energy use, although the magnitude of the efforts is still limited. The research community generally agrees that, as the operating energy efficiency increases due to improvements in technology, the energy used and emissions created in other stages of a building’s life will become increasingly important. Therefore, it is essential to look beyond the current definition of net zero building and understand the various approaches and aspects advocated for achieving the net zero goal, such as zero operating energy, zero energy cost, zero emissions, and zero life cycle energy.

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Preface

This book goes beyond current and well-known research on net zero building to critically examine overall energy consumption and carbon emissions reduction from a whole building life cycle perspective. It presents a holistic overview of different net zero building approaches and their related consequences, both positive and unintended. This book also proposes an important conceptual framework to define net zero impact building, which represents a step above current net zero energy building. The proposed framework and case studies support a critical construct—reflective of the future of practice and academia—that deals with building materials, systems, energy consumption, the environmental impact, and human health within the whole building life cycle. Chapter 1 sets the stage for understanding the development and practice of the net zero concept in recent decades worldwide. Readers are provided with a general understanding of how diverse actors with miscellaneous motives have led to varying focuses and definitions in the development of net zero building. Chapter 2 directs the reader’s attention to the science underpinning the net zero concept. Four major net zero definitions are compared in a global context by examining exemplary buildings in several countries. The information gained from balancing operating energy consumption with embodied and induced energy consumption builds a foundation for further discussion in Chapters 3 and 4. Chapter 3 shifts the conversation, guiding readers through major positive influences of the energy efficiency movement. Additionally, this chapter outlines the potential market demand for achieving net zero worldwide and sets the tone to transition to a discussion of unintended consequences. Chapter 4 first provides an overview of the net energy definition and its development and evolvement in ecological economics to contrast its parallel version in the built environment. This chapter then dives deep into three major unintended consequences of the current net zero movement in the built environment. Chapter 5 takes a close global look at the five main drivers behind the predicted development trend: environmental, regulatory, human health, technology, and economic drivers. It also identifies the main technology drivers—advanced materials—that will be elaborated in the next chapter. Chapter 6 closely examines advanced building materials and assemblies used in net zero building and provides readers with a comprehensive understanding of the potential environmental and human health impacts of these advanced and energy-efficient materials and assemblies. This chapter bridges the thought gap between both energy and impact and society and economy. Chapter 7 synthesizes the preceding chapters. Problems in the existing definition of net zero building are first outlined. The chapter then introduces the important concept of zero impact building and, lastly, outlines and explains a framework and evaluation method that go beyond the existing net zero energy practice. Since an actual case is often ideal to advance the knowledge of net zero impact practices, Chapter 8 presents case studies of three built projects using a holistic life cycle framework. The similarities and uniqueness of each project are outlined, followed by a comparative summary drawing on the case studies.

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Preface

References 1

Intergovernmental Panel on Climate Change. “AR5 Climate Change 2014: Mitigation of Climate Change.” IPCC, 2014. Accessed January 2, 2019. www.ipcc.ch/report/ar5/wg3/ 2 International Energy Agency. Energy Technology Perspectives 2016: Towards Sustainable Urban Energy Systems. Accessed January 2, 2019. www.iea.org/ publications/freepublications/publication/EnergyTechnologyPerspectives2016_ ExecutiveSummary_EnglishVersion.pdf 3 Pachauri, Rajendra K., Myles R. Allen, Vicente R. Barros, John Broome, Wolfgang Cramer, Renate Christ, John A. Church et al. “AR5 Synthesis Report: Climate Change 2014.” IPCC, 2014. Accessed January 2, 2019. www.ipcc.ch/report/ar5/syr/ 4 Global Alliance for Buildings and Construction. Global Status Report 2017. Accessed January 2, 2019. www.worldgbc.org/sites/default/files/UNEP%20 188_GABC_en%20%28web%29.pdf 5 International Energy Agency. “Energy Efficiency Market Report 2015.” Accessed January 2, 2019. https://webstore.iea.org/energy-efficiency-marketreport-2015 6 Laski, Jonathan, and Victoria Burrows. From Thousands to Billions: Coordinated Action towards 100% Net Zero Carbon Buildings by 2050. World Green Building Council. Accessed January 2, 2019. www.worldgbc. org/sites/default/files/From%20Thousands%20To%20Billions%20 WorldGBC%20report_FINAL%20issue%20310517.compressed.pdf

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Chapter 1

The evolution of net zero energy building

Background and ecological origin: ecological economics The concept of “net energy” has its origin in, as well as a close relationship to, ecology. In 1920, English chemist Frederick Soddy first offered a new perspective on economics rooted in physics: the laws of thermodynamics. Soddy highlighted the importance of energy in social progress based on real wealth formation—as distinct from virtual wealth—and a debt accumulation process.1 He suggested a detailed accounting structure for energy use as a good alternative to the monetary system. The latter treated economics as a perpetual motion machine; however, as with any commodity, actual wealth flow should obey the laws of thermodynamics.2 Soddy argued that real wealth was derived from the use of energy to transform materials into physical goods and services.3 However, his theory was largely criticized and ignored in his time, due to his standing as a critic—not a scholar—of orthodox economics. The contempt was pervasive—in one review of his book Wealth, Virtual Wealth, and Debt, The Times Literary Supplement remarked: “it was sad to see a respected chemist ruin his reputation by writing on a subject about which he was quite ignorant . . . .”4 Consequently, the ignorance and criticism of Soddy’s theory contributed to a long-term lack of associated research development between 1920 and 1970 on the concept of energy flow, resulting in stalled progress in energy accounting for a lengthy period. During the above-mentioned gap, there was one notable development: the Technical Alliance, a professional group of architects, engineers, economists, and ecologists that was formed in 1919 before later disbanding in 1921. The group started the Energy Survey of North America with the aim of documenting the wastefulness of the entire society, marking the first attempt to quantify net energy.2 The ensuing silence during the following 50 years set the stage for the blossoming of new concepts and ideas that would emerge in the 1970s. In the 1970s, Romanian-American mathematician and economist Nicholas Georgescu-Roegen further developed ecological economics, or eco-economics, based on Soddy’s concepts. Eco-economics is a transdisciplinary and interdisciplinary field of research that includes ecology, economics, and physics. Georgescu-Roegen proposed the application of the entropy law in the field of economics, where he argued that all natural resource consumption is essentially

1

The evolution of net zero energy building

irreversible, which has a profound impact on the net energy flow or life cycle thinking of natural resources. He was the first economist of some standing to put forward theories on the premise that all of Earth’s mineral resources would eventually be exhausted at some point,5 and this concept of natural resource depletion eventually led to a movement of sustainable development. As he stated, “An unorthodox economist—such as myself—would say that what goes into the economic process represents valuable natural resources, and what is thrown out of it is valueless waste.”6 To some extent, we can consider Nicholas Georgescu-Roegen as the original gardener who planted the seeds of sustainable development in our society. Another important development in the 1970s was the publication of the article “Energy, ecology, and economics” and the book Environment, Power and Society by ecologist Howard Odum, who tackled economic issues using ecological theories based on energy fundamentals. His energy economics were based on the comprehension that energy is the foundation for all forms of life and is transformable. He stated that “the true value of energy to society is the net energy, which is that after the costs of getting and concentrating that energy are subtracted.”7 Odum’s view of studying ecology as a large and integrative ecosystem paved the way to an understanding of how different aspects of a whole ecosystem influence each other. In the latter part of his career, he developed a concept of energy in the 1990s, called Emergy. Odum explained that energy provides for real work and real wealth in any biophysical system, including the economy, in his 1996 publication, Environmental Accounting: Emergy and Environmental Decision Making.8 He stated: Understanding the economy requires that both money circulation and the pathways of real wealth be represented together but separately. Money is only paid to people and never to the environment for its work . . . Therefore, money and market values cannot be used to evaluate the real wealth from the environment. When the resources from the environment are abundant, little work is required from the economy.”8 Emergy has since attracted the attention of academic researchers and is being applied beyond just the natural ecosystem, to research in the building and construction industry.9, 10

1930–1969: early solar house Some of the first documented attempts toward energy-efficient buildings were merged as an effort to achieve net zero heating and cooling in solar houses, which originated around the 1930s. One of the earliest pioneer buildings was the 1939 MIT Solar House I, which introduced the use of a large solar thermal collector and water storage in houses.11 Additionally, the solar air collector and rock mass storage used in Bliss House have become two of the most applied solar technologies still in use today. In September 1936, the dean of the MIT School of Engineering, Vannevar Bush—a renowned American inventor, engineer,

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The evolution of net zero energy building

and early administrator of the Manhattan Projecti—began to pursue research in solar energy, and his idea of flat sun collectors impressed Boston-based philanthropist Godfrey L. Cabot. Cabot donated nearly $650,000 to MIT in 1938 and instructed that the fund be used specifically “in development of the art of converting the energy of the sun to the use of man by mechanical, electrical, or chemical means.” Consequently, the fund stimulated the formation of MIT’s Solar Energy Fund. Dr. Maria Telkes was the first hire by Vannevar Bush using the solar fund. Dr. Telkes’s expertise and knowledge as a physical chemist and biophysicist enabled her research on a thermoelectric device that could convert heat directly into electrical energy. This technology was very different from those used in other solar houses within the same MIT Solar Energy Research Project. During the 50 years that the Solar Energy Project lasted (1938–1988), a series of six experimental prototype solar houses were built.12 Among them, only Dover Sun House was built using Dr. Telkes’s technology instead of popular methods that used water as a heat storage material. Her device used sodium sulfate decahydrate (Glauber’s salt) as a storage material. The sun heat collector was composed of two layers of flat glass filled with air in between and a layer of black sheet metal completely covering the second layer of the glass panel, and these collectors and panels covered the entire south-facing façade of the house. The primary experimental and research objective of using the salt was to test the relative effectiveness of a chemical heat-of-fusion process, instead of conventional hot-water heat storage devices,13 with the hope of such technology eventually increasing the efficiency of solar energy conversion and making it more affordable and amenable when integrated into all types of building construction. During the daytime, hot air was circulated in the drums where the salts were stored. The salts contained crystals that were bound to water molecules; the crystals would melt at high temperatures while absorbing the heat. The heat would then be stored in a liquid form of the crystals. During the night, when the temperature dropped, the compound made of salt and water would recrystallize, releasing the heat.5 Interestingly, this technology could essentially be viewed as the predecessor of current phase-changing material technology (see Chapter 6 for more details).

1970–1989: first energy crisis and the emergence of net zero energy building The first wave of energy crises, in the 1970s, sparked an energy efficiency movement. On October 17, 1973, six Arab and non-Arab members of the Organization of the Petroleum Exporting Countries decided to raise the price of oil exports by 70%. On the same day, nine Arab oil-producing countries imposed an embargo on oil supplies to the United States and the Netherlands in response to the outbreak of the Yom Kippur War.14 The consequences of the two dramatic actions were devastating to the United States and the Netherlands, but also had a global impact. At that time, scientists and engineers from various fields, including physicists and chemists, started to pay more attention to energy consumption patterns. In particular, Dr. Arthur Rosenfeld,15 the “godfather of energy efficiency,” observed that the United States consumed about twice the energy per capita as its European

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The evolution of net zero energy building

counterparts, yet all had comparable standards of living.16 This proved two facts: first, energy could be conserved through user behavior—such as turning off lights in unoccupied rooms—and second, higher energy consumption did not translate into faster economic development or a higher living standard. He asserted that if Americans used energy at the same rate as Europeans or the Japanese, the United States could have begun exporting oil in 1973. Dr. Rosenfeld met up with colleagues from the Princeton Center for Energy and Environmental Studies and Professor Robert Socolow and Professor Sam Berman from Stanford University in 1974, resulting in an agreement that further studies on energy efficiency and conservation were needed. With financial support from the National Science Foundation and the Federal Energy Agency (later changed to the Department of Energy), the group held its first meeting at Princeton and invited experts in building, industry, transportation, and utilities. During the meeting, they discussed the causes of energy behavior in the United States as being due to cheap energy and abundant resources. This group of scientists, architects, and engineers produced the Princeton Study, which later became a book, Efficient Use of Energy (published in 1975). Dr. Rosenfeld later conducted numerous studies on energyefficient buildings and technologies, transforming from a professor of physics to a pioneer of building science and energy efficiency in the United States. In 1975, Dr. Rosenfeld and Professor Berman sponsored a summer study focus on energy-efficient buildings at the UC Berkeley School of Architecture, highlighting the practical application of energy conservation strategies and calculations to buildings. The expert group identified several important control points or attributors to a building’s energy efficiency that continue to be the center of all research and practice today: a building’s envelope and insulation, lighting and windows, Heating, ventilation, and air conditioning (HVAC) systems, and zone design. In 1979, President Jimmy Carter recognized the importance of energy conservation in relation to reducing dependency on Organization of the Petroleum Exporting Countries (OPEC) oil. He proposed an “energy bank”17 project with the aim of developing alternative energy resources, such as alternative gases and synthetic fuels. Around the same time, Dr. Rosenfeld and six researchers formed a think tank dedicated to energy conservation: the American Council for an Energy-Efficient Economy (ACEEE). The ACEEE focused primarily on the end user’s side of energy efficiency. Buildings, cities, and industries are all end users of primary energy. Since its inception, the ACEEE has conducted studies, held conferences, and become highly influential not only in the research community, but also among officials at the Department of Energy and the Environmental Protection Agency as well as members of congress. The ACEEE is still one of the most influential entities in today’s building energy conservation field, with many leading ideas and research—such as net zero and net positive building—having been first presented in ACEEE conferences. The first in-depth solar conversation study was funded by the Deputy Secretary of Energy under President Carter with about $1 million and conducted by the Solar Energy Research Institute (now the National Renewable Energy Laboratory) under the management of Dr. Henry Kelly and Carl Gawell, who invited Dr. Rosenfeld to lead the building study. However, the project was abruptly cut back to one third of the previous

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budget after the election of President Reagan. In late 1985, after OPEC collapsed, President Reagan and UK Prime Minister Margaret Thatcher proclaimed the energy crisis officially over, and the energy efficiency-related programs were not increased again until the Clinton administration took over. The influence of the first energy crisis on the building industry was profound. It ignited an energy upheaval that reshaped the entire world, touching people’s daily life and forcing a paradigm shift in the building and construction industry that is still not complete. Since 1973, a wide range of building energy efficiency methods have evolved: from the solar house, which focused on harvesting natural renewable energy from the sun, to a more holistic energy demand reduction effort. Between 1970 and 1990, the concept of net zero energy officially emerged as a viable design concept for an energy-saving method. Multiple organizations and programs were established with the goals of producing an energy-efficient design and decreasing energy consumption. For instance, the Weatherization Assistance Program of the US Department of Energy was established in 1976 with a focus on reducing energy costs for low-income households by increasing the energy efficiency of these homes.18 The first German Solar Forum was held in September 1977. Prior to this, the Building Services Research and Information Association was established in 1975 in the United Kingdom. One of the founding members, the British Research Establishment, later launched the Building Research Establishment Environmental Assessment Method (BREEAM), the world’s foremost sustainable building design assessment tool. The Energy Efficient Building Association was created in 1982 by a group of building professionals from the United States, Canada, and Sweden, and in 2008 was renamed the Energy and Environmental Building Alliance. The above are just some examples of leading forces in promoting the net zero concept worldwide. One of the very first net zero building experiments was the Danish zero energy house, conducted under the guidance of Professor Vagn Korsgaard from the Technical University of Denmark. This project took place in 1976–1977 and was situated on the outskirts of Copenhagen. The building was equipped with highly insulated construction materials, a 42 m2 flat-plate solar collector, and a seasonal water storage tank with a capacity of 30 m3.19 This project won the Passive House Pioneer Award in 2013, with Passive House founder Dr. Wolfgang Feist remarking: “The construction of this building was thus an important basis for later developments in Europe and around the world.”20 This project might have also been the first energy-efficient building experiment to use the term “net zero.” Some other common techniques used in today’s net zero building designs emerged during this period as well, such as super-insulated houses with highly efficient windows and lighting. In a 1988 paper, Dr. Rosenfeld introduced the concept of “super-insulated” houses. In the same year, the Passivhaus (Passive House) standard originated in Germany with very high requirements of insulation. According to Dr. Rosenfeld, “A standard insulated wall is R-11 and a ceiling is R-19 . . . a super-insulated House would have walls and ceilings rated up to R-30 and R-60, respectively.”21 Furthermore, he recommended using

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double glazing, instead of single glazing, which is now the industry standard practice. His recommendations have become the standard practice of current net zero building. Just as Soddy and Georgescu-Roegen stated, the efficiency of energy use and transformation could be used to measure real wealth formation. Also, as Rosenfeld pointed out, high energy consumption did not translate directly to higher living standards, and the oil embargo forced professionals in the building industry to recognize the absurdity of excessive energy consumption in the United States and begin thinking in terms of a building’s life cycle cost. Due to energy-conscious behavior following the 1973 oil crisis, since 1985 Americans have enjoyed a 35% rise in gross national product without increasing their energy consumption per capita GDP (see Figure 1.1). Rather than demanding more “source energy” from the planet, energy conservation through improved efficiency made more energy available for wide use. Meanwhile, through maximum cultivation of the “site energy,” it was proven that energy-efficient buildings—even net zero energy buildings—are possible. Energy is not only an engineering tool; it is also a design and lifestyle choice. Two important events that happened during the late 1980s have had longterm impacts on energy, economy, and environmental protection worldwide. First, the UC California Institute for Energy Efficiency (CIEE) was formed in 1989. It is supported through utility contributions of 1/5000th of its revenue, which would provide $5 million annually based on the projection at that time. The CIEE’s work is moving California closer to achieving its groundbreaking energy use and climate protection goals. The second event was the collapse of OPEC in 1986, due to a decision made by Saudi Arabia and other neighboring countries to increase their shares of the oil market by maintaining high crude oil production. The birth of the CIEE and collapse of OPEC and correlated activities marked a new era of efficient building design to come: the golden years of sustainable global development—especially energy-efficient building—during 1990–2006.

Figure 1.1  US Energy and Information Administration, International Energy Outlook 201722

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1990–2006: second energy crisis and the consensus on net zero energy building The second wave of energy crises was closely related to the First Gulf War. On August 2, 1990, Iraq invaded Kuwait. The war lasted nine months and resulted in a significant increase in oil and natural gas prices. Even though the price spike was less extreme and lasted for a shorter time than the previous energy crisis, collective efforts in the academic community and federal agencies worldwide produced promising efforts, proving the concept of net zero energy and completing several exemplary projects. When Clinton and Gore took office in 1992, the political environment for energy efficiency research and projects became friendlier. In 1996, the United States, Canada, and Mexico collaborated to produce the North American Energy Measurement and Verification Protocol, marking the first official attempt to provide consistent procedures for implementation by different stakeholders of energy projects to quantify energy conservation performance and energy savings. This protocol has been largely industry-driven and reflects a broad industry consensus. The document has become an important reference in the program to build energy efficiency in North America and has also been translated into other languages. However, in the 1990s, at a governmental and policy level, the US energy consumption portfolio changed very little, and energy demand continued to grow modestly while energy intensity declined modestly. During the same period, the Clinton administration’s energy policies were heavily influenced by concerns about the environmental impacts of energy consumption and production, including the impact of greenhouse gas emissions and climate change.23 Between 2000 and 2006, the American consensus around the definition of net zero energy started to emerge. In 2006, a National Renewable Energy Laboratory report indicated the lack of a common definition of “zero energy” and stated that “a zero-energy building can be defined in several ways, depending on the boundary and the metric.” Consequently, the terms net zero site energy (NESE), net zero source energy (NZSE), net zero energy cost (NZEC), and net zero energy emissions (NZEE) were proposed24 and became one of the common set of definitions used in the United States. In Northern and Western Europe, a couple of influential energy-efficient building movements had a profound impact on today’s net zero energy building practice. The first was the Passive House concept, which emerged in the late 1980s, integrating the super-insulated house and other valuable solar house theories and algorithms of design. The first “Passive House Kranichstein” was completed in 1991, in Darmstadt, Germany. In 1995, Dr. Feist developed the Passive House standard based on the construction and operation of the first house built in Darmstadt. The Passive House Institute was founded in 1996 and led by Dr. Feist, who began to promote the standard and set clear requirements.25 The first self-sufficient energy-autonomous house was designed and built by the Fraunhofer Institute for Solar Energy in Freiburg, Germany. This building had a high insulation value and employed the most advanced solar energy technologies at that time, allowing the house to be self-sustaining without the help of external energy sources.25 To overcome the seasonal mismatch between solar radiation

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and building energy demand, long-term storage (1500 kWh) based on hydrogen was introduced in combination with short-term electricity storage with lead-acid batteries (20 kWh).26 This house demonstrated that, with a highly insulated building envelope, it was possible to construct a house with almost no heat demand in a Central European climate. Besides proving technical feasibility, positive occupant feedback stimulated further research and development of net zero energy residential building in Germany. The second influential building standard was Minergie, a new standard created in Switzerland in 1994 for both new construction and renovation. Minergie was directed at low energy consumption buildings based on the ideas of Ruedi Kriesi and Heinz Uebersax.27 In 1997, Minergie-P was created with more rigorous requirements, which was the equivalent of the Passive House standard in Switzerland. In Central and Eastern Europe, nearly half of the existing housing stock was constructed between 1960 and 1990.28 During this time, housing was primarily built using a prefabricated method for large-scale multi-unit housing blocks; furthermore, there were no building energy codes to regulate the design and construction. Mass privatization in the 1990s resulted in a high owner-occupied unit rate, up to 90% of housing. This fast-paced privatization within two to three years led to an extremely insufficient regulatory framework for maintaining these buildings. Similar conditions also occurred in Southern Europe, following the collapse of the Soviet Union in 1991 and Yugoslavia in the early 1990s. Mass privatization without appropriate maintenance and upgrading plans in place resulted in the deterioration of many prefabricated houses over time, with very low levels of energy efficiency. Overall, Southern Europe’s energy use intensity, when compared to its Western European counterparts, was higher by a factor of more than three;28 additionally, private ownership complicated refurbishment efforts. After the collapse of the Soviet Union, Russia’s GDP dropped by about 25% from 1992 to 1998. Its total primary energy consumption decreased at a lower rate, whereas energy intensity increased by 5–7%.29 In 1996, the energy use intensity of Russia was more than twice that of Canada, which has a similar climate. Since the mid-1990s, Russia has instituted energy regulations and policies to decrease energy intensity; for instance, in 1996, a federal energy conservation law was introduced, and in 1998, a federal program on “energy conservation in Russia” was adopted by the government.29 Despite federal efforts during the 1990s, some progress has been made in certain sectors, but not all. The building sector, in particular, made strides in achieving better energy efficiency, with energy-efficient codes having been adopted both at the regional and federal levels. New federal standards were developed for windows, along with practices such as audits and blower door tests.29 Ukraine is one of the most energy-intensive countries in the world. It first passed an energy conservation law in 1994, and between 1994 and 2005, energy intensity dropped by more than 40%.22 This improvement in energy efficiency did not result from sectoral shifts, but rather technology advancement in individual sectors, particularly the building sector. Despite the governmental-level

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building standard DBN, the contents of the standards have not changed regarding energy efficiency during this period. This period was highly competitive, not only for developed countries such as the United States and EU member states, but also for many developing countries entering the global energy market to compete. Manufacturers in developing countries, like China, received strong financial support from their governments for research and development of advanced energy-efficient technologies, providing leverage over countries which had traditionally dominated this field. For example, in the 1990s, US producers had a 40% market share in photovoltaics (PVs), which fell below 7% in the 2000s.

2007–2010: financial crisis and rapid development of net zero energy building The last recession, which officially lasted from 2007 to 2009, started with the bursting of the housing bubble. The Great Recession began in the United States and then rapidly spread to Europe, affecting all EU member states, other European countries, and Asian and South American countries during 2007–2013. The building and construction industry was one of the hard-hit sectors. In the United States, construction spending reached a historic high at the end of 2006 of approximately $1.1 billion, and then continued to decrease until 2011,30 despite the recession officially ending in 2009. With a slow recovery of the building industry, construction spending did not return to the same level as before the recession until the end of 2016, not taking inflation into consideration. There was a small segment of the building industry that boomed during the economic downturn, however: the green building industry. Leadership in Energy and Environmental Design (LEED) project registrations continued to increase through 2008 and into 2009. Between 2010 and 2011, LEED building registration increased by 9%,31 despite the continued decline of all other sectors in the building industry. The fast development of green and sustainable building shared the common goal of achieving net zero energy, which was the mirror image of the events/developments that occurred during the first oil crisis. Clearly, the oil and economic crises prompted people to utilize resources and energy more efficiently to produce more with limited inputs. During this period, the combination of new knowledge development from the scientific community, advancement in building technologies, natural disasters, and favorable business and political leaderships created a sense of urgency to reduce energy consumption, mitigate the environmental impact of the built environment, and delay the risk of climate change. A variety of federal agency and industry regulators proposed defining guidelines to measure and quantify net zero energy building across the globe. In 2008, the National Science and Technology Council (NSTC) issued the Federal Research and Development Agenda for Net-Zero Energy, High-Performance Green Buildings.32 The National Institute of Standards and Technology (NIST) defined net zero energy buildings as those that produce as much energy as they consume over a defined period and proposed measurement methods.33 These guidelines set an agreeable platform

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and consistent technical guidelines worldwide so that practitioners, researchers, and regulators could communicate in a common language. The European Parliament defined the “nearly zero energy building” as: a building that has a very high energy performance as determined in accordance with Annex I. The nearly zero or very low amount of energy required should be covered to a very significant extend by energy from renewable sources, including energy from renewable sources produced on-site or nearby.34 Furthermore, the EU recommended that by 2020 all new buildings should be nearly zero energy buildings. Research activities and implementation of net zero building flourished. During the recession period, there was a focused effort worldwide to build consensus around practical net zero energy building designs and technical guidelines. During this period (2007–2010), there were 21 built and verified net zero buildings and four buildings designed and built with a net zero goal but not yet verified (see Figure 1.2 for net zero projects worldwide).

2011–2017: financial recovery and blooming of net zero energy building During 2011–2017, the world experienced substantial growth in net zero building due to government and building regulation levels’ promotion. In 2014, California launched building code revisions focused on achieving a zero net energy goal, which were applied to residential and commercial buildings. Title 2428 set a goal of all new residential buildings having zero net energy by 2020

Figure 1.2  Nearly zero energy building projects around the world: building type35 (created by Emma Weber and author)

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and all new commercial buildings by 2030; this title can also be applied to existing buildings. The governor’s office has authorized state agencies to take measures toward achieving a net zero energy goal for 50% of the existing stateowned building stocks by 2025. In Europe, the 2030 communication published by the European Commission in July 2014 underpinned the key role of the building sector36 and recognized that: the majority of the energy-saving potential is within the building sector with 40% of the EU’s energy consumption coming from buildings, and almost 90% of EU building floorspace being privately owned and more than 40% of residential buildings dating from before 1960.29 Directive 2010/31/EU37 on the energy performance of buildings was a major legislative instrument in facilitating the realization of the EU’s low-carbon economy plan. This regulation requires all member countries to “ensure” all new buildings are nearly zero energy buildings by 2020 and all new buildings occupied or owned by public authorities are nearly zero energy by 2018. In Japan, the cabinet approved the Basic Energy Plan in April 2014 after the 2011 Fukushima disaster. The Basic Energy Plan was formulated by the government based on the Basic Energy Policy Law enacted in June 2002 and includes “safety,” “stable supply,” “improvement of economic efficiency,” and “adaptation to the environment.” The initial plan was formulated in October 2003, with second and third plans in March 2007 and June 2010, respectively. A fourth plan was published in 2014 with a goal of all new public buildings being zero energy by 2020 and all new residential buildings being zero energy by 2030. In Japan, energy consumption by building sector constituted 28% of the total energy consumption in 2005.38 In Tokyo alone, the building sector, including commercial and residential, accounted for 77% of greenhouse gas emissions. In December 2006, the Tokyo Metropolitan Government announced its target of reducing greenhouse gas (GHG) emissions by 25% by 2020, from 2000 levels. In the following year, specific policy directions were delineated in the Tokyo Climate Change Strategy and the Tokyo Metropolitan Environmental Master Plan, marking a dramatic departure from the past and progress toward achievement of the announced target. Energetic efforts have been underway to implement programs and systems designed to achieve large and sustained emission reductions.39 Nationwide, the Ministry of Economy, Trade, and Industry (METI) Agency for Natural Resources and Energy set up the Zero Energy House (ZEH) Roadmap review panel in 2015 with the aim of creating guidelines and standards for construction of the ZEH. In 2016, METI started the “Registration System of ZEH Builder” to promote and improve the awareness of ZEH, where “a home builder registering in this system can receive a grant for the construction of ZEH.”40 In China, the building sectors accounted for about 27.5% of total energy consumption in 2011, with a continued increase predicted due to rapid urbanization.41 In response to climate change and environmental degradation, the Chinese central government has employed important energy conservation and emissions reduction regulations. In 2010, the Ministry of Housing

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and Urban-Rural Development (MHURD) established a national green building design (GBD) standard. Since then, ten provisional standards for five different climate zones have been developed and implemented based on the national standard. In 2012, the Ministry of Finance and MHURD jointly issued Implementation Guidance on Accelerating the Development of Green Building in China. In early 2013, the National Development collaborated with the Reform Commission and MHURD to issue the Green Building Action Plan, putting forward the goal of completing 1 billion m2 of new green buildings during the period of the 12th Five-Year Plan, from 2011 to 2015. This action plan called for complete compliance by government-invested buildings, such as offices, schools, hospitals, museums, sport facilities, and banks. China’s 13th Five-Year Plan (2016–2020) includes aggressive goals for green buildings that demand 50% of all new construction to be certified as green-star buildings.

2018–beyond: net zero energy building New goals and regulations call for different design methods and strategies. Most net zero building design strategies have been focusing on technology integration, advanced building materials, and energy-efficient technologies to reduce the building energy load, but are still dependent on electrical grids during peak hours. Among the advanced technologies, two design strategies have emerged as leading solutions: smart lighting systems and advanced building enclosure systems. Integrating daylighting strategies with electric lighting has already been codified in California’s Title 24. The automated daylighting system uses sensors to measure the amount of daylight available in a given space during certain periods and decide whether to adjust the electric lighting to achieve the targeted illumination level required per code. Also, Title 24 requires nonresidential buildings over 10,000 ft2 (929 m2) to install the automated demand response lighting systems. When the overall electric grid reaches its critical peak, the responding lighting system will reduce the supplied power by 15% through the preprogramed automation system. The building enclosure system, which includes façades and roofs, has had a large impact on overall building energy consumption. The heating and cooling loads can be reduced by implementing more energy-efficient enclosure systems. Additional insulation in roofs and attics alone could reduce energy consumption by 10–20%. A wide range of advanced building enclosure systems have been invented and implemented in different climate conditions—from double-skin climate façades to electrochromic glazing (smart glass). Chapter 6 provides a more detailed description of this. As net zero building is increasingly being woven into mainstream practice, its reach and scope can be expanded. As nearly zero energy and net zero energy building have become the new goal and practice standard globally, the roles of building materials and embodied energy or related CO2 emissions become more important.42 Focusing only on energy efficiency entails a clear risk of having an energy-efficient building that does not perform well regarding other environmental criteria. Another growing concern to both developing and developed countries is the environmental impact of an entire building’s service life. The building sector generates about “one third of all waste and is associated with environmental 12

The evolution of net zero energy building

pressures that arise at different stages of a building’s life-cycle including the manufacturing of construction products, building construction, use, renovation and the management of building waste.”43 In the next decades, we could expect to see net zero practice being expanded to include consideration for embodied energy and environmental impact. Chapter 7 proposes an integrated framework moving beyond the current net zero concept and practice.

Conclusion With the large environmental and economic interest in developing net zero buildings that has occurred in the past ten years, understanding and remembering the ecological origin of the concept of energy balance is very important. After several decades of development, energy-efficient practices and sustainable building designs have become a choice—a sectarian one. When a different political party took over power, the policy, funding, and ideology shifted, as explained earlier. Environmental and energy-conscious living has become a trait dividing people into different social groups, with net zero building being the choice of certain groups. However, in nature, in the larger ecosystem in which we live, the laws of energy flow and hierarchy have never changed. What we are missing now is a standard practice and consistent view of integrating all necessary knowledge and methods for achieving net zero energy living. According to the American Institute of Architects (AIA) code of ethics and professional conduct, the architect, during the schematic design phase and as part of the basic services, must discuss with the owners the feasibility of incorporating environmentally responsible design approaches into projects.44 Discussion is far from enough, though. Without enforcement, practitioners rarely proactively push forward a practical, energy-efficient design approach if there is no interest from owners or incentives from legislation. This lack of disciplined requirements is only one reason for today’s selective energy-efficient building design practice—with another being the lack of resources and means. The current approach to achieving net zero energy heavily depends on advanced technology and highly controlled building systems, which creates huge financial and technological barriers for many less resourceful projects and building owners. Understanding the environment and society as a system means thinking about parts, processes, and connections together,34 and this integrated thinking should be the principle for all types of building design. The fundamentally misleading concept of contemporary net zero building is that it is one type of building with one design process. If we instead trace the origin of net zero energy back to its ecological roots, we can consider net zero building as a guiding design principle for all buildings and a professional ethic for all practitioners. Just as all mechanical design must follow the laws of thermodynamics, all building designs should treat the net zero concept as the core consideration, and not as an add-on item.

Note i The Manhattan project was a research project led by the United States with the support of the United Kingdom and Canada during World War II with the aim of producing nuclear weapons. 13

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References 1 Spash, Clive L., ed. Routledge Handbook of Ecological Economics: Nature and Society. Taylor & Francis, 2017. 2 Hernandez, Patxi, and Paul Kenny. “From net energy to zero energy buildings: Defining life cycle zero energy buildings (LC-ZEB).” Energy and Buildings 42, no. 6 (2010): 815–821. 3 Soddy, Frederick. Wealth, Virtual Wealth and Debt. George Allen & Unwin, 1926. 4 Daly, Herman E. “The economic thought of Frederick Soddy.” July 12, 2009. Accessed January 2, 2019. https://billtotten.wordpress.com/2009/07/12/theeconomic-thought-of-frederick-soddy/ 5 Boulding, Kenneth Ewart. Ecodynamics: A New Theory of Societal Evolution. SAGE, 1981. 6 Georgescu-Roegen, Nicholas. “The entropy law and the economic problem.” In Herman E. Daly and Kenneth N. Townsend, eds., Valuing the Earth: Economics, Ecology, Ethics. MIT Press, 1971, 75–88. 7 Odum, Howard T. “Energy, ecology, and economics.” Ambio 2, no. 6 (1973): 220–227. 8 Odum, Howard. Environmental Accounting: Emergy and Environmental Decision Making. John Wiley & Sons, 1996. 9 Pulselli, R. M., Eugenio Simoncini, F. M. Pulselli, and S. Bastianoni. “Emergy analysis of building manufacturing, maintenance and use: Em-building indices to evaluate housing sustainability.” Energy and Buildings 39, no. 5 (2007): 620–628 10 Pulselli, Riccardo Maria, Eugenio Simoncini, and Nadia Marchettini. “Energy and emergy based cost–benefit evaluation of building envelopes relative to geographical location and climate.” Building and Environment 44, no. 5 (2009): 920–928. 11 Butti, Ken, and John Perlin. A Golden Thread: 2500 Years of Solar Architecture and Technology. Cheshire Books, 1980. 12 “MIT buildings: Solar houses.” MIT Libraries. Accessed January 2, 2019. http://libguides.mit.edu/c.php?g=175920&p=1160317 13 Barber, Daniel A. A House in the Sun: Modern Architecture and Solar Energy in the Cold War. Oxford University Press, 2016. 14 Hershey, Robert D., Jr. “10 years after oil crisis: Lessons still uncertain.” New York Times, September 25, 1983. Accessed January 2, 2019. www. nytimes.com/1983/09/25/us/10-years-after-oil-crisis-lessons-still-uncertain. html 15 “Arthur H. Rosenfield.” Wikipedia. Accessed January 2, 2019. https:// en.wikipedia.org/wiki/Arthur_H._Rosenfeld 16 Rosenfeld, Arthur H. “The art of energy efficiency: Protecting the environment with better technology.” Annual Review of Energy and the Environment 24, no. 1 (1999): 33–82. 17 Carter, Jimmy. “Solar Energy Development Bank: Letter to the Speaker of the House and the President of the Senate Transmitting Proposed Legislation, July 27, 1979.” In Public Papers of the Presidents of the United

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States: Jimmy Carter, Book II. United States Government Printing Office, 1980, 1315–1316. 18 “Weatherization Assistance Program.” Energy.gov. Accessed January 2, 2019. https://energy.gov/eere/wipo/weatherization-assistance-program-1 19 Esbensen, Torben Vesti, Torben V. Esbensen, and Vagn Korsgaard. Performance of the Zero Energy House in Denmark. Master’s thesis, Thermal Insulation Laboratory, Technical University of Denmark, 1977. 20 Antonelli, Leoni. “Pioneer award for 1970s ‘zero energy’ house in Denmark.” Passive House Plus, April 19, 2013. Accessed January 2, 2019. https:// passivehouseplus.ie/blogs/pioneer-award-for-1970s-zero-energy-house-indenmark 21 Rosenfeld, A. H., and D. Hafemeister. “Energy-efficient buildings.” Scientific American 258, no. 4 (1988): 78–87. 22 “Rankings: Total energy consumed per capita, 2015.” US Energy and Information Administration. Accessed January 2, 2019. www.eia.gov/state/ rankings/ 23 Joskow, P. L. “US Energy Policy during the 1990s” (no. w8454). National Bureau of Economic Research, 2001. 24 Torcellini, Paul, Shanti Pless, Michael Deru, and Drury Crawley. Zero Energy Buildings: A Critical Look at the Definition. US National Renewable Energy Laboratory and Department of Energy, 2006. 25 Ionescu, C., T. Baracu, G. E. Vlad, H. Necula, and A. Badea. “The historical evolution of the energy efficient buildings.” Renewable and Sustainable Energy Reviews 49 (2015): 243–253. 26 Voss, K., A. Goetzberger, G. Bopp, A. Häberle, A. Heinzel, and H. Lehmberg. “The self-sufficient solar house in Freiburg: Results of 3 years of operation.” Solar Energy 58, nos. 1–3 (1996): 17–23. 27 Kriesi, R. “Comfort ventilation—a key factor of the comfortable, energy-efficient building.” REHVA Journal 3 (2011): 30–35. 28 Kakalejčíková, Zita. How to Improve Residential Energy Efficiency in South Eastern Europe and CIS. Policy discussion brief, Habitat for Humanity International, April 2017. 29 Evans, Meredydd, and Isabel Murray. Efficient Policies? Energy Efficient Policy in Ukraine, Russia, and Belarus. ACEEE, 2006. 30 “Construction spending.” US Census Bureau. Accessed January 2, 2019. www.census.gov/construction/c30/historical_data.html 31 Shutters, Cecilia, and Robb Tufts. “LEED by the Numbers: 16 Years of Steady Growth.” USGBC, May 27, 2016. Accessed January 2, 2019. www. usgbc.org/articles/leed-numbers-16-years-steady-growth 32 “Federal R&D Agenda for Net-Zero Energy, High-Performance Green Buildings.” National Science and Technology Council. Accessed January 2, 2019. www.nist.gov/news-events/news/2008/10/green-buildings-net-zeroenergy-research-agenda 33 Korkmaz, Sinem, David Riley, and Michael Horman. “Piloting evaluation metrics for sustainable high-performance building project delivery.” Journal of Construction Engineering and Management 136, no. 8 (2010): 877–885.

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34 Odum, Howard T., and Mark T. Brown. Environment, Power and Society for the Twenty-first Century: The Hierarchy of Energy. Columbia University Press, 2007. 35 “NZEB Projects around the World—Building Type.” Google Maps. Accessed January 2, 2019. www.google.com/maps/d/u/0/viewer?mid=1p-NomGrAyD2e PVvkgsVgLxMH9Oc&ll=60.79751065189169%2C-58.41975551874998&z=3 36 Guide on Good Practice in Energy Efficiency for Central and South Eastern Europe. European Union, 2018. Accessed January 2, 2018. https://ec.europa. eu/energy/sites/ener/files/documents/brochure_easme_04_web.pdf 37 “Directive 2010/31/EU of the European Parliament and of the Council.” Official Journal of the European Union, May 19, 2010. Accessed January 2, 2019. http://eur-lex.europa.eu/LexUriServ/LexUriServ.do?uri=OJ:L:2010:15 3:0013:0035:en:PDF 38 Murakami, Shuzo, Mark D. Levine, Hiroshi Yoshino, Takashi Inoue, Toshiharu Ikaga, Yoshiyuki Shimoda, and Shuichi Miura. “Energy consumption and mitigation technologies of the building sector in Japan.” In 6th International Conference on Indoor Air Quality, Ventilation & Energy Conservation in Buildings, Sendai, Japan, October 28–31, 2007, Elsevier, 2007. 39 “Climate Change & Energy.” Bureau of Environment, Tokyo Metropolitan Government. Accessed January 2, 2019. www.kankyo.metro.tokyo.jp/en/ climate/index.html 40 “Promotion of Zero Energy Building (ZEB) and Zero Energy Houses (ZEH).” International Energy Agency. Accessed January 2, 2019. www.iea.org/ policiesandmeasures/pams/japan/name-30693-en.php 41 Suganthi, L., and A. A. Samuel.“Energy models for demand forecasting— a review.” Renewable and Sustainable Energy Reviews 16, no. 2 (2012): 1223–1240. 42 Alsema, E. A., D. Anink, A. Meijer, A. Straub, and G. Donze, 2016. “Integration of energy and material performance of buildings: I = E + M.” Energy Procedia 96 (2016): 517–528. 43 “Communication from the Commission to the European Parliament, the Council, the European Economic and Social Committee and the Committee of the Regions.” European Commission, March 27, 2014. 44 B101™—2007 Standard Form of Agreement between Owner and Architect. AIA. Accessed January 2, 2019. http://aiad8.prod.acquia-sites.com/sites/ default/files/2017-02/B101-2007%20Commentary.pdf

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Chapter 2

Principles of zero Metrics and assessment

Existing definitions of net zero buildings While the concept of zero energy building (ZEB) is generally understood, a singular, internationally agreed-upon definition is still lacking, with an excess of seventy low or zero energy/carbon building definitions and standards in circulation worldwide.1 Figure 2.1 illustrates a condensed history of net zero definition development worldwide. Table 2.1 lists several net zero definitions in different countries. While different definitions are possible and sometimes even necessary, a consistent framework or definition would prove helpful for communication among practitioners and researchers. In this section, the four major definitions of acceptable net zero energy building (net zero site, net zero source, net zero cost, and net zero emissions) are defined and applied in real projects in different countries. In 2006, the US National Renewable Energy Laboratory published a paper that was presented at the American Council for an Energy-Efficient Economy (ACEEE) Summer Study conference. In this joint effort between the two institutions, the research team outlined four zero energy building definitions, listed below.2

Net zero site energy building A net zero site energy building is a building that “produces as much energy as it uses, when accounted for at the site.”2 Possible renewable energy generation systems include solar panels and wind turbines. In the calculation of a site energy building, the efficiency of various fuels at the source is not considered.2 Regardless of the electricity source used onsite, if the same amount of electricity generated onsite can balance the consumption within the building boundary, then the zero energy goal has been met. This means that one energy unit of electricity is considered the same as one energy unit of natural gas. However, each fuel source has a different source-to-site energy conversion rate, and for different countries and regions the conversion rate varies as well. For example, the natural gas conversion rate is 1.05 in the United States, with the rate for electricity being between 3.14 and 3.77.10 Theoretically, a lower conversion rate could encourage the use of natural gas as a primary fuel source, but in net zero site energy building, this factor is not considered.

17

Figure 2.1  Linear history of net zero definition development (graphic created by Emma Weber and author)

Nearly zero energy building

Minergie – A

Switzerland

A net zero emissions building produces at least as much emissions-free renewable energy as it uses from emissions-producing energy sources.2

Net zero emissions

European Commission

A net zero cost building receives as much financial credit for exported energy as it is charged on the utility bills.2

Net zero cost

The plug energy building: expenses for space heating, water heating, and air renewal; all electrical appliances and lighting are covered by specially produced renewable energies.4

Nearly zero energy buildings have very high energy performance. The low amount of energy that these buildings require comes mostly from renewable sources.3

A positive energy building (BEPOS) is a building whose overall energy balance is positive.1

A net zero source produces as much energy as it uses, as measured at the source.2

Net zero source

Positive energy building

A net zero site produces as much energy as it uses, as measured at the site. Onsite generation within the building footprint is preferable.2

Definition

Net zero site

Name

France

USA

Table 2.1  Net zero building definitions

Carbon emissions

2006

Source energy (includes embodied energy)

2011

(continued)

Source energy

2010

2009

Cost

Source energy

Site energy

Metric of balance

2006

2006

2006

Year

Zero emissions building

Net primary zero energy building

Zero energy building

Nearly zero energy building

Zero energy building and zero energy house

Efficienhauz Plus

Zero energy house/zero energy building

Net zero energy building

Norway

Sweden (Skanska)

Sweden (SCNH)

Sweden (Boverket)

Japan

Germany

Korea

New Zealand (Zero Carbon Act)

Name

Table 2.1  (continued)

A net zero energy building is low-energy and offsets any energy that is generated from greenhouse gas-emitting fuels with renewable energy generation, such as hydro, solar, and wind.9

n/a

Efficienhauz Plus houses plus have both a negative annual primary energy requirement and a negative annual final energy requirement.8

A net zero energy house has a zero annual net consumption of primary energy (METI).7

A nearly zero energy building has a near net balance of energy imported onsite and energy exported from the site.6

A zero energy building has a net balance of energy imported onsite and energy exported from the site.6

A net primary zero energy building needs to fulfill a net zero primary energy balance between the total energy demand and total energy generation.6

A zero emissions building produces enough renewable energy to compensate for the building’s greenhouse gas emissions over its life span.5

Definition

2018

Site energy

n/a

Site energy

2016 n/a

Source energy

Source energy

2015 2015

Source energy

Source energy

2014 2013

Carbon emissions

Metric of balance

2013

Year

Principles of zero: metrics and assessment

The West Berkeley Public Library was completed in 2013 with a gross floor area of 873 m2 and a total budget of $7,900,000 (see Figures 2.2–2.5). The project owner was the city of Berkeley, as part of a bond program to renew its four public branch libraries.11 This project utilized several passive and active design strategies to reduce the building’s annual energy consumption by 76%, from the AIA 2030 baseline. Table 2.2 illustrates the building’s energy consumption and information, along with those of other buildings.12 The project began by optimizing passive strategies, such as daylighting and natural ventilation and cooling. The conventional 2 × 6 in (5.08 × 15.24 cm) wood studs were replaced by 3 × 8 in (7.62 × 20.32 cm) studs Figure 2.2  West Berkeley Public Library13

Figure 2.3  West Berkeley Public Library section perspective13

21

Principles of zero: metrics and assessment Figure 2.4  West Berkeley Public Library plan13

Figure 2.5  West Berkeley Public Library interior13

to create a larger space of 24 in (60.96 cm), instead of 16 in (40.64 cm), to reduce the structural framing and save more space for insulation. The wall insulation has a higher R-value of 30 and the roof an R-value of 41, compared to standards. A radiant floor system with an insulated slab was also used to prevent condensation

22

Berkeley, USA

2013

Library (new)

873 m

Location

Year

Type

Size

1560 m2 PV (including degradation degree): 2014–2043: 38 kWh/m²/year 2044–2073: 56 kWh/m²/year

289.59

R-30

R-41

U-1.5 SHGC 0.55

Daylight, natural ventilation

Renewable energy generation (kW/m2/yr)

R-value (exterior wall)

R-value (roof)

Window U-value SHGC value

Passive design strategies

Natural ventilation, sun shade

U-0.8 W/m2k

R-70

R-43

223.1621

246.44

775.65

Verified source EUI (kW/m2/yr)

100.73

Natural ventilation, sun shade

0.96

R-55

R-40

32.5 (PV)

n/a

170.35

98.38 m (each house) 2

5180 m 2

27 single-family houses (new)

2012

The Netherlands

Brabantwoningen

Net zero energy cost

Office (renovation)

2014

Sandvika, Norway

Powerhouse Kjørbo

Net zero source

Verified site EUI (kW/m2/yr)

2

West Berkeley Public Library

Building name

Net zero site

Table 2.2  Sample net zero building project information6, 11, 12, 14, 15, 21

Natural ventilation, sun shade

n/a

n/a

n/a

249.84

n/a

305.49

13,656 m2

Mixed-use (new)

2012

Hong Kong, China

Hong Kong Zero Emission Center

Net zero energy emission

Principles of zero: metrics and assessment

from forming on the floor during the cooling season, reducing discomfort. The building’s windows had triple-glazed, low-e curtain walls, daylight sensors were integrated into the control system, and the electrical lighting was LED. All of these strategies together helped to reduce the building’s lighting load, which typically contributes to 30% of a building’s overall energy consumption.

Net zero source energy building A net zero source energy building is a building that “produces as much energy as it uses as measured at the source.”2 Powerhouse Kjørbo (see Figures 2.6 and 2.7) is located in Sandvika, 15 km from Oslo, Norway. The project involved renovating two 1980s office buildings to become energy positive powerhouse buildings. The first building (Building #4) has three floors, and the second (Building #5) has four floors, with a total area of 5180 m2. Entra Eiendom and Skanska Norway are the building owners, and the design firm was Snøhetta. This project represented a pilot study for Norwegian zero emissions buildings (ZEBs).5, 15 The buildings’ enclosures were retrofitted to ensure ultra-low energy consumption through wellinsulated exterior walls, roofs, and glazing. The average U-value of the external walls was reduced from 0.30 W/m2K to 0.13 W/m2K (about R-43), the roof U-value from 0.22 W/m2K to 0.08 W/m2K (about R-70), and the window U-value from 2.50 W/ m2K to 0.80 W/m2K. Furthermore, the airtightness was reduced from an assumed 3.5 air changes per hour (at 50 Pa) to 0.23 measured air changes per hour.16 The buildings’ energy system design focused on the use of energy only when necessary while minimizing the number of sensors and control units. Both buildings have a central heating system with two heat pumps combined with ten geothermal boreholes of around 200 m in depth. The central radiators provide heat during the coldest time of the year, and the heat is circulated through the buildings by ensuring internal doors to the offices are kept open when the rooms are not in

Figure 2.6  Powerhouse Kjørbo17

24

Principles of zero: metrics and assessment Figure 2.7  Powerhouse Kjørbo17

use. During summer time, cooling is provided through natural ventilation and efficient displacement ventilation systems that supply cooler air at lower floor levels and utilize natural convection to enhance the air movement in the rooms. “Free cooling” is provided by circulating the brine from ground probes through a heat exchanger in the ventilation system. The brine temperature is about 8–10 °C, which is often sufficient to cool an entire building without the active cooling system. Also, a natural daylight design was integrated to reduce the need for electrical lighting. With this energy-efficient design, the site energy consumption was reduced to as low as 28 kWh/m2, which was compensated by the energy generated onsite. This project includes Norway’s largest photovoltaic solar energy system—1556 m2 or 311 kWp—which offsets the buildings’ entire lifetime energy demands, including embodied energy. The buildings are designed to annually generate over 200 MWh, or 40 kWh/m2 of heated floor space, which more than covers the buildings’ 20 kWh/m2 load, with the surplus electricity fed into the municipal electricity grid.6 25

Principles of zero: metrics and assessment

Net zero energy cost building A net zero energy cost building is a building that “receives as much financial credit for exported energy as it is charged on.”2 Although the building has a relatively consistent output, utility rates fluctuate, which could propose a challenge to net zero cost building. Accordingly, in certain countries, the focus has been on providing cost-neutral zero energy building, where the construction of a net zero energy building would not entail an extra premium. In 2010 in Brabant in the Netherlands, four municipalities, four corporations, and the Province of North Brabant took the initiative to develop a program of requirements for the Brabantwoning. The starting point was an affordable, energy-neutral, and healthy home for the Brabant region. A very important consideration for Brabantwoning was that the costs fit into the regular budgets of housing corporations. In St. Oedenrode, the first 27 Brabantwoningen were finished, including partial social and market rate housing. All houses have a well-insulated building envelope with high insulation values and triple-glazing. The partition walls between rooms are also insulated with radiant heating. To minimize energy loss through ventilation and infiltration, heat is recovered from the exhaust air with a heat pump boiler and is used to provide hot water. After employing both passive and active sustainable design strategies, the houses’ annual energy consumption was reduced to 10 kWh/m2/ year for the intermediate house with two sides attached to adjacent buildings and 15 kWh/m2/year for the house at the end.18 The electricity consumed is compensated by the electricity generated from solar panels (PV panels) installed on the houses. All houses have a large number of PV panels mounted on the roof, and the housing complex is composed of a series of attached houses (see Figures 2.8–2.10). The 17 intermediate houses each have 15 solar panels, which are expected to produce 3200 kWh/year of electricity, and the ten corner houses with 18 solar panels are expected to produce a total of 3900 kWh/year of electricity.18

Figure 2.8  Brabant house solar panels18

26

Principles of zero: metrics and assessment Figure 2.9  Brabant house18

Figure 2.10  Brabant house18

The solar panels used are Canadian Solar CS6P-P with a module efficiency of up to 16.79%.19 Not only can the electricity produced from the PV panels cover the full electricity need, but it can also produce 35% of the electricity that gets delivered back to the grid, which equals 3.06 kWh/house/year for an intermediate house and 3.672 kWh/house/year for a corner house. All houses are run on electricity; Table 2.3 shows the household energy cost for this project compared to that of a traditional house. The construction cost of these houses has been kept intentionally low, from €179,000 to €35,000 for a house ranging from 100 m2 to 151 m2.20

27

Principles of zero: metrics and assessment

Table 2.3  Brabant house cost compared to traditional house cost18, 20 Traditional house Gas

€100/month

Electricity

€50/month

Gas

€0/month

Electricity

€20/month

Brabant house

Net zero emissions building A net zero emissions building is a building that “produces at least as much emissions-free renewable energy as it uses from emissions-producing energy sources.”2 An example of a zero-carbon building is a mixed-use building located in Kowloon, Hong Kong, the Hong Kong Zero Emissions Center (see Figures 2.11–2.13). It was completed in 2012 at a size of about 14,700 m 2, covering three stories, including a basement. The building includes offices and an exhibition space as well as residential and other commercial functions. The first step was to reduce energy consumption through passive design, and the building successfully reduced energy use by 20%. The tapered and Figure 2.11  Hong Kong Zero Emissions Center21

28

Principles of zero: metrics and assessment Figure 2.12  Hong Kong Zero Emissions Center21

Figure 2.13  Hong Kong Zero Emissions Center21

29

Principles of zero: metrics and assessment

linear built form enhances air flow as well as daylight while reducing solar heat gain. Cross-ventilation is also integrated in the floor plan layout. Since Hong Kong is in a tropical climate zone, preventing excess heat gain during the summer is extremely important for energy saving. Various passive design strategies were applied, such as a deep overhang over the south façade, a low window-to-wall ratio for the southwest façade (10%), a wind catcher, and a shaded roof. To further reduce the energy cost, high-volume lowspeed ceiling fans improve air circulation, desiccant dehumidification helps prevent overcooling of the air for humidity control, and underfloor displacement cooling effectively cools the inhabitants’ space at a higher room supply temperature. The estimated net CO2 reduction by onsite renewable energy generation is 7100 tons over 50 years.

The equation behind the definitions The four net zero definitions, despite having different focuses, share one commonality: they are all based on the concept of energy balance. Emissions and cost are also calculated according to energy consumption. It is fair to say that the current net zero building practice is energy-centric. The energy balance is illustrated in Equations 2A–2D, adopting the approach from Kilbert and Fard as well as William et al.:22 Net zero site energy: rs – m ≥ 0

(Equation 2A)

Net zero source energy: rs − (m + g) ≥ 0 or rs – p ≥ 0

(Equation 2B)

Net zero cost: $rsn − $m ≥ 0

(Equation 2C)

Net zero emissions: rsn − m ≥ 0

(Equation 2D)

where m is the consumption measured by the utility meter onsite, rs is the measured renewable energy produced onsite, p is primary energy (source energy) = m + g, and g is the energy losses in the utility system due to energy conversion and transmission; rsn is the renewable energy produced onsite or nearby by the building owner, $rsn is the income from the renewable energy produced onsite or nearby by the building owner, and $m is the cost of purchased grid-based energy.22

Existing energy calculation methods Although the energy-balancing concept for net zero energy building seems simple at first glance, the detailed calculations and counting can be complex. The basic approach to reach any type of zero balance entails a two-step concept: the first is to reduce the energy demand of the building onsite, and the second is the production of energy onsite to offset the consumption and put it back into the grid. All definitions of net zero building share several basic components: the metric, measurement and accounting method, and balance period.

30

Principles of zero: metrics and assessment

Energy efficiency measurement is vital, and the reliability of measured or predicted energy consumption will have a large impact on whether the net zero goal can be accomplished. Measurements and data need to be presented in a friendly and transparent way to help decision-makers visualize their options, cost, and payback. Energy simulation can guide decision-making; therefore, it is useful to understand the different types of scientific methods behind it. The detailed energy calculation methods that relate to all components, such as the building envelope and HVAC system, are quite diverse. All generally employ a mathematical model of each building component and a transient analysis of heat flow in the building. In the following sections, we will discuss several major calculation methods currently being used in building energy simulation (this is not an exhaustive list)

Transfer function method The transfer function method (TFM) is one of the most conventional approaches used for the transient heat transfer calculation23 (transient heat transfer refers to heat transfer through convection) and has been implemented in quite a few simulation programs, such as EnergyPlus and TRNSYS. The transfer function method for computing zone thermal response was introduced in the ASHRAE Handbook of Fundamentals24 without ever being published in a peer-reviewed archival publication.25 This method relies on a set of tabulated room transfer function coefficients and consists of a time series that allows the calculation of inside and outside surface heat flows using current and past values of surface temperatures and past values of heat flows themselves.26 Because the initial method did not undergo a validation and verification process in the scientific community, it had stirred up criticism since its original 1972 version. The American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) community realized a more rigorous method was needed, so in 1997 ASHRAE revised the TFM method based on a study,27 followed by a series of research projects, resulting in a new procedure for determining current commonly used methods being included in the ASHRAE handbook. One of the issues with this current method is its instability when large time steps are applied in the calculation, potentially causing abrupt changes in the final simulation results.

Thermal response factor method The thermal response factor method (TRFM) is another commonly used approach for calculating transient heat transfer. In the early days of building performance simulation, it was impossible to compute and solve a detailed energy balance on each surface (building layers) for each time step due to computational capacity. In 1967, Stephenson and Mitalas introduced the response factor, also known as the weighting factor method, to minimize the computational burden.28 This method was based on the balance between the current value of the cooling load and the current and past values of heat gains:23 ∙θ

= ∑jj = 0 Rj qθ-jδ

(Equation 2E)

31

Principles of zero: metrics and assessment

where J is the number of response factors actually used, q is the transient heat conduction, R is the response factor, δ is the time interval, and θ is the time. In fact, many earlier simulation tools such as DOE-2 adopted this method to solve opaque retaining structure heat transfer and use the cooling load coefficient method to calculate the room load temperature.23 In this method, one can assume the coefficients of the building envelope are constant, so the room temperature is set as a constant value as well, which could lead to certain discrepancies compared to the actual conditions. Additionally, for a building system, such as a radiant floor (creating the varied air temperature in the room), this method would not work.

Radiant time series method The first two methods, TFM and TRFM, have been under development since the 1950s and were primary methods for many years until the creation of the radiant time series method (RTSM). Both TFM and TRFM are representations of an infinite series with a trade-off between the accuracy of the calculation and the computational requirements.29 RTSM was introduced for a cooling load calculation.29 It was invented to account for air temperature variation. RTSM is based on a heat balance approach between the outside and inside, and uses periodic factors to model transient conductive heat transfer.23 RTSM in many ways follows TFM, but differs in the computation of conduction heat gain and in the determination of the cooling loads once the hourly heat gains are known.

Regression method Among the greatest difficulties in these early calculation methods were the variations and layers of building components. A building’s energy performance is affected by various building variables, including indoor temperature, building envelope, and mechanic system setup. A multiple linear regression method could be used to predict the thermal load based on the regression of recorded building operational data. For existing buildings, the actual building could be used; for new buildings, the data of a building with a similar function, scale, and environmental condition could be used for prediction. The Monte Carlo framework is usually adopted for the multiple linear regression model, and software such as EnergyPlus can be used as a simulation tool. An advantage of using the regression method is that it considers the actual previous energy performance to predict future performance, leading to greater accuracy in results.

Artificial neural networks An artificial neural network (ANN) is a generic denomination for several simple mathematical models that try to simulate the way a biological neural network (e.g., the human brain) works.30 The main characteristic of ANN is the capacity to learn the “rules” that control a physical phenomenon under certain conditions; an ANN could potentially be used as an effective method to predict building energy consumption using a learning process based on previous knowledge of actual

32

Principles of zero: metrics and assessment

building energy consumption.23 This learning process, called machine learning, has been applied to various disciplines. The development of such machine learning and an artificial neural network is based on the observation of biological neural network behavior. Since many variables influence a building’s energy performance in similar ways to how a complicated biological neural network works, using this method presents a unique potential. ANNs learn from examples, are fault-tolerant, can handle noisy and incomplete data, and are able to deal with non-linear problems; furthermore, once trained, they can perform prediction and generalization at high speeds.31 ANNs have been applied in different engineering cases in the fields of HVAC system design, solar design, control systems design, and other complex transformation process modeling. By using ANNs, Bektas and Aksoy predicted that buildings’ energy needs would benefit from orientation, insulation thickness, and transparency ratio.32 Kreider and Wang applied ANNs to determine with good accuracy the energy use of chillers by using hourly averaged data collected from the system,32 and Kalogirou and Bojic used ANNs to predict the energy consumption of a passive solar building.33 Olofson and Anderson developed a neural network that makes long-term energy demand predictions based on short-term measured data with a high prediction rate of 90–95%.34 There are many more examples and studies in the last decade of the application of ANN in energy-efficient building designs. Most current commercially available energy modeling programs are time-consuming and inflexible; therefore, ANNs provide a cost-effective and flexible alternative that offers more support in achieving the net zero energy goal.

Measurement metrics Four types of metrics are used to measure the net zero balance in practice: primary energy (source energy), energy cost, carbon emissions, and site energy, all of which align with the four definitions of net zero buildings. Characteristics, advantages, and disadvantages of each metric are discussed below and illustrated in Table 2.4. Metrics are needed for achieving the net zero goal, with some being more difficult or holistic than others and certain metrics being closely related; for instance, source energy is closely related to carbon emissions. The metric choice has an impact on the design decision-making, so it is important for the design team and building owners to first decide which metric is appropriate and fully understand its benefits and disadvantages.

Primary energy (source energy) Primary energy is energy embodied in sources where human-induced extraction or capture—with or without separation from contiguous materials, cleaning, or grading—must be undertaken before the energy can be traded, used, or transformed. It is an energy form found in nature that has not been subjected to any human engineering conversion or transformation process.35 Primary energy sources include oil, coal/peat/shale, natural gas, hydro, and nuclear. Primary energy is one the most commonly accepted metrics used to measure a building’s

33

•• Does not account for differences between fuel types. •• Not fair to certain locations that lack sufficient renewable energy resources •• Does not account for non-energy impact related to fuel types (pollution) •• May not reflect impact to national grid for demand, as extra PV generation can be more valuable for reducing demand with onsite storage than exporting to the grid •• Requires a net-metering agreement so that exported electricity can offset energy and non-energy charges •• Fluctuating energy rates make it difficult to track over time

•• Easy to measure and implement •• Verifiable onsite •• Easy for building team to understand and communicate •• Encourages energy-efficient building designs

•• •• •• •• ••

•• Accounts for non-energy impact between fuel types (GHGs, smog) •• More comprehensive •• Can be used as a universal framework and applicable to all countries •• Encourages long-term and holistic decision-making

Secondary energy (site energy)

Energy cost

Carbon emissions

•• Needs country-specific emission factors •• Needs a standardized method to calculate the emission related to different fuel types

•• Difficult for team to understand and communicate •• National energy infrastructure plays a large role in primary energy accounting, which might discourage energy-efficient designs •• Does not account for non-energy impact related to fuel types (pollution)

•• Able to equate energy value of fuel types used at site •• Better model for impact on national energy system •• Fair to all sites/projects

Primary energy (source energy)

Easy to measure and implement Appealing to building owners Allows for demand-responsive control Verifiable from utility bills Easy to track

Minuses

Pluses

Metric

Table 2.4  Comparison of metrics3

European Union United Kingdom

United States European Union

United States China South Korea

European Union United States

Countries applied in

Principles of zero: metrics and assessment

energy efficiency. The quantity of different energy sources used onsite in the building (electricity, natural gas, etc.) is converted from primary energy that is located far away from the building. Each primary energy source has a different conversion rate, but primary energy does not register on the meter or in the electricity bill of the building. The case is similar to carbon emissions, concerning the energy consumed by the building. Variations in conversion rates are the result of the national electricity grid structure. In the United States, fossil fuels continue to account for the bulk of US energy consumption and amounted to 81% of the total energy consumption in 2016.36 In Germany, the dominant primary energy source is fossil fuels, followed by nuclear power, biomass, and other renewable energy sources, whereas in France, the dominant primary energy source is nuclear, which accounts for about 74.5% of total energy consumption, followed by hydroelectricity at 16.3%. In contrast, 64.4% of electricity in South Korea derives from fossil fuels, followed by nuclear at 31.2%, with 3.3% generated from renewable sources. In Brazil, 69.3% of electricity is from hydroelectric plants, followed by fossil fuel plants at 18%, and 10.5% of electricity generated from renewable sources.37 Figure 2.14 illustrates the primary energy structures in different countries. By focusing on the primary energy, energy consumption can be calculated in broader and more holistic terms. Not only has energy consumption of the building’s occupants onsite been included, but also the energy used to deliver the electricity to the site. From this perspective, the measurement

Figure 2.14  Primary energy generation resources38

Energy Generation (Mtoe/capita) Kuwait United Arab Emirates Chile Brazil Singapore India Korea Japan China Russia Iceland Italy France Belgium UK Netherlands Sweden Germany Canada Switzerland US 0

50

100

150

200

Share of renewables in electricity (%) Share of coal in electricity (%) Share of natural gas in electricity (%)

250

300

350

400

Share of nuclear in electricity (%) Share of fossil fuels in electricity (%) TOTAL

35

Principles of zero: metrics and assessment

of primary energy is more accurate and comprehensive; however, it does require an experienced energy modeler and engineers’ input. Meanwhile, it is difficult for clients and the public to comprehend the concept of paying for something that is out of their control and sight.

Secondary energy (site energy) Secondary energy, or site energy, is energy embodied in commodities that come from human-induced energy transformation. We can think of site energy as the energy being delivered and consumed on the building site. Site energy does not include the energy used upstream in power plants or lost during delivery, and this omission could distort the accuracy of energy accounting. However, site energy is easy to understand and relatively easy to monitor. Due to its practicality, site energy has been chosen as a prevailing metric to measure building energy efficiency in various countries. In the ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers) 2020 Vision report, site energy is the metric chosen through an agreement of understanding among important industry partners: the American Institute of Architects, USGBC (US Green Building Council), and IESNA (Illuminating Engineering Society of North America). Currently in the United States, site energy is the dominant metric used to measure building efficiency, while in the majority of European countries, source energy is the dominant metric. Some Asian countries, such as Japan and South Korea, also choose to use site energy as the primary metric.

Energy cost Zero energy cost building is addressed in several different ways. The amount of money the utility company pays the building for the renewable energy generated onsite that gets exported back to the utility grids needs to be at least equal to the amount of money the building pays for utilities to keep the building operational over the year. The energy generated onsite fluctuates over the year during seasons when renewable energy resources are not sufficient. Besides seasonal changes, the cost of energy also fluctuates according to time and political intervention through tax rates and incentives. Some projects purchase renewable energy offsite to supplement the onsite renewables if the total cost can be balanced over the year. The realization of a balance of a zero energy cost depends on the market availability and access to affordable renewable energy resources. Most of the time, without government subsidies or tax incentives, it isn’t possible for large-scale commercial building to achieve such a goal. Even though building owners might be more interested in using the cost of energy to measure building performance, it may be difficult, or even impossible, because of the utility rate structure. Many rate structures will give credit for energy returned to the grid, but will not allow this to go below zero on an annual basis. As a result, there is no way to recover costs incurred by fixed and demand charges.39 Electricity prices are often distorted by governmental incentives of policies, which is particularly true in developing countries still in the process of establishing and maturing their energy infrastructure system. Another potential problem of this metric is that when cost is used as a measurement unit, people’s attention will shift to

36

Principles of zero: metrics and assessment

expenses instead of energy efficiency. Conversely, there are benefits of using cost as a metric. One benefit is its attraction to building owners; if the building owner will own and operate a building in the long term, the direct financial benefit of paying no net utility bills could be a determining factor. The second advantage is that it is easy to track and understand when energy spending can be assigned financial amounts.

Carbon emissions European countries also use carbon emissions to measure net zero building performance. The carbon emissions metric is the measurement of all carbon emissions related to the energy consumed onsite (site energy). A zero carbon building is a building that, over a year, does not have positive energy consumption that entails CO2 emissions. For instance, in 2006, the British government set “a target for all new homes to be zero carbon within a decade” under the leadership of then-chancellor Gordon Brown. The requirement was canceled in 2015 with an aim to reduce regulations on housebuilders to stimulate the economy. After the 2016 Paris Climate Agreement, the United Kingdom planned to enshrine in law a long-term plan to reduce carbon emissions to zero by 2050, and this new shift could reintroduce building-related regulations and design guidelines. Other definitions include not only carbon emissions caused by building operations, but also emissions associated with embodied energy, such as energy generated in construction, energy embedded in building materials, and carbon emissions of commuting to and from the building. For instance, New Zealand has included embodied and transportation

Figure 2.15  Comparison of CO2 emissions per capita36

CO2/population (tCO2/capita) Kuwait United Arab Emirates Chile Brazil Singapore India Korea Japan China Russia Iceland Italy France Belgium UK Netherlands Sweden Germany Canada Switzerland US 0

5

10

15

20

25

37

Principles of zero: metrics and assessment

carbon emissions in the overall measurement.39 The advantage of using carbon emissions as a metric is to encourage long-term thinking and shift attention from immediate energy consumption and financial gain to holistic and longterm environmental impact reduction. The initial driver that started the net zero movement might be energy conservation, but the ultimate goal is to preserve resources and energy so that we can achieve a balance in the energy resource consumption environment in a systematic way. Figure 2.15 shows CO2 emissions per capita in different countries.

Conclusion It is important to obtain basic scientific knowledge of net zero energy building design, measurement, and verification in order to set up acceptable design guidelines and practice principles. As described in this chapter, there are different definitions, focuses, and measurements of “net zero” across the globe. Achieving net zero is not only a technical aspiration, but also a social and political movement. Unlike fundamental physics, which is commonly accepted in law, building science is still in its adolescence. There is still much need for research and experimentation as the net zero energy building practice is incomplete, with varying results that are both positive and predictable as well as unintended and negative. Accordingly, the next two chapters will attempt to explain this two-sided story.

References 1 Williams, Joseph, Rachel Mitchell, Vesna Raicic, Marika Vellei, Graham Mustard, Amber Wismayer, Xunzhi Yin et al. “Less is more: A review of low energy standards and the urgent need for an international universal zero energy standard.” Journal of Building Engineering 6 (2016): 65–74. 2 Torcellini, Paul, Shanti Pless, Michael Deru, and Drury Crawley. Zero Energy Buildings: A Critical Look at the Definition, Preprint No. NREL/CP-550-39833. National Renewable Energy Laboratory, 2006. 3 Janssen, Rod. Nearly Zero Energy Buildings: Achieving the EU 2020 Target. European Council for an Energy Efficient Economy, April 13, 2011, 1–16. 4 “Minergie-A.” MINERGIE. Accessed January 2, 2019. www.minergie.ch/de/ verstehen/baustandards/minergie-a/ 5 Dokka, T. H., I. Sartori, M. Thyholt, K. Lien, and K. Byskov Lindberg. “A Norwegian zero emission building definition.” In Proceedings from Passivhus Norden. Gothenberg, October 15–17, 2013. 6 “Powerhouse Kjorbo—the house that heats itself.” Skanska, February 20, 2014. Accessed January 2, 2019. https://group.skanska.com/media/articles/ powerhouse-kjorbo---the-house-that-heats-itself/ 7 “Japan.” International Energy Agency. Accessed January 2, 2019. www.iea. org/countries/membercountries/japan/ 8 Ascione, Fabrizio, Nicola Bianco, Olaf Böttcher, Robert Kaltenbrunner, and Giuseppe Peter Vanoli. “Net zero-energy buildings in Germany: Design, model calibration and lessons learned from a case-study in Berlin.” Energy and Buildings 133 (2016): 688–710.

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9 Hernandez, Patxi, and Paul Kenny. “From net energy to zero energy buildings: Defining life cycle zero energy buildings (LC-ZEB).” Energy and Buildings 42, no. 6 (2010): 815–821. 10 Deru, Michael, and Paul Torcellini. Source Energy and Emission Factors for Energy Use in Buildings (revised, no. NREL/TP-550-38617). National Renewable Energy Laboratory, 2007. 11 “West Branch of the Berkeley Public Library.” American Institute of Architects. Accessed January 2, 2019. www.aiatopten.org/node/471 12 “AIA 2030 Design Data Exchange.” American Institute of Architects. Accessed January 2, 2019. https://2030ddx.aia.org/helps/Baseline%20Guidance 13 “West Branch of the Berkeley Public Library.” American Institute of Architects. Accessed January 2, 2019. http://www.aiatopten.org/node/471 14 “Powerhouse Kjørbo.” PowerHouse. Accessed January 2, 2019. https:// www.powerhouse.no/prosjekter/kjorbo-2/ 15 Kristjansdottir, T. F., C. S. Good, M. R. Inman, R. D. Schlanbusch, and I. Andresen. “Embodied greenhouse gas emissions from PV systems in Norwegian residential zero emission pilot buildings.” Solar Energy 133 (2016): 155–171. 16 Thyholt, M., T. H. Dokka, and B. Jenssen. “Powerhouse Kjørbo: A plusenergy renovation office building project in Norway.” Research Centre on Zero Emission Buildings, 2013. Accessed January 2, 2019. www.zeb.no/ index.php/en/conference-papers/item/455-powerhouse-kj%C3%B8rbo-aplus-energy-renovation-office-building-project-in-norway 17 “Powerhouse Kjørbo.” Snøhetta. Accessed January 2, 2019. https://snohetta. com/projects/40-powerhouse-kjorbo 18 “Brabantwoning.” Archiservice. Accessed January 2, 2019. www.archiservice. nl/?cat=7 19 “60-Cell Standard Panels.” CanadianSolar. Accessed January 2, 2019. www. canadiansolar.com/solar-panels/standard.html 20 “Brabantwoningen.” Rijksdienst voor Ondernemend Nederland. Accessed January 2, 2019. www.rvo.nl/initiatieven/energiezuiniggebouwd/brabant woningen 21 “Zero carbon building.” Hong Kong Zero Emissions Center. Accessed January 2, 2019. http://zcb.hkcic.org/ 22 Williams, Joseph, Rachel Mitchell, Vesna Raicic, Marika Vellei, Graham Mustard, Amber Wismayer, Xunzhi Yin et al. “Less is more: A review of low energy standards and the urgent need for an international universal zero energy standard.” Journal of Building Engineering 6 (2016): 65–74. 23 Wang, Haidong, and Zhiqiang John Zhai. “Advances in building simulation and computational techniques: a review between 1987 and 2014.” Energy and Buildings 128 (2016): 319–335. 24 “ASHRAE Handbook of Fundamentals.” American Society of Heating, Refrigerating and Air-Conditioning Engineers, 1972. Open Library. Accessed January 2, 2019. https://openlibrary.org/books/OL5332975M/ASHRAE_ handbook_of_fundamentals 25 Gasparella, Andrea, Giovanni Pernigotto, Marco Baratieri, and Paolo Baggio. “Thermal dynamic transfer properties of the opaque envelope: Analytical

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26

27

28 29

30

31

32

33 34 35 36 37

38 39

40

and numerical tools for the assessment of the response to summer outdoor conditions.” Energy and Buildings 43, no. 9 (2011): 2509–2517. Delcroix, Benoit, Michaël Kummert, Ahmed Daoud, and Marion Hiller. “Improved conduction transfer function coefficients generation in TRNSYS multizone building model.” Presentation at 13th Conference of International Building Performance Simulation Association, Chambéry, France, 2013. De Dear, Richard, Gail Brager, and Donna Cooper. Developing an Adaptive Model of Thermal Comfort and Preference. Final Report ASHRAE RP-884, March 1997. Accessed January 2, 2019. www.cbe.berkeley.edu/research/ other-papers/de%20Dear%20-%20Brager%201998%20Developing%20 an%20adaptive%20model%20of%20thermal%20comfort%20and%20 preference.pdf Stephenson, Donald George, and G. P. Mitalas. “Cooling load calculations by thermal response factor method.” ASHRAE Transactions 73 (1967): 1–7. Spitler, Jeffrey D., and Daniel E. Fisher. “On the relationship between the radiant time series and transfer function methods for design cooling load calculations.” HVAC&R Research 5, no. 2 (1999): 123–136. Neto, Alberto Hernandez, and Flávio Augusto Sanzovo Fiorelli. “Comparison between detailed model simulation and artificial neural network for forecasting building energy consumption.” Energy and Buildings 40, no. 12 (2008): 2169–2176. Kalogirou, S. A., and M. Bojic. “Artificial neural networks for the prediction of the energy consumption of a passive solar building.” Energy 25, no. 5 (2000): 479–491. Ekici, B. B., and U. T. Aksoy. “Prediction of building energy consumption by using artificial neural networks.” Advances in Engineering Software 40, no. 5 (2009): 356–362. Kalogirou, S. A. “Applications of artificial neural-networks for energy systems.” Energy Systems 67, nos. 1–2 (2000): 17–35. Olofsson, T., and S. Andersson. “Long-term energy demand predictions based on short-term measured data.” Energy and Buildings 33, no. 2 (2001): 85–91. “Primary energy.” Wikipedia. Accessed January 2, 2019. https://en.wikipedia. org/wiki/Primary_energy “IEA Energy Atlas.” US Energy Information Administration. Accessed January 2, 2019. www.eia.gov/todayinenergy/detail.php?id=30652 “The World Factbook.” Central Intelligence Agency. Accessed January 2, 2019. www.cia.gov/library/publications/resources/the-world-factbook/index. html Torcellini, Paul A., and Drury B. Crawley. “Understanding zero-energy buildings.” ASHRAE Journal 48, no. 9 (2006): 62. Nsaliwa, Dekhani, Robert Vale, and Nigel Isaacs. “Housing and transportation: Towards a multi-scale net-zero emission housing approach for residential buildings in New Zealand.” Energy Procedia 75 (2015): 2826–2832.

Chapter 3

Predicted impact of net zero building

Trends and opportunities Based on estimates from building inventory studies, currently there are approximately 500 net zero energy commercial buildings and 2000 net zero energy housing units worldwide. The European Union has the highest number of net zero buildings, due to government-sponsored retrofit programs and the early adoption of building energy efficiency policies,1, 2 and North America ranks second. Overall, residential projects have the largest concentration of net zero buildings, whereas single-family houses present the highest number of net zero projects. Within the residential sector, net zero buildings used to be primarily single-family houses, but in the past five years there has been an uptick in the pursuit of net zero energy in multi-family projects. The second-largest concentration is in commercial office buildings; the development of commercial net zero projects has steadily increased in the last decade, the majority of which are publicly owned properties.1 From 2010 to 2018, there was considerable growth in the net zero building market. In Europe, between 2010 and 2014, the share of new buildings built, according to official near-zero energy building definitions, increased from 5.9% to 9.37% in Austria, 4.26% to 22.19% in Belgium, 17.15% to 93.75% in France, 8.7% to 22.3% in Italy, and 5.39% to 13.99% in Germany.3 The total increase of net zero buildings in the United States from 2012 to 2018 was 700%, including 67 verifiedi and 415 emergingii net zero buildings.1 Overall, growth can be found across all building types, including high-energy use types, such as laboratories and healthcare centers; however, the most growth in recent years has been in institutional buildings, including K–12, colleges, and university buildings. In the following decades, schools will continue to have the largest share of net zero energy-verified buildings due the early adoption of design standards and polices by certain public school districts,1 and this is a global trend. According to the Intergovernmental Panel on Climate Change (IPCC) report in 2014, to limit the global temperature change to a rise of no more than 2–4 °C, we need to cut global carbon emissions by 80%.4 This would require the cooperation of all industries, from agriculture to transportation, to collectively achieve this cut. However, several industries are unlikely to achieve this goal within the time frame outlined by the Paris Agreement. Regardless, this demand, as well as

41

Predicted impact of net zero building

efforts toward energy efficiency and a reduction in CO2 emissions, have already created change and will continue to act as a positive force, particularly in developing countries. It is expected that 60 million new homes will be built in India between 2018 and 2024.5 By 2020, it is predicted that China will represent 19% of all global construction output, with most occurring in urban areas. Furthermore, certain experts forecast that market growth will be driven by Indonesia and the Philippines by 2020. These areas are a few examples that demonstrate how the next decades will experience a concentration in urbanization in Asia and Africa, with a construction boom predicted to occur in most developing countries. However, most developing countries currently do not have clearly defined energyefficient design guidelines, strategies, and regulations to achieve the net zero goal, which presents immense opportunities as well as challenges.

Direct benefits of net zero building There are direct and indirect benefits of pursuing net zero energy buildings (see Table 3.1 and Figure 3.1). Research has shown that improving the energy performance of buildings could result in the direct benefit of reduced utility costs and increasing energy saving, conservation of resources including water, and improvements in direct work productivity and the occupants’ well-being. Another direct benefit is an increase in the buildings’ resale value. Indirect benefits include labor force building, community building, and cultural and societal changes.

Energy and resource conservation Globally, the building industry is a major contributor to carbon emissions, and buildings consume roughly 30% of the total energy worldwide. The construction and operation of the current building stock accounts for around 40% of total energy consumption in the European Union6 and 30% in the United States.7 Reducing energy consumption continues to be the top reason for energy-efficient building. Based on the World Green Building Trends 2016 report produced by Dodge Data & Analytics, 66% of survey respondents selected “reduce energy consumption” as their main motivation for building green. The results were drawn from respondents from 69 countries, with statistically significant results on the highlighted 13 countries.8 Among the 13 countries highlighted, Singapore ranked the highest, with 84% of Singaporean respondents choosing “energy

Table 3.1  Direct and indirect benefits/impacts of building green Direct impact

Indirect impact

Energy saving

Labor force building

Resource saving

Community building

Water saving

Societal change

Productivity increase Building resale value increase

42

Predicted impact of net zero building Figure 3.1 Direct and indirect benefits/ impacts of building green (by Emma Weber and author)

conservation” as their number one reason for building green. The United States ranked second, with 76% of American respondents’ votes, and Germany and the United Kingdom ranked third at 71%. “Protecting natural resources” was the second most important reason for global green building, particularly for those countries where the extraction and exportation of raw materials plays an important economic factor, including Brazil (47%), Saudi Arabia (42%), South Africa (46%), Australia (50%), and China (49%). Finally, “reducing water consumption” ranked third, with 31% of the survey takers voting for this option globally.8 To achieve the net zero goal, the buildings must reduce at least 80% of energy consumption compared to the current baseline building energy code. The Passivhaus (Germany) standard is considered as one the most stringent and internationally influential standards, with at least 25,000 certified projects in Europe. According to this standard, buildings should be designed so that the annual energy demand for heating and cooling does not exceed 15 kWh/m2/year for a net living space.9, 10 Meanwhile, in the United States, the current national average energy efficiency of a single-family detached house is 215 kWh/m2/year—14 times higher

43

Predicted impact of net zero building

than that of the Passivhaus standard. The average verified net zero building energy use intensity in the United States, until 2016, was around 60 kWh/m2/year,iii which is one third of the national average. However, focusing only on creating new energy-efficient buildings is not sufficient, as by 2020 the existing building stocks (more than 20 years old) will represent the majority.11 If we could retrofit existing single-family detached houses that are more than 20 years old from 215 kWh/m2/ year to 60 kWh/m2/year, then the overall utility savings in the United States could be as high as 41,695 kWh/year, which could power an elementary school classroom (600 W) for 7.9 years. As pointed out in Chapter 2, the most commonly used net zero building definitions are based on operational energy consumption. Various researchers have studied final energy use in the entire life cycle of buildings and have shown that the operation phase contributes significantly to the life cycle’s final energy use of buildings. Ramesh et al.12 conducted a literature review study of life cycle final energy analyses of 73 residential and office buildings in Northern and Central Europe, Canada, tropical regions of Asia, and Australia. Their results suggested that final operation energy use contributes to about 80–90% of life cycle energy use in residential buildings. Space heating and cooling of buildings, for example, contribute a substantial proportion of the total operation energy. So, from a longterm and life cycle perspective, net zero operational energy building can produce large cost-saving benefits for building owners and operators. Table 3.2 shows the operational energy saving and water conservation of four sample net zero buildings that were included in Chapter 2.

Productivity and well-being benefits The relationship between indoor environmental quality and human health and productivity has been studied extensively worldwide since the 1990s. Poor indoor environmental quality factors have been linked to human health impacts and decreases in productivity, including factors such as air quality, thermal conditions, lighting quality, and noise levels. In a 1993 study in the United Kingdom, self-reported productivity loss was found to be linked to the prevalence of sick Table 3.2  E  nergy saving and water conservation of four sample net zero buildings (see Chapter 2)

44

Building name

Country

Energy reduction (without renewable energy)

Water reduction

West Berkeley Public Library

USA

76% (compared to national average)

58%

Powerhouse Kjørbo

Norway

90% (after renovation)

10%

Brabantwoningen

Netherlands

148% (compared to national requirements)

—

Zero Carbon Building

Hong Kong, China

45% (compared to current standards)

—

Predicted impact of net zero building

building syndrome13—a situation in which the occupants of a building experience acute health- or comfort-related effects that seem to be linked directly to the time spent in a building.14 In Canada, Menzies et al. observed impaired performance due to the continuous performance of computerized and symbol-digit substitution tasks among office workers in a Canadian building who reported any sick building syndrome symptoms.15 In Denmark, a group of researchers led by Professor Wargocki found that for typing tasks, employees worked significant more slowly when a pollution source was present in the office environment. The researchers concluded that reducing the pollution load on indoor air proved to be an effective means of improving the comfort, health, and productivity of building occupants.16 Many studies indicate that small differences in temperature of only a few °C can influence workers’ speed or accuracy by 2–20% in tasks such as typewriting, learning performance, reading, multiplication, and word memory.17 Several studies have linked better lighting, thermal comfort, and air quality to higher test scores.18, 19, 20 Sustainable building has a holistic goal of consuming less energy while providing high indoor quality to occupants. In fact, many passive and active energy-efficient design strategies will help to improve lighting quality and indoor air quality. Sustainable buildings have been shown to increase worker productivity by 20–25% through improved working conditions, such as increased natural air and light and reduced exposure to toxic materials. Other research also suggests that aging school facilities and inefficient equipment have a detrimental effect on academic performance, which can be reversed when schools are upgraded.21 Studies from the industry and academia demonstrate the savings associated with green building, which not only include a direct increase in productivity, but also an indirect productivity gain through a reduction in health and safety costs and increased retention rate. Productivity is defined as the output of any process, per unit of input, which directly relates to the performance of the process elements, including the workers.22 In 1994, two researchers, one from the US Department of Energy and the other from the Rocky Mountain Institute, discovered an energy-efficient design that could result in productivity gains of 6–16% by providing efficient and high-quality lighting to reduce errors and manufacturing defects.23 Heerwagen and Hase found significant productivity gains associated with bringing natural elements into buildings, and reported that employees’ overall positive feeling about the environment increased by 60%.24 In 2009, a team from the CBRE and the University of San Diego surveyed 154 buildings, containing over 2000 tenants, that were deemed green either by the Energy Star label or LEED certification. The team collected responses from 534 tenants, and results showed that 12% of the tenants strongly agreed that employees were more productive, and 42.5% agreed that employees were more productive specifically in a green building,25 indicating that over 50% of the employees agreed that an increase in productivity occurred in those green buildings. Singh et al. studied two LEED buildings in Lansing, Michigan and found substantial reductions in self-reported absenteeism and affected work hours because of perceived improvements in health and well-being.26 In 2010, another research team from the University of Cambridge, Steemers and Manchanda, surveyed 12 office buildings in the United Kingdom

45

Predicted impact of net zero building

and India to demonstrate the relationships between sustainable building design and the occupants’ well-being. Their overall conclusion indicated that energy use in typical office buildings is inversely correlated with the well-being of the occupants, and that more energy use does not improve the occupants’ well-being.27 Lastly, research showed that providing building occupants with control over their local environment could increase the occupants’ satisfaction, and consequently their well-being and productivity. Table 3.3 shows selected studies of correlation between green buildings and productivity. On the contrary, the overcontrolled centralized mechanical system results in reduced occupant control, and this often correlates with reduced occupant satisfaction. Therefore, the correlation between a reduction in localized control of the indoor environment and workers’ satisfaction and productivity is still debatable.

Asset value–market demand Client demand for green building is very high across Europe, particularly in the United Kingdom, for several reasons. Firstly, improving the energy efficiency of buildings provides a potential increase in market value through recognition of green building practices and labeling, such as a LEED, BREEAM (Building Research Establishment Environmental Assessment Method), or net zero energy building. Especially for school buildings, because of their function, highperformance or energy-efficient buildings are particularly valuable for institutional clients and local governments. An increasing number of net zero and positive energy buildings are serving as living laboratories for educational purposes. Secondly, market demand has consistently been an important trigger for green building in the past ten years. According to the World Green Building Trends 2016 report, client demand for green building increased from 34% in 2008 to 40% in 2015. Clearly, recognition by owners of the benefits of building green is critical to sustaining green market growth globally:8 The survey shows that global green building activity continues to double every three years. . . . More people recognize the economic and productivity value that green buildings bring to property owners and tenants, along with the energy and water benefits to the environment, which is driving the green building industry’s growth. It’s a win-win for people, planet and the economy.28 Other than developed countries, many developing countries have seen a rapid rise in green buildings. China is expected to experience a fivefold increase (from 5% to 28%), Brazil a sixfold increase (from 6% to 36%), South Africa a threefold increase, and India an increase of 2.5 times.25 A higher market demand results in a higher resale value and asset value, and a growing number of studies have proven that green building actually increases a building’s asset value. In 2015, 707 property companies worldwide representing over 61,000 properties, with an asset value of US$2.3 trillion, reported on the sustainability of their operations as part of the Global Real Estate Sustainability Benchmark (GRESB), and they identified a 7% asset value increase in sustainable building.24 For investors and owners, the median payback window of a commercial 46

Miller et al.

Singh et al.

Agha-Hossein et al.

1

12

Kats et al.

Steemers and Manchanda

—

154

2

—

8

No. of buildings

Heerwagen and Hase

Romm and Browning

Reference

2013

2010

2010

2009

2003

2001

1994

Year

UK

UK and India

USA

USA

USA

USA

USA

Country

Table 3.3  Sample studies of productivity and green buildings23–27

Y

Y

Y

Y

Y

Y

6–16%

Increase in productivity

Y

Y

—

—

—

Y

15–25% absenteeism reduction

Occupancy well-being

Lighting, indoor air quality, noise, indoor temperature

—

—

—

—

View, plants, daylight

Lighting, building enclosure, HVAC system

Building attributes

Predicted impact of net zero building

building is eight years for a regular building; however, commercial buildings often change owners every five years, or sometimes even earlier. This has become a major obstacle of promoting green building in the commercial market. If the owners and investors realize a financial benefit and short payback window frame of less than eight years by building green, they would be encouraged to continue green building and achieve a more aggressive net zero energy goal in their next investment project. This would create a positive cycle, driving environmentally friendly decisions through the reward of increased asset value.

Indirect benefits of net zero building Labor force building The transition toward sustainable and low-carbon communities requires the development and deployment of a range of new and existing energy technologies, and many nations consider clean energy policies as strategic pathways to enhance national competitiveness in science and technology.29 While green technology and labels potentially increase the market value of a building, net zero buildings can also increase profits for stakeholders in the building and construction industry— including contractors, developers, designers, and vendors—since they can charge additional consulting/design fees or sell the building for a higher price than a nonenergy-efficient building. By integrating net zero energy technologies into their portfolio, contractors and designers could access opportunities to capitalize on their roles as early adopters and industry leaders, providing them with a head start to build relationships with other energy-efficient and clean energy businesses, therefore expanding their professional and social networks. Green economic development and job creation are important factors worldwide. Some countries have already passed legislation to stimulate green job growth and clean energy adoption, such as Germany and China, whereas others, such as the United States, have provided tax incentives at state and local levels to encourage green job market growth. There are three different types of green jobs: direct employment, indirect employment, and induced employment.30 Direct employment refers to jobs in the building and construction industry that directly relate to building and creating green technologies. Indirect employment refers to those jobs created in the upstream and downstream industries associated with the building and construction industry, such as suppliers, transporters, and recyclers. Induced employment considers the wide scope of employment enhanced through direct and indirect employment activities, such as providing food and other basic needs. We will now compare three of the most recent studies conducted in three different countries to illustrate the potential of green labor force building, focusing on direct employment, which is mainly associated with the building and construction industry. In the United States, researchers from Ohio State empirically investigated the impact of clean energy policies at the state and local levels in stimulating and maintaining green jobs in US metropolitan areas.29 They used a database published in 2008 by the US Conference of Mayors and Global Insight, which included 361 US metropolitan areas. Their empirical results suggest that both

48

Predicted impact of net zero building

state clean energy policy tools and local climate actions have moderate and positive effects on the number of green jobs,29 and the promotion of green technologies and energy efficiency goals influences the provision of new skills training opportunities for architects, engineers, and contractors. Among the major metropolitan areas for green job growth, California, Illinois, Massachusetts, and Washington State are some of the early adopters of the Architecture 2030 goal. Massachusetts formed the Zero Net Energy Building Task Force and outlined 44 policy recommendations for new and existing buildings to move Massachusetts toward zero net energy building construction by 2030. The official adoption of a net zero goal by a state government has a direct impact on local building codes and regulations. Furthermore, the enhanced and increased requirements of a building’s energy performance not only create training and continued education opportunities for design professionals, but also create a space for certain small consulting firms and contractors who have a niche specialty in net zero design and construction. Figure 3.2 shows the building energy code adoption status in the United States in 2016. Figures 3.3 and 3.4 show the employment status in the design and construction fields in 2016. There is a direct correlation between aggressive energy code adoption and employment concentration. In Germany, research supported by the German Federal Ministry for Environment, Nature Conservation and Nuclear Safety showed that a net employment increase compared to 2014 employment data, caused by the renewable energy expansion, will reach around 150,000 in 2030, with gross employment

Figure 3.2 Building energy code adoption, 201631

49

Predicted impact of net zero building Figure 3.3 Employment for design professionals, 201632

Figure 3.4 Employment for construction workers, 201632

increasing to 500,000–600,000 in 2030.33 Lehr et al. discovered under different scenarios that the promotion and expansion of renewable energy and related industry transformation exhibit positive net employment effects, and that these effects strongly depend on further growth of global markets and German renewable energy exports.31 They also recognized other research illustrating the opposite results: for instance, another German study showed an increase in the cost of the project, induced by the application of PV systems, which cannot be balanced.34 Additional research from Spain showed negative economic impacts as well.35

50

Predicted impact of net zero building

Lehre’s team argued the opposing result as being due to other research focusing only on the domestic market, whereas a more sensible consideration of exports and global markets helps to understand the dynamics of countries that have developed a renewable energy industry sector.31 In China, a team investigated the relationship between the green economy and green job growth between 2006 and 2010. They found the questions, issues, and conditions to be more complicated than they had originally speculated. Chinese mitigation policies in China’s power generation sector from 2006 to 2009 caused a total of 44,000 net job losses. The jobs lost were caused by a combination of the massive closing of small coal-fired units and a lower number of indirect jobs associated with renewables and new energy compared to large coal-fired units. However, as the share of renewable energy, which has an indirect impact on employment, increased in 2010, the policies from 2006 to 2010 actually resulted in 472,000 net job gains.36 In general, higher and more stringent building performance goals lead to a higher demand for highly skilled design and construction teams, which can result in many training opportunities. Moreover, the advanced green technologies implemented in net zero building will create new job opportunities.

Social-community building Buildings account for 40% of carbon emissions and more than 30% of energy consumption globally; super-energy-efficient buildings could provide other societal and community benefits beyond the direct energy and cost savings. Sustainable districts, or net zero districts, are not only gentler on the natural environment, but may also benefit the humans who inhabit them37 by helping to forge and cement neighborhoods and encourage healthy lifestyles. Based on the World Green Building Trends 2016 report produced by Dodge Data & Analytics mentioned earlier, “encouraging sustainable business practices” is the most important social reason for building sustainable and net zero buildings.8 In the survey, 58% of respondents rate this as one of their top two reasons. Respondents from the United States and United Kingdom gave high percentage ratings to this item, 74% and 72% respectively, while Saudi Arabian respondents only gave it 18%. In the same report, the second factor for building green was “creating a sense of community”; among the respondents, 51% of Indians, 33% of Chinese, and 32% of Saudi Arabians voted for this factor.8 In developing countries, the focus on net zero building is often associated with building new mega-sustainable cities. The idea of zero energy is not constrained to individual buildings; in some scenarios, it would be more practical to approach zero energy at larger scales. When individual buildings are tall or high-rise buildings have a high-intensity process load, achieving a zero energy goal within the individual building footprint becomes very difficult. Balancing these types of energy-intense buildings with other less energyintense buildings could make it possible to reduce the overall energy demand within a district. Meanwhile, considering net zero energy at a larger scale or community level could create an opportunity for district energy systems that exploit load diversity between buildings to access renewable energy sources in ways that may be impractical for individual buildings.38 For instance, large

51

Predicted impact of net zero building

office buildings have a high energy demand during the daytime while adjacent residential single-story or multi-story buildings reach their energy peak at night. Therefore, sharing and distributing the overall energy through a district system with a temporary storage function reduces the overall peak hour demand and energy consumption, resulting in a reduced demand for the equipment as well. In a net zero district or neighborhood, the district system has a diverse load profile. For instance, some buildings need heating while others require cooling; therefore, the capacity of the entire district system required to meet the overall energy demand could be smaller than the simple sum of the individual peak demand. An awareness of other buildings’ status and needs, as well as sharing the overall energy, could enhance a sense of sharing and community. A community and society built on a shared infrastructure could provide opportunities that constantly remind its citizens of the shared resources and commodities. Developing countries have more opportunities to build large new communities with this new approach, which could explain why creating a sense of community is the number one motivation for building green in developing countries.

Cultural-social shift: impact on community Regardless of the growth in demand for “green buildings,” there are obstacles for the net zero building movement. According to a study conducted by a team from the University of Bath, there is little correlation between the number of low or zero energy standards a country has and the number of zero energy buildings built within that country. This suggests that the existence of many standards does not imply greater application and use of a zero energy building design standard within a country.39 The slow adoption rate of zero energy practices in certain countries is not caused by insufficient building codes; instead, an important role is played by ideological barriers, which are rooted in the creation of ecological theory. Ecological theory was needed to break the taboo of modernity, where technology would lead to endless progress.40 Since 1960, the early environmental movement recognized the potential dangers of modern technology and materials and the new cycle of energy flow and management style. Many scholars have written about the tension existing between nature and technology and its impact on human health. One of the earliest and most influential books was Silent Spring by Rachel Carson, an American biologist, conservationist, and pioneer of the environmental movement. Published in 1962, her book criticized the use of modern pesticides and their detrimental impact on the environment, such as killing birds and fish and contaminating rivers and streams. In the United States, Silent Spring has become a rallying point for the new social movement and has brought the balance back to technology advancement and natural resource conservation. Carson’s book and its followers are partly responsible for the ecology movement since the 1960s; the book also started the debate on technology’s positive and negative impacts. The notion of saving our planet from endless scientific, chemical, or physical advancements, which destroy the natural balance, has become very popular and has been accepted and interpreted by many different social groups.

52

Predicted impact of net zero building

Today, sustainable buildings and environments have many different meanings. The energy efficiency movement cannot survive without a sustainable social-technological framework. Solely focusing on the technical aspect of energy efficiency will not work. Net zero building not only represents potential energy and resource conservation, it also symbolizes people’s lifestyle choices and a deep belief in the coexistence between technology and the natural ecosystem. Questions concerning net zero building and the market do not revolve around whether incentives will be insufficient for net zero building and energy conservation, but rather concern over the direction of the reasoning behind net zero building and the social-technical mindset. In particular, nature has been made an object of conquest by technology and science for thousands of years. Examples of this span from a manmade lake in ancient China to today’s ski resort in Abu Dhabi, Ski Dubai. Summer temperatures in Abu Dhabi can reach 55 °C; the average temperature difference between the inside of the ski area and outside is almost 55 °C. Some researchers calculated the annual energy consumption of Ski Dubai as being 525–915 MWh to maintain its inside temperature—maybe more, depending on the exact insulation used.41 Its average daytime energy consumption could be around 700 kWh per day, or 255 MWh per year, which could power 255,000 homes in the United States per year. As demonstrated above, the net zero label may carry certain taboos inherited from “green” products and technology. To overcome ideological and psychological barriers of net zero building, cultural and attitude shifts are required. Besides the negative psychological impediment, there are three major social and cultural barriers currently existing that have a negative impact on people’s decision to build net zero: “overdiscounting the future,” “ecocentrisim,” and “positive illusion.”42 Extensive research indicates that people often apply very high discount rates in their consumption behavior.43, 44, 45 For example, a homeowner may not fully follow information about potential long-term energy saving and other environmental conservation advantages, resulting in under-insulation of their house and failure to equip the home with energy-efficient appliances. This situation is typically not attributed to a lack of information, but is instead simply failure to calculate and then make decisions based on payback periods. Also, with about one in six Americans moving homes each year, and the average stay in a single home being six years,40 it is difficult for homeowners to imagine and make decisions based on a payback period of more than six years; they often place priority on technologies that will result in immediate gain. Regarding the barrier of “ecocentrisim,” people often make self-serving judgments.46, 47, 48 The fairness of a decision has different levels, where a decision that might seem fair at the individual level could be harmful to an aggregated community. For instance, living in the suburbs enables parents to provide an open space for their children and the elderly to access better air quality; however, the overall suburban sprawl has created tremendous economic, environmental, and psychological stress to society as a whole (see Chapter 4). The third barrier, “positive illusion,” indicates people’s unrealistically favorable outlook: they have the tendency to see themselves and this world in a better condition than they are right now.49, 50 They exaggerate the positive outcomes and future while tending to ignore short-term and immediate danger and harm. This is particularly

53

Predicted impact of net zero building

prevalent in the building and construction industry. Contrary to claims from the US Green Building Council and the World Green Building Council, in his 2016 book, Reinventing Green Building, Yudelson indicated that “LEED is failing to grow in the United States, its largest and most important market.” LEED accounts for 90% of the US green building market share, and its growth has flattened since 2010, with LEED losing support in both new construction and existing building certifications.51 One reason that Yudelson recognized as responsible for LEED’s failure is the notion that “idealists designed LEED, realists rule the market.” LEED continues to be a voluntary rating system created by a small group of environmental activists and progressives with an idealist agenda for a sustainable future. Focusing on a positive outcome does not generate enthusiasm for net zero building among developers or building owners when their concerns are immediate.

Conclusion Ultimately, for any technical revolution to succeed, we need a deeply rooted cultural and social movement or change. The success of the smartphone, for example, was driven and supported by society’s desire to exchange information freely and quickly without an authorized censorship system. For net zero building to become a mainstream practice, culture and attitude are the foundation and key for success.

Notes i Verified net zero buildings have a publicly stated goal of achieving net zero, and have demonstrated the evidence. ii Emerging net zero buildings have a publicly stated goal of achieving net zero, but have not yet demonstrated the evidence. iii Based on author’s calculation using data from the US Energy Information Administration.

References 1 Getting to Zero Status Update and List of Zero Energy Projects. New Building Institute. Accessed January 2, 2019. https://newbuildings.org/wp-content/ uploads/2018/01/GTZ_2018_List.pdf 2 Laski, Jonathan, and Victoria Burrows. From Thousands to Billions: Coordinated Action towards 100% Net Zero Carbon Buildings by 2050. World Green Building Council. Accessed January 2, 2019. www.worldgbc. org/sites/default/files/From%20Thousands%20To%20Billions%20 WorldGBC%20report_FINAL%20issue%20310517.compressed.pdf 3 “Share of new dwellings built according to national nZEB definition or better than nZEB.” ZEBRA 2020. Accessed January 2, 2019. www. zebra-monitoring.enerdata.eu/overall-building-activities/share-of-new-dwellingsin-residential-stock.html#share-of-new-dwellings-built-according-to-nationalnzeb-definition-or-better-than-nzeb.html 4 Pachauri, Rajendra K., Myles R. Allen, Vicente R. Barros, John Broome, Wolfgang Cramer, Renate Christ, John A. Church et al. Climate Change 2014: Synthesis Report. Contribution of Working Groups I, II and III to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. IPCC, 2014. 54

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5 Chaudhary, Archana and Poojia Thakur Mahroti. “$1.3 Trillion housing boom set to be India’s next growth driver,” May 8, 2017. Accessed January 2, 2019. www.bloomberg.com/news/articles/2017-05-08/-1-3-trillion-housingboom-set-to-be-india-s-next-growth-driver 6 “Buildings.” European Commission. Accessed January 2, 2019. https:// ec.europa.eu/energy/en/topics/energy-efficiency/buildings 7 “How much energy is consumed in U.S. residential and commercial buildings?” U.S Energy Information Administration. Accessed January 2, 2019. www.eia.gov/tools/faqs/faq.php?id=86&t=1 8 World Green Building Trends 2016. Dodge Data & Analytics. Accessed January 2, 2019. www.worldgbc.org/sites/default/files/World%20Green%20 Building%20Trends%202016%20SmartMarket%20Report%20FINAL-2.pdf 9 Kylili, Angeliki, and Paris A. Fokaides. “European smart cities: The role of zero energy buildings.” Sustainable Cities and Society 15 (2015): 86–95. 10 “Passive House requirements.” Passive House Institute. Accessed May 9, 2017. www.passiv.de/en/02_informations/02_passive-house-requirements/02_ passive-house-requirements.htm 11 Artola, I., K. Rademaekers, R. Williams, and J. Yearwood. Boosting Building Renovation: What Potential and Value for Europe? Policy Department A: Economic and Scientific Policy, European Parliament, 2016. 12 Ramesh, T., R. Prakash, and K. K. Shukla. “Life cycle approach in evaluating energy performance of residential buildings in Indian context.” Energy and Buildings 54 (2012): 259–265. 13 Raw, G. J., M. S. Roys, and C. Whitehead. “Sick building syndrome: Cleanliness is next to healthiness.” Indoor Air 3, no. 4 (1993): 237–245. 14 Joshi, Sumedha M. “The sick building syndrome.” Indian Journal of Occupational and Environmental Medicine 12, no. 2 (2008): 61. 15 Menzies, D., J. Pasztor, F. Nunes, J. Leduc, and C. H. Chan. “Effect of a new ventilation system on health and well-being of office workers.” Archives of Environmental Health: An International Journal 52, no. 5 (1997): 360–367. 16 Wargocki, P., D. P. Wyon, Y. K. Baik, G. Clausen, and P. O. Fanger. “Perceived air quality, sick building syndrome (SBS) symptoms and productivity in an office with two different pollution loads.” Indoor Air 9, no. 3 (1999): 165–179. 17 Fisk, W. J. “How IEQ affects health, productivity.” ASHRAE Journal 44,no. 5 (2002): 56. 18 Chan, T. The Impact of School Building Age on Pupil Achievement. Office of School Facilities Planning, Greenville School District, Greenville, SC, 1979. 19 Earthman, G. I., and L. Lemasters. “Where children learn: A discussion of how a facility affects learning.” Paper presented at the annual meeting of Virginia Educational Facility Planners, Blacksburg, VA, February 1998. 20 Phillips, R. “Educational Facility Age and the Academic Achievement of Upper Elementary School Students.” D.Ed. dissertation, University of Georgia, 1997. 21 Schneider, Mark. Do School Facilities Affect Academic Outcomes? National Clearinghouse for Educational Facilities, 2002. Accessed January 2, 2019. https://files.eric.ed.gov/fulltext/ED470979.pdf 55

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22 Ries, R., M. M. Bilec, N. M. Gokhan, and K. L. Needy. “The economic benefits of green buildings: a comprehensive case study.” The Engineering Economist 51, no. 3 (2006): 259–295. 23 Romm, J. J., and W. D. Browning. Greening the Building and the Bottom Line. Rocky Mountain Institute, 1994. Accessed January 2, 2019. http:// library.uniteddiversity.coop/Ecological_Building/Greening_the_Building_ and_the_Bottom_Line.pdf 24 Heerwagen, J., and B. Hase. “Building biophilia: Connecting people to nature in building design.” Environmental Design and Construction 3 (2001): 30–36. 25 Miller, N., D. Pogue, Q. Gough, and S. Davis. “Green buildings and productivity.” Journal of Sustainable Real Estate 1, no. 1 (2009): 65–89. 26 Singh, A., M. Syal, S. C. Grady, and S. Korkmaz. “Effects of green buildings on employee health and productivity.” American Journal of Public Health 100, no. 9 (2010): 1665–1668. 27 Steemers, K., and S. Manchanda. “Energy efficient design and occupant well-being: Case studies in the UK and India.” Building and Environment 45, no. 2 (2010): 270–278. 28 “Study finds global green building is expected to double by 2018.” Dodge Data & Analytics. Accessed January 2, 2019. www.construction.com/news/ study-finds-global-green-building-expected-to-double-2018-feb-2016 29 Yi, H. “Clean energy policies and green jobs: An evaluation of green jobs in US metropolitan areas.” Energy Policy 56 (2013): 644–652. 30 Wei, M., S. Patadia, and D. M. Kammen. “Putting renewables and energy efficiency to work: How many jobs can the clean energy industry generate in the US?” Energy Policy 38, no. 2 (2010): 919–931. 31 “Status of state energy code adoption.” US Department of Energy. Accessed January 2, 2019. www.energycodes.gov/status-state-energy-code-adoption 32 “May 2017 OES maps.” US Bureau of Labor Statistics. Accessed January 2, 2019. www.bls.gov/oes/current/map_changer.htm 33 Lehr, U., C. Lutz, and D. Edler. “Green jobs? Economic impacts of renewable energy in Germany.” Energy Policy 47, (2012): 358–364. 34 Frondel, M., N. Ritter, C. M. Schmidt, and C. Vance. “Economic impacts from the promotion of renewable energy technologies: The German experience.” Energy Policy 38, no. 8 (2010): 4048–4056. 35 Jara, R. M., J. R. R. Julián, and J. I. G. Bielsa. Study of the Effects on Employment of Public Aid to Renewable Energy Sources. Universidad Rey Juan Carlos, March 2009. Accessed January 2, 2019. www.westernenergyalliance.org/wpcontent/uploads/2009/05/spanishstudy.pdf 36 Cai, W., C. Wang, J. Chen, and S. Wang. “Green economy and green jobs: Myth or reality? The case of China’s power generation sector.” Energy 36, no. 10 (2011): 5994–6003. 37 Bouton, Shannon, David Newsome, and Jonathan Woetzel. “Building the cities of the future with green districts.” McKinsey & Company. Accessed January 2, 2019. www.mckinsey.com/business-functions/ sustainability-and-resource-productivity/our-insights/building-the-cities-ofthe-future-with-green-districts

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38 Polly, B., C. Kutscher, D. Macumber, M. Schott, S. Pless, B. Livingood, and O. Van Geet. From Zero Energy Buildings to Zero Energy Districts (no. NREL/ CP-5500-66292). National Renewable Energy Laboratory, 2016. 39 Williams, Joseph, Rachel Mitchell, Vesna Raicic, Marika Vellei, Graham Mustard, Amber Wismayer, Xunzhi Yin et al. “Less is more: A review of low energy standards and the urgent need for an international universal zero energy standard.” Journal of Building Engineering 6 (2016): 65–74. 40 Norwine, Jim. World after Climate Change and Culture-shift. Springer, 2016. 41 Shahbaz, Muhammad, Rashid Sbia, and Helmi Hamdi. The Environmental Cost of Skiing in the Desert? Evidence from Cointegration with Unknown Structural Breaks in UAE. MPRA Paper 48007, University Library of Munich, Germany, 2013, 1–42. 42 Hoffman, A. J., and R. Henn. “Overcoming the social and psychological barriers to green building.” Organization & Environment 21, no. 4 (2008): 390–419. 43 Gately, D. “Individual discount rates and the purchase and utilization of energy-using durables: Comment.” Bell Journal of Economics 11, no. 1 (1980): 373–374. 44 Levine, M. D., J. G. Koomey, J. E. McMahon, A. H. Sanstad, and E. Hirst. Energy Efficiency, Market Failures, and Government Policy (no. LBL--35376; ORNL/CON--383). Lawrence Berkeley Lab., CA and Oak Ridge National Lab., TN, 1994. 45 Malhotra, D., G. Loewenstein, and T. O’Donoghue. “Time discounting and time preference: A critical review.” Journal of Economic Literature 40, no. 2 (2002): 351–401. 46 Babcock, L., and G. Loewenstein. “Explaining bargaining impasse: The role of self-serving biases.” Journal of Economic Perspectives 11, no. 1 (1997): 109–126. 47 Neale, M. A., and M. H. Bazerman. “Negotiator cognition and rationality: A behavioral decision theory perspective.” Organizational Behavior and Human Decision Processes 51, no. 2 (1992): 157–175. 48 Yang, R. J., and P. X. Zou. “Stakeholder-associated risks and their interactions in complex green building projects: A social network model.” Building and Environment 73 (2014): 208–222. 49 Bodenhausen, G. V., G. P. Kramer, and K. Süsser. “Happiness and stereotypic thinking in social judgment.” Journal of Personality and Social Psychology 66, no. 4 (1994): 621. 50 Bazerman, M. H., D. A. Moore, and J. J. Gillespie. “The human mind as a barrier to wiser environmental agreements.” American Behavioral Scientist 42, no. 8 (1999): 1277–1300. 51 Yudelson, J. Reinventing Green Building: Why Certification Systems Aren’t Working and What We Can Do about It. New Society, 2016.

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Chapter 4

Unintended consequences of net zero building from a life cycle perspective

Net energy and its ecological economic origin This section, following the introduction from Chapter 2, explains the origin of the net energy concept. Within the built environment, the current term “net zero energy” is often used to describe the balance in the operating energy of the building. Other forms of energy use besides the operating energy—relating to the transport of building materials, manufacturing, construction, repair, and maintenance—are not counted. However, the original concept of “net energy,” as used in the field of ecological economics, has a very different meaning.1 In ecological economics, net energy relates to the whole life cycle energy accounting of an object or system, and includes all the stages mentioned above, instead of focusing on the operating/use phase alone.

Self-sustaining and self-organizing From the 1970s concept of net energy flow to the current definition of a net zero energy building, how far have we moved from its ecological origin? Howard Odum outlined the two principles of energy flow—energy hierarchy and selforganization—in his 1971 book Environment, Power and Society. The energy hierarchy is the fifth energy law that Odum proposed: “All systems are organized hierarchically. . . . Energy flows of the universe are organized in energy transformation hierarchies. Position in the energy hierarchy can be measured by the amount of available energy transformed to produce it.”2 A building or built environment can be viewed as a living thermodynamic organism following principles in the same way as any natural or organic organism. To optimize such energy flow and hierarchical organization, we refer to nature as an example, as it is the best method for documenting such a hierarchy. For instance, the pattern of a small center aggregating toward a larger center can be found in tree trunks, leaves, pinecone seeds, rivers, and even air bubbles. Biologists have also found that this specific pattern exists in the animal kingdom as well, such as in termite and ant nests (see Figure 4.1). Self-organization is where “the downstream products have less energy to feed back and amplify. In the competition among self-organizing processes, network designs that maximize empower will prevail.”2 Together, self-organization and hierarchy create a centralized hierarchical pattern in nature. Odum described

58

Unintended consequences of net zero building

Figure 4.1 Hierarchical organization in an ant nest

the common systematic development and growth pattern found in the ecosystem: “Systems converge the transformation products to centers spatially, they concentrate these flows so that the feedback out from the centers is concentrated enough to have a strong effect by spreading its useful work over the contributing area.”2 A typical example would be water and stream flow. When we examine maps of historical towns and cities across different cultures, regardless of location or environmental conditions, we find that the outputs of small neighborhood centers move towards larger district centers. These district centers then move towards even bigger city centers at the next level. Larger historical metropolitan cities might have multiple city centers, with each center having its associated convergence pattern (see Figure 4.2). This represents not only a principle of geography, but also the connection between spatial organization and energy hierarchies. Through such a self-organizing mechanism, the resources and materials in circulation between small and large centers produce optimized efficiency as a comprehensive system. When different parts of a city or town are brought together, the overall organization of the whole system is just as important to the system’s final performance—if not more—as the individual parts functioning alone. In this way, historic cities and towns function as an integrated living system, and energy and materials can be distributed and circulated on an as-needed basis. In the early development of green building and solar houses, we mainly focused on passive design strategies: the way in which design follows the energy flow hierarchy and maximum power principle.i

59

Unintended consequences of net zero building Figure 4.2 Map of Lucca city (Google Earth, 2018)3

This ecological principle and systematic thinking of sustainable building has undergone several changes, starting in 2000. Attention has focused on technologies, advanced building materials, and end-energy usage. This isolated attention and heavy dependency on individual products or advanced building systems was indeed a method to defy the ecological origin and principles of net zero. Despite a higher interest in integrated design and construction and interactions between different building systems, energy flow and building performance have been confined within the individual building boundary and operational phase. In the energy flow equation of the natural ecosystem, all systems and individual components depend on solar energy as their primary source, and the productivity of the system depends on the energy captured by the producer, such as a leaf or flower petal. Basically, energy flows in large and connected open systems to produce maximum efficiency. However, in the current net zero building practice, energy flows in a closed loop, which may be extremely large, inefficient, and energy intense. The energy consumed by a building or group of buildings flows from power plants that may be located 1000 from the building site. While the international trade network has made delivering building materials and components globally possible, advanced buildings materials, assemblies, and components are not readily available in all locations. Most new buildings must import those components from far away. For instance, a high-rise building built in Abu Dhabi may have curtainwall glass processed and manufactured in China, stone processed and manufactured in the United States, and mechanical equipment from Germany. The heavy dependency on advanced synthetic building materials imported from outside the local ecosystem does create the possibility to achieve the mathematical net zero goal

60

Unintended consequences of net zero building

(end energy use). However, the separation between “onsite” producers and remote “imported” energy results in a much lower sustainability index. Consequently, this will not produce a true net energy flow according to its ecological definition. The same concept has also dominated urban design and planning over the past 20 years. Instead of a self-organized, optimized shape following the energy flow as traditional towns and villages do, modern city developments have heavily relied on planned utility grids. Often, we experience growth without pattern, and growth with sprawl has proved to be very inefficient.

Divergence and deviation: renewable energy is not free In current practice, design professionals treat renewable energy as free. However, renewable energy sources that exist in the natural ecosystem are far from “free” and “unlimited.” Natural “technologies” employed in nature were developed and perfected based on millions of years of wisdom, such as selfregulating leaves to control evaporation or the ability of plants to track the sun.4 Crucial factors related to renewable energy are often ignored, including the cost of renewable energy sources and their capacity to supply either electricity or other liquid fuels to the entire world economy. Additionally, losses due to energy conversion, storage, and transport also need to be considered. From an ecological perspective, renewable resources are simply different kinds of energy inputs with shorter renewal frequencies.5 Research by F. E. Trainer found that renewable energy sources will not be able to sustain present rich-world levels of energy use, and that a sustainable world order must be based on the acceptance of much lower per capita levels of energy use and living standards as well as a zero-growth economy.6 According to the World Bank’s data, from 1975 to 2010 worldwide energy consumption per capita increased 46%, and the trend is expected to continue (see Figure 4.3).

Figure 4.3 Energy use (equivalent to a kg of oil per capita) adapted from World Bank data1

61

Unintended consequences of net zero building

This will eventually deplete all available natural and renewable energy resources. Only through a decrease in energy consumption can we sustain a growing population and energy-intense lifestyle. An increase in electricity production efficiency should be accompanied by a decrease in overall consumption. Most current net zero energy definitions and design guidelines have not distinguished between high-energy consumption buildings with high renewable energy production and low-energy buildings with reduced renewable energy substitution. Their only concerns are whether a renewable energy source meets the immediate demands for building operation, maintenance, and/or construction.7

Unintended consequence one: environmental impact associated with embodied energy Missing embodied energy Most net zero building focuses on new construction instead of renovating existing buildings. This might be due to the public’s perception that retrofitting existing buildings is difficult and uncommon, as well a lack of awareness and knowledge about embodied energy. Embodied energy (EE) is defined as the total energy input consumed throughout a product’s life cycle. Initial embodied energy represents the energy used for the extraction of raw materials, transportation to the factory, processing and manufacturing, transportation to site, and construction. Once the material is installed, recurring embodied energy represents the energy used to maintain, replace, and recycle materials and components of a building throughout its life. The architectural and engineering professions continue to drive down operational energy levels of buildings through initiatives like the AIA 2030 Commitment. This places greater importance on the energy embodied in the building’s materials, which represents a percentage of a building’s total energy footprint. Academic studies have illustrated that embodied energy accounts for most of a building’s energy footprint for approximately the first 15 to 20 years of a building’s life cycle. The amount of embodied energy in a building depends on the material resources—the origin of construction materials, distance to transport raw materials to the manufacturer, and method for extracting the raw materials. Unfortunately, this area of research has been largely ignored in the current adopted net zero energy building calculation. To date, no country has code requirements regarding embodied energy requirements for buildings.8 Several sustainable building rating systems include certain requirements for taking the environmental impact of building materials into consideration, such as LEED and the Living Building Challenge. However, in a study by Marszal et al., only two of 12 net zero energy building definitions include embodied energy in the primary energy balance.7 The concept of incorporating embodied impacts in the net zero building design process is particularly important because the typical net zero energy and net zero emission concepts used in North America and Asia have only focused on the energy used during the operational stage. This omits implications that arise over the full life cycle,8 and the omission of the importance of embodied energy could create misleading results from net zero energy calculations.

62

Unintended consequences of net zero building

The annual embodied energy (AEE) will always be above zero since resources and energy are required to construct a building. Therefore, to balance the embodied energy, the energy used in the operational phase of a building must be below zero to meet the life cycle zero energy building goal. To achieve an annual operational energy use (AOE) of less than zero, net positive building is needed, as net zero operational energy use alone is not sufficient. To remain in operation, the building must produce more energy than is consumed, which often involves installation of some form of renewable energy technology, such as solar panels, wind turbines, or geothermal wells. Since these options are not without charge, they must be considered as building components, where their additional embodied energy is annualized and entered into the equation as a part of the annual embodied energy.1 Enlarging building components or renewable energy systems with the sole intention of bringing the operational energy to zero could result in a high increase of embodied energy, meaning that the total annualized life cycle energy (ALCE) might not significantly decrease, or could even increase.1 Table 4.1 presents studies on the relation between embodied energy and overall life cycle energy consumption. Embracing the embodied energy in the current green building code and rating system is gaining importance as in 20 years, the majority of buildings in developing countries will reach the end of their service life. In developing countries like China, the average life span of a building, typically 30 years, is shorter than in developed countries. With such a short turnaround rate—half of developed countries will reach the end of service life in the near future—understanding the full benefit of net zero building will facilitate decision-makers in making the correct decisions.

Is new always better? Sara Wilkinson indicates that over time, the original function of any building diminishes: “Four types of obsolescence take form: physical obsolescence, functional obsolescence, economic obsolescence, and locational obsolescence.”25 In fact, obsolescence can affect a building at any location any time during its life cycle, and building users must adapt the building to every changing condition. Ultimately, as Wilkinson says, all buildings will eventually become obsolete and will require modification to adapt to changes due to environmental, functional, locational, and economic conditions. Then the question becomes: which is better—constructing new buildings or retrofitting the old? The answer lies in the understanding of embodied energy. Embodied energy has three different phases, including initial and recurring embodied energy, which were described earlier. The third phase, demolition energy, includes all the energy used to deconstruct a building, transport and process the debris, and dispose of or recycle the used building assemblies. When the decision is made to raze an existing building and build anew, the entire embodied energy of the existing building will likely be lost. Accordingly, the benefits of retrofitting existing buildings have captured the attention of many academics, and a large number of studies have focused on the comparison of different options, including adaptive reuse. However, only a handful of countries have taken serious actions towards promoting adaptive reuse and energy

63

9

Peuportier

12

2002

2002

2006

4

60

Marceau et al.14

Thormark15

2010

2013

2014

2016

2018

Gustavsson and Joelsson20

Stephan and Crawford21

Stephan and Stephan22

Chasta et al.23

Kristjansdottir et al.

24

Italy

2009

Blengini19

Norway

15 countries

Lebanon

Belgium

Sweden

Israel

2008

China

2008

Huberman and Pearmutter18

9 countries

Sweden

USA

Australia

Sweden

Xing and Jun17

Sartori and Hestnes

16

2001

2001

France

2001

4

Australia

2001

4

USA

Country

2001

Date

1

Case study no.

Morrissey and Horne13

Adalberth et al.

11

10

Treloar et al.

Keoleian et al.

Reference

2

60–75%

11–74%

18%

23%

45–60%

7%

60%

9–46% (for low-energy buildings) 2–38% (for conventional buildings)

45%

Y

Y

10–30%

10–15%

10.7 GJ/m for three stories

Y

Embodied energy only

2

—

—

800–1600 GJ/m2/year

Residential

Residential

Residential

Residential

Residential

7500–11,500 KWh/m /year 800–1600 GJ/m2/year

Residential 2

—

Residential

Residential

—

—

—

—

Residential

Residential

Residential

Type of building

999 MJ/m2/year

Y

—

Y

14,913 GJ

Y

Y

6100–9100 kWh/m

Y

Y

Y

Life cycle energy

Table 4.1  Research and studies related to embodied energy and life cycle energy consumption of buildings

8

45

50

100

50

40

50

50

—

50

100

 30–75

50

80

40

50

Life span

Unintended consequences of net zero building

retrofitting of existing buildings. For instance, in the United Kingdom, more work is undertaken on adaptation than on new building.26, 27 The high proportion and amount of annual expenditure on building adaption in the UK and several other developed countries demonstrate the importance of adaptation to business and commerce. However, these countries only represent a small percentage. Most developed countries have a large stock of older buildings. For instance, in the EU, existing buildings are characterized by an average age of about 55 years. Old buildings are less energy-efficient and close to the end of their life stage, requiring decisions to be made and standards to be drawn up. The European Commission carried out a study to determine refurbishment rates in the EU, with the results indicating 1.2% for Northwestern Europe, 0.9% in Southern Europe, and 0.5% for new member states.28 The low overall retrofit and renovation rate prompts industry and government to adopt retrofitting existing buildings as an acceptable solution for a carbon-neutral future. Adaptive reuse and conservation are frequently discussed in terms of economic, cultural, and design values. Not only do existing historical buildings have cultural and historical significance, but preservationists also believe that such buildings carry environmental impact reduction benefits. For instance, a report published by the Preservation Green Lab of the US National Trust for Historic Preservation included several relevant findings. In particular, the authors concluded: Significantly, even if it is assumed that a new building will operate at 30 percent greater efficiency than an existing building, it can take between 10 and 80 years for a new, energy-efficient building to overcome the climate change impacts that were created during construction.29

Net zero building as an elite pursuit (high-cost and high-tech) Since high-performing net zero buildings have not been embraced as mainstream, assumptions have spread that these buildings must be technically difficult and not solid financial investments.30 Meanwhile, much ambiguity and uncertainty exist in realizing net zero on a large scale, such as which system of measurement to use— primary energy or carbon emissions—and what technologies should be deployed and made available? The lack of systematic discussion and clear conclusions has resulted in incorrect perceptions and market confusion, eventually stalling net zero’s momentum. Net zero building has often been associated with a high initial cost and sophisticated design and operational systems, which has created psychological barriers to the public promotion of net zero building, especially in developing countries. As will be described further in Chapter 5, the premium cost of green and net zero buildings is still being debated. Consequently, the widespread perception of high cost could impede the development of net zero buildings in developing countries. In China, between 2003 to 2014 construction revenue increased from US$109 billion to US$2568 billion, with an annual growth rate of 30.12%.31 Certain researchers predict the urbanization rate in China will reach 70% by 2050,32 which projects significant new construction growth. As the growth and construction continue, a major challenge encountered by the Chinese construction industry

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Unintended consequences of net zero building

is becoming more apparent: environmental impact. The severe environmental consequences due to smog and pollution are visible results of rapid urbanization and unsustainable construction practices. However, there are more critical concerns—often hidden from public eyes—namely, the enormous depletion of resources, massive construction waste, safety risks to construction workers, and occupancy. In 2014, the central government issued a policy, China’s New-Style Urbanization Plan, for 2014 to 2020, with the aim to pursue a more sustainable and qualitative growth. This plan has three areas of focus: green cities, smart cities, and cultural cities. Clearly, the focus of China’s construction industry growth has shifted from a quantitative approach to a qualitative approach. A resulting problem of the construction boom was that developing countries did not have standard sustainable practices during their peak period of construction development. When the speed of regulation lags behind development pace, it results in a large portion of new buildings that do not meet sustainable design requirements nor the net zero energy goal. One solution that has been implemented is for developing countries to adopt energy efficiency codes and policies from Western developed countries while also developing their own codes. In the 1990s, the concept of sustainable design was introduced to the Chinese building and construction industry.33 In the following ten years, the central government and its associated research institution and design agency slowly developed a green building evaluation system based on multiple Western standards that was suitable for Chinese conditions. The first sustainable design regulation, “Assessment Standard for Green Building,” was published in 2006. Later, the “Design Standard for Green Building” for Beijing was published in 2012. Since these regulations and building codes were modeled on Western standards, they naturally inherited the shortcomings of those models as well: for instance, the perception of green and net zero building being costly and of net zero building being only suitable for wealthy clients and special types of buildings. Compared to Western developed countries, the awareness and formation of sustainable design practice has come much later in developing countries, like China and India, and in the next decades those countries will play a deterministic role in achieving the net zero goal. The main challenge of sustainable building in China and other developing countries, according to multiple surveys, is the higher cost, with more than 60% of respondents for one survey identifying green building as being expensive and only for a particular group of clients.34 These misperceptions associated with pursuing net zero building, mainly the idea of their being elite projects requiring large budgets, creates the wrong expression that net zero building is merely a technological challenge rather than a social-technical paradigm shift.

Unintended consequence two: societal impact—more suburban sprawl and a green lifestyle? Low-density development New single-family detached houses are an easy target for net zero energy building. Currently, the most commonly employed renewable energy technology is still the photovoltaic panel, and production of electricity heavily relies on the amount of solar

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Unintended consequences of net zero building

radiation and total roof area that can receive and collect solar energy. Building with a large footprint but fewer levels certainly presents the best candidate; furthermore, this type of building leads to low-density development. One place with low-density development is a suburb. People are attracted to suburbia for its bigger lots, quieter neighborhoods, and the idea of being close to nature. However, merely being surrounded by green does not translate to sustainable and healthy living. Several studies have revealed that the carbon footprint of a suburban neighborhood is much higher than that of a dense urban block. Norman et al. studied two cases in the city of Toronto, and the results indicated that, compared to a high-density urban core development, a low-density suburban development has a higher intensity of energy and greenhouse gas emissions, by a factor of 2–2.4, on a per capita basis. Moreover, the research also recognized that, despite a comparatively low transit ridership for the low-density case, normalized transit energy use/GHG emissions are higher in a low-density context, which is likely due to the greater travel distances required and heavy reliance on diesel buses instead of streetcars and subways.35 A suburban house has a larger footprint and a less compact building envelope, and consumes more energy on heating and cooling per capita. Additionally, most suburban dwellers use automobiles as their daily commute method. Overall, low density and a large building footprint together create a very wasteful development pattern. James Howard Kunstler called suburbia “the greatest misallocation of resources in the history of the world.”36 In historical towns, following the law of thermal dynamic flow, the layout tends to have a hierarchical fractal-like pattern that helps create the most efficient energy flow without waste, and all-important public spaces act as subcenters that connect to one another. However, sprawling suburbia is based on a monolithic design principle, where low-density buildings stretch without a coherent or comprehensively derived pattern and are not connected to others. There are many societal impacts associated with suburban living, such as political fragmentation, declining quality of community life, lack of affordable housing, and social isolation. The widespread suburban sprawl has been viewed as an erosion of civic engagement and mutual trust—a loss of “social capital,” which has been studied extensively by professionals and research groups from different fields. Several researchers have clearly attributed the decline of social capital in part to suburban sprawl.37, 38 A number of forces could influence change on the unsustainable and soulless monotony of the modern suburbs, with energy related to financial costs at the top. More precisely, large households are associated with rising utility bills, and lengthy commutes not only result in increased fuel consumption and high carbon emissions, but also increase individuals’ stress due to traffic jams. Despite the above consequences, the preference for suburban living has not faded yet. Three demographic groups that shape the current and future market are the Baby Boomers, Generation Y, and Millennials, and their choice of primary residence will determine the fate of the suburbs in the next ten years. Survey results from AARP (formerly the American Association of Retired Persons) in 2010 indicate that 85% of the age group 45 and over preferred to stay in their existing suburban home.39 The Urban Land Institute found that Generation Y preferred to spend less on houses on urbanizing commercial nodes along transit routes convenient

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to city centers, namely urban-suburban centers. Based on a small sample survey the author conducted, 65% of Millennials who live in suburban areas actually prefer to live in the suburbs, which differs from most stereotypes associated with Millennial home buyers. The trend of further development of suburbs most likely will continue. Meanwhile, the benefit of living close to nature and an unobstructed opportunity to install solar panels on roofs has painted an unjustified green picture of suburban living, which could indirectly promote suburban sprawl.

Potential solution: eco-districts—green urbanism with an integrated framework In order to shift the generations’ rosy view of suburbia living as being a lifestyle close to nature, an ecological perspective is needed to further examine suburban living. As mentioned in Chapter 3, the concept of zero energy is not restricted to individual buildings40 and has already been extended to campus, district, neighborhood, and city levels. In dense urban areas, due to buildings having a high volume (height) to floorspace ratio, there is not adequate roof area for PV panels that can produce enough electricity for an entire building. The amount of renewable energy available within the building footprint is limited as well. Meeting the net zero energy goal for an individual building becomes very challenging. Instead, approaching zero energy on a larger scale can provide opportunities for district energy systems to exploit load diversity between buildings and access renewable energy sources in ways that may be impractical for individual buildings.15 These so-called eco-districts present the optimal scale to accelerate sustainability to achieve net zero energy targets for buildings in urban settings with more constraints, and these cities will move from their current eco-districts to net energy districts over time. Examples of eco-districts include the Upton development in Northampton, England, Civano in Arizona, the United States, Gothenburg in Sweden as a super sustainable city, and Songdo in South Korea as a new ecocity. One of the leading researchers of the net zero movement, Paul Torcellini, stated that a “net zero community makes more sense.”41 Certain efforts have been made to achieve the net zero goal at the district level. At the University of California, Davis campus, a zero energy goal was pursued in the West Village development. The buildings together can achieve an energy balance at the annual level, which required a high-density, mixed-use development. UC Davis West Village campus occupies 52 hectares and provides housing for about 3000 people. The net zero campus project was supported by the Department of Energy with a $2.5 million fund. As of 2017, more than 2000 students, faculty, and staff live in West Village. The project includes 663 apartments, 475 single-family homes, 3948 m2 of retail space, a recreation center, and other facilities.42 Since the 2000s, there have been several high-profile policy initiatives at the global level to promote sustainable development, urban resilience, and eco-city creation (see Table 4.2). These eco-district, eco-city, and smart-city development initiatives will create considerably different growth patterns that can combat the suburban sprawl while increasing people’s life quality. Chapter 8 will take readers through detailed information on eco-district developments and related benefits.

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Table 4.2  Global initiatives to promote sustainable city development Initiative

Year

No. of cities involved

United States

Clinton Foundation’s 100 Resilient Cities43

2013

100

European Commission

Eco-city project44

2005–2012

  3

Global

SlimCity45

n/a

n/a

China

New-Style Urbanization Plan

2014–2020

Entire country

India

100 Smart Cities Mission

2017–2022

100

Japan

Top Eco-City Contest47

2001–present

n/a

Korea

Ubiquitous Eco-City Planning Initiative48

2008–present

40+

46

Unintended consequence three: ecological degradation The third unintended consequence is closely related to the previous two unintended consequences. There are two misleading concepts of net zero building that may have ecological and environmental impacts. The first is the sole focus on the operating energy. The net zero approach is generally viewed as a design method for balancing resources drawn from the natural ecosystem, such as energy and water, and the overall consumption of resources within a particular boundary over a specified time period. More precisely, net zero building produces the same amount of energy onsite from a renewable source as that consumed by the building. The idea of incorporating embodied energy in the net zero building design and calculation is particularly important since most current net zero building only focuses on the operating energy that will be consumed onsite and its associated environmental impact. The environmental impact and energy consumption caused by the production of materials, building construction, maintenance, and end of life are not included as part of the zero balance, although several green building rating systems have begun to show interest. Globally, most building regulations and codes have focused on building energy consumption, with insufficient practical guidance for design professionals about the environmental impact caused by buildings, which can lead to miscalculations. It is possible for a net zero energy building design solution to have a considerably high environmental impact due to the building materials and construction methods that have been selected.49 For example, Middle Eastern countries rely heavily on foreign companies to supply the curtain wall for most of their high-rise buildings. The energy-intensive manufacturing process occurs outside the property boundaries, thus the transportation/shipping energy is often neglected. A net zero energy glass building in those extreme conditions may still be possible, simply because the client can have many solar panels installed on the building, generating electricity to offset the energy consumed. The second misleading concept is the fact that people regard renewable energy as “free,” as mentioned earlier. Even though solar energy itself is free,

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Unintended consequences of net zero building

it requires the purchase of materials and energy to harvest its energy, with the most popular device being the solar panel. To produce solar panels, we must extract raw materials that are then processed into different types of solar cells using energy. The solar cell manufacturing process also involves several hazardous materials that contain the same types of chemical compounds used in the general semiconductor industry, such as hydrochloric acid, sulfuric acid, and nitric acid. These hazardous materials pose a danger to workers, and the chemicals will eventually be released back into the environment.50 As thin-film solar cells become more popular due to their flexibility, awareness is needed of the potential environmental damage associated with the toxic materials in those cells.

Conclusion Innovative design approaches and advanced technology aim to serve humanity. There is no question that energy-efficient appliances, cars, and lighting fixtures help to conserve energy. Conversely, the high gas mileage of automobiles could indirectly encourage people to drive longer distances if its cost is cheap. Detached single-family houses that are one-story, car-dependent, solar panel-equipped, and scattered over a large area might have a higher chance of achieving the net zero energy balance. But they require enormous quantities of gasoline for residents to commute between work and home, as well as considerable embodied energy per house to construct, maintain, and repair, causing damage to large areas of land. Furthermore, even with energy-efficient appliances, mechanical systems, and high insulation, these scattered and detached houses lose heat and coolness to the surrounding air because they do not share walls, floors, or roofs with other structures. These unintended consequences described above are connected to the building industry’s tendency to treat buildings as individual and independent developments. The current approach to achieve net zero energy heavily depends on advanced technology and highly controlled building systems, which creates huge financial and technological barriers for many less resourceful projects and building owners. Meanwhile, zoning and planning guidelines do not provide clear directions on how the performance of individual buildings should be assessed based on their impact on surrounding areas or as part of a large urban scale. The limited attempts to create net zero communities and campuses have hindered bridging the gap between individual building performance and city-wide sustainability. Understanding the natural environment and human society as one holistic system means viewing parts, processes, and connections as the foundation for all building design types. If we trace the origin of net zero energy back to its ecological roots, we can consider net zero building as a guiding design principle for all buildings and a professional ethic for all practitioners. Consequently, it must be perceived as a core consideration, and not as an add-on item.

Note i The maximum power principle is the fourth principle of energy introduced by Alfred Lotka and later developed by Howard T. Odum.

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References 1 Hernandez, Patxi, and Paul Kenny. “From net energy to zero energy buildings: Defining life cycle zero energy buildings (LC-ZEB).” Energy and Buildings 42, no. 6 (2010): 815–821. 2 Odum, Howard T. Environment, Power and Society. Wiley-Interscience, 1971. 3 Google Earth 7.1. 2018. Lucca, Italy 43°50’31.34”N, 10°30’13.72”E, elevation 60 m. 3D map, buildings data layer. Accessed January 2, 2019. www. google.com/earth/index.html 4 Berggren, Björn, Monika Hall, and Maria Wall. “LCE analysis of buildings— taking the step towards net zero energy buildings.” Energy and Buildings 62 (2013): 381–391. 5 Yi, Hwang, Ravi S. Srinivasan, William W. Braham, and David R. Tilley. “An ecological understanding of net-zero energy building: Evaluation of sustainability based on emergy theory.” Journal of Cleaner Production 143 (2017): 654–671. 6 Trainer, F. E. “Can renewable energy sources sustain affluent society?” Energy Policy 23, no. 12 (1995): 1009–1026. 7 Marszal, Anna Joanna, Per Heiselberg, Julien S. Bourrelle, Eike Musall, Karsten Voss, Igor Sartori, and Assunta Napolitano. “Zero energy building— a review of definitions and calculation methodologies.” Energy and Buildings 43, no. 4 (2011): 971–979. 8 Lützkendorf, Thomas, Greg Foliente, Maria Balouktsi, and Aoife Houlihan Wiberg. “Net-zero buildings: incorporating embodied impacts.” Building Research & Information 43, no. 1 (2015): 62–81. 9 Keoleian, G. A., S. Blanchard, and P. Reppe. “Life-cycle energy, costs, and strategies for improving a single-family house.” Journal of Industrial Ecology 4, no. 2 (2000): 135–156. 10 Treloar, G., F. Fay, B. Ilozor, and P. Love. “Building materials selection: greenhouse strategies for built facilities.” Facilities 19, no. 3/4 (2001): 139–150. 11 Peuportier, B. L. P. “Life cycle assessment applied to the comparative evaluation of single family houses in the French context.” Energy and Buildings 33, no. 5 (2001): 443–450. 12 Adalberth, K., A. Almgren, and E. H. Petersen. “Life cycle assessment of four multi-family buildings.” International Journal of Low Energy and Sustainable Buildings 2 (2001): 1–21. 13 Morrissey, J., and R. E. Horne. “Life cycle cost implications of energy efficiency measures in new residential buildings.” Energy and Buildings 43, no. 4 (2011): 915–924. 14 Marceau, M. L., J. Gajda, M. G. VanGeem, T. Gentry, and M. A. Nisbet. Partial Environmental Life Cycle Inventory of an Insulating Concrete Form House Compared to a Wood Frame House. Portland Cement Association, 2002. PCA R&D Serial No. 2464. 15 Thormark, C. “A low energy building in a life cycle—its embodied energy, energy need for operation and recycling potential.” Building and Environment 37, no. 4 (2002): 429–435.

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16 Sartori, I., and A. G. Hestnes. “Energy use in the life cycle of conventional and low-energy buildings: A review article.” Energy and Buildings 39, 3 (2007): 249–257. 17 Xing, S., Z. Xu, and G. Jun. “Inventory analysis of LCA on steel- and concrete-construction office buildings.” Energy and Buildings 40, no. 7 (2008): 1188–1193. 18 Huberman, N., and D. Pearlmutter. “A life-cycle energy analysis of building materials in the Negev Desert.” Energy and Buildings 40 no. 5 (2008): 837–848. 19 Blengini, G. A., “Life cycle of buildings, demolition and recycling potential: A case study in Turin, Italy.” Building and Environment 44 (2009): 319–330. 20 Gustavsson, L., and A. Joelsson. “Life cycle primary energy analysis of residential buildings.” Energy and Buildings 2 (2010): 210–220. 21 Stephan, A., and R. H. Crawford. “A multi-scale life-cycle energy and greenhouse-gas emissions analysis model for residential buildings.” Architectural Science Review 57 (2014): 39–48. 22 Stephan, A., and L. Stephan. “Reducing the total life cycle energy demand of recent residential buildings in Lebanon.” Energy 74 (2014): 618–637. 23 Chastas, Panagiotis, Theodoros Theodosiou, and Dimitrios Bikas. “Embodied energy in residential buildings-towards the nearly zero energy building: A literature review.” Building and Environment 105 (2016): 267–282. 24 Kristjansdottir, Torhildur Fjola, Niko Heeren, Inger Andresen, and Helge Brattebø. “Comparative emission analysis of low-energy and zero-emission buildings.” Building Research & Information 46, no. 4 (2018): 367–382. 25 Wilkinson, Sara J., Hilde Remøy, and Craig Langston. Sustainable Building Adaptation : Innovations in Decision-making. Wiley-Blackwell, 2014. 26 Egbu, C. O. “Refurbishment management: Challenges and opportunities.” Building Research and Information 25, no. 6 (1997): 338–347. 27 Ball, R. M. “Reuse potential and vacant industrial premises: Resisting the regeneration issue in Stoke on Trent.” Journal of Property Research 19 (2002): 93–110. 28 Eichhammer, Wolfgang, Tobias Fleiter, Barbara Schlomann, Stefano Faberi, Michela Fioretto, Nicola Piccioni, Stefan Lechtenböhmer, Andreas Schüring, and Gustav Resch. Study on the Energy Savings Potentials in EU Member States, Candidate Countries and EEA Countries: Final Report. FraunhoferInstitute for Systems and Innovation Research, 2009. Accessed January 2, 2019. https://ec.europa.eu/energy/sites/ener/files/documents/2009_03_15_ esd_efficiency_potentials_final_report.pdf 29 The Greenest Building: Quantifying the Environmental Value of Building Reuse. National Trust for Historic Preservation, 2011. Accessed January 2, 2019. https:// living-future.org/wp-content/uploads/2016/11/The_Greenest_Building.pdf 30 “Every building on the planet must be ‘net zero carbon’ by 2050 to keep global warming below 2°C—new report.” World Green Building Council, May 31, 2017. Accessed January 2, 2019. www.worldgbc.org/news-media/ every-building-planet-must-be-%E2%80%98net-zero-carbon%E2%80%992050-keep-global-warming-below-2%C2%B0c-new

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31 Ji, Yingbo, Fadong Zhu, Hong Xian Li, and Mohamed Al-Hussein. “Construction industrialization in China: Current profile and the prediction.” Applied Sciences 7, no. 2 (2017): 180. 32 Wang, Yilei, Qinghua Zhu, and Yong Geng. “Trajectory and driving factors for GHG emissions in the Chinese cement industry.” Journal of Cleaner Production 53 (2013): 252–260. 33 Yuejun, Xiao, and Qiao Zhichun. “The problems and countermeasures for implementing green building in China.” Paper presented at International Conference on Information Management, Innovation Management and Industrial Engineering, 2009, 114–118. 34 Bunz, Kimberly R., Gregor P. Henze, and Dale K. Tiller. “Survey of sustainable building design practices in North America, Europe, and Asia.” Journal of Architectural Engineering 12, no. 1 (2006): 33–62. 35 Norman, Jonathan, Heather L. MacLean, and Christopher A. Kennedy. “Comparing high and low residential density: Life-cycle analysis of energy use and greenhouse gas emissions.” Journal of Urban Planning and Development 132, no. 1 (2006): 10–21. 36 Kunstler, James Howard. The Long Emergency: Surviving the End of Oil, Climate Change, and Other Converging Catastrophes of the Twenty-first Century. Grove Press. 2006. 37 Moe, Richard, and Carter Wilkie. Changing Places: Rebuilding Community in the Age of Sprawl. Henry Holt & Company, 1997. 38 Calthorpe, Peter. The Next American Metropolis: Ecology, Community, and the American Dream. Princeton Architectural Press, 1993. 39 Keenan, Teresa A. Home and Community Preferences of the 45+ Population. AARP Research Center, September 2014. Accessed January 2, 2019. www.aarp.org/content/dam/aarp/research/surveys_statistics/il/2015/homecommunity-preferences.doi.10.26419%252Fres.00105.001.pdf 40 Polly, Ben, Chuck Kutscher, Dan Macumber, Marjorie Schott, Shanti Pless, Bill Livingood, and Otto Van Geet. From Zero Energy Buildings to Zero Energy Districts (no. NREL/CP-5500-66292). National Renewable Energy Laboratory, 2016. 41 Torcellini, Paul (Principal Engineer) in discussion with author, November 2017. 42 “UC Davis West Village: A UC Davis planned zero net energy neighborhood.” UCDAVIS. Accessed January 2, 2019. https://westvillage.ucdavis.edu/ 43 “100 Resilient Cities Centennial Challenge.” Clinton Foundation. Accessed January 2, 2019. www.clintonfoundation.org/clinton-global-initiative/commit ments/100-resilient-cities-centennial-challenge 44 “Joint eco-city development in Scandinavia and Spain.” Eco-City Project. Accessed January 2, 2019. www.ecocity-project.eu/ 4 5 “SlimCity.” Arup Foresight. Accessed January 2, 2019. www.driversofchange. com/projects/slimcity/ 46 “Smart Cities Mission.” Ministry of Housing and Urban Affairs, Government of India. Accessed January 2, 2019. http://smartcities.gov.in/content/

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47 “Japan’s top eco-city contest providing a path to a sustainable community.” Japan for Sustainability. JFS Newsletter no. 63, November 2007. Accessed January 2, 2019. www.japanfs.org/en/news/archives/news_id027839.html 48 Kim, Yeon Mee, Hyun Soo Kim, Soo Young Moon, and So-Yeon Bae. “Ubiquitous eco-city planning in Korea: A project for the realization of ecological city planning and ubiquitous network society.” In REAL CORP 2009: Cities 3.0—Smart, Sustainable, Integrative, 2009. Accessed January 2, 2019. http://geomultimedia.org/archive/CORP2009_174.pdf 49 Lützkendorf, Thomas, Greg Foliente, Maria Balouktsi, and Aoife Houlihan Wiberg. “Net-zero buildings: Incorporating embodied impacts.” Building Research & Information 43, no. 1 (2015): 62–81. 50 Weckend, Stephanie, Andreas Wade, and Garvin Heath. “End-of-life management: Solar photovoltaic panels.” International Renewable Energy Agency, June 2016. Accessed January 2, 2019. www.irena.org/publications/2016/ Jun/End-of-life-management-Solar-Photovoltaic-Panels

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Chapter 5

Future drivers and economics

Net zero building drivers can generally be grouped into five main categories: environmental drivers, regulatory drivers, human health drivers, technology drivers, and economic drivers (see Figure 5.1).

Figure 5.1 Drivers for net zero practice (by Emma Weber and author)

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Future drivers and economics

Environmental drivers Many studies indicate that sustainable and energy-efficient buildings are important factors in meeting the goal of a carbon emissions reduction of 80% by 2050. As outlined by the UN Environment Programme, this path toward a temperature increase of less than 2 °C requires reducing global energy and process-based carbon emissions by 60% by 2050, compared to a 2012 baseline.1 Overall, the building and construction industry is responsible for about 30% of global greenhouse gas emissions, 32% of global energy expenditures, and 40% of global waste.2 With energy consumption of buildings expected to increase and the projection of large construction activities within the next decade, emissions from the building sector could double by 2050 if no action is taken. Furthermore, energy demand is expected to rise by 50% by 2050.3 In COP21, the building sector was identified as the key sector, based on its mitigation potential. As the president of COP21, the French government organized and devoted one day as “Buildings Day” and has supported the development of the Global Alliance of Buildings and Construction, composed of 20 countries. Inefficient buildings have a profound impact on natural resource consumption, public health impact, and productivity improvement. To unlock the massive energy and CO2 emissions reduction potential, an additional $220 billion investment in the building industry is required to improve technology and retrofit inefficient existing buildings globally.3 Most countries have realized the important role of the building industry and have instigated regulations and mandates accordingly to help realize the large environmental impact reduction contributed by energy-efficient buildings.

Regulatory drivers: mandates, regulations, and incentives Closely related to environmental drivers, building regulations and energy policies have been the primary drivers for net zero buildings globally, and this trend will continue in the next decades. This section describes the major mandates, regulations, and incentives worldwide that promote the adoption of the net zero energy building design. Building codes and standards have been used as tools to enable new or existing buildings to address design and construction concerns, such as safety, comfort, occupants’ health, and energy efficiency. One of the oldest building codes to incorporate energy efficiency was established in 1961 in Denmark, later evolving into the Building Regulation. In most building regulations, there are maximum limits on energy demand or minimal energy efficiency requirements for buildings. Compliance with a building code will influence a building’s energy performance, and the decisions made during the design and construction phases will influence decades of building use. Building energy codes and regulations serve as a baseline to ensure that design teams and building owners take advantage of all opportunities to conserve energy, thus reducing the overall energy cost in the long run. The energy efficiency of a building is not a matter of choice by an individual designer or group of people; rather, it is a collective issue that influences the entire society and future generations.4

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The European Union The energy efficiency of buildings in EU member countries is based on directives, with the most influential directive for energy-efficient building design being the Energy Performance in Building Directive (EPBD). The first version was inspired by the Kyoto Protocol and approved in December 2002. This version required member states to comply within three years of the inception date, by January 2006. The legal binding and enforcement played an important role in pushing all member states to strengthen their building regulations and introduce energy performance certification of buildings.5 The second version, Directive 2010, focused on the Nearly-Zero Energy Building goal and clearly stated that “all new buildings shall be nearly zero energy buildings by 31 December 2020. . . . The same applies to all new public buildings after 31 December 2018.”5 The second version also requested that each member state set a minimum energy performance requirement and create a plan to meet the 2020 target. Each member state can decide its level of energy efficiency requirements, but these levels must be revised every five years and updated based on technological developments.4 The third version was published in October 2012, with several revisions based on the second version, and the fourth version was proposed in November 2016 to promote the use of smart technology in buildings. In addition to the new smart technology component, the 2016 version also outlined a goal of integrating long-term building renovation strategies in all building planning.6 Table 5.1 lists examples of countries’ requirements and targets.

The United States and Canada Although the United States and Canada are geographically close and have similar economic and political frameworks, there are substantial differences between the two countries’ energy system infrastructures and building energy performance regulations. The United States continues to heavily rely on fossil fuels; according to the Energy Information Administration’s 2016 report, 81% of electricity is obtained from fossil fuels, followed by 9.6% from nuclear fuels.7, 8 In Canada, Table 5.1  Selected national standards for energy-efficient new buildings4 Country

Target

Denmark

Reduce energy consumption by 75% by 2020 compared to 2006 baseline. Become a CO2 emissions-free country by 2050

Finland

Comply with Passive House standards by 2015

France

Energy-positive by 2020

Germany

Operate buildings without fossil fuels by 2020

Hungary

Zero emissions by 2020

Netherlands

Energy-neutral by 2020

Norway

Achieve Passive House standards by 2017

Switzerland

New buildings to achieve nearly zero energy by 2020

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only 25.7% of electricity is produced from fossil fuels, most being generated by hydroelectric plants. The two different energy infrastructures determine the baseline of source energy performance, as well as carbon emission differences, between the two countries. As for building energy codes, the United States did not employ a national building code until 1994. Currently, the country is generally reliant on two model codes that were developed by private organizations in collaboration with the US Department of Energy: the International Energy Conservation Code (IECC) by the International Code Council (ICC), and ASHRAE 90.1 Standard the American Society of Heating, Refrigerating and Air-Conditioning Engineers ASHRAE 90.1 Standard.9 Both standards were built on prescriptive efficiency requirements that are adopted by and adjusted to local conditions. Most states use the IECC for low-rise residential and simple buildings, whereas ASHRAE 90.1 is used for large and complex buildings or for trade and service buildings,9 addressing residential buildings with four floors or more above ground. Most recently, the International Green Construction Code (IGCC) was developed by the ICC in conjunction with other professional organizations. The IGCC is intended to serve as a baseline to facilitate the adoption of green building code requirements, and does not replace the IECC. While the IECC focuses on energy efficiency aimed at reducing total energy usage and the cost for building occupants, with provisions for both residential and commercial buildings,10 the IGCC was the first model code to include sustainability measurements from design to post-occupancy; however, the implications and effectiveness of the IGCC remain to be tested. Canada has one model code: the National Energy Code of Canada for Buildings (NECB). The NECB sets out technical requirements for the energyefficient design and construction of new buildings.11 It is as comprehensive as ASHRAE 90.1, including energy efficiency requirements for HVAC, building envelopes, lighting, service water heating, and other building systems. The NECB was created by a consortium of industry stakeholders, federal agencies, and research communities in 1997. In NECB 2015, several new prescriptive requirements were based on the forthcoming ASHRAE 90.1-2016 at that time. In the United States and Canada, there are no current building code requirements related to a net zero goal. However, in Canada, there is a national policy regarding the net zero goal. Federal government buildings need to meet both a 40% GHG reduction goal by 2030 and 100% renewable electricity by 2025.11 In both countries, certain local jurisdictions have their own targets. For instance, California Title 24 of the Energy Efficiency Standards for Residential and Nonresidential Buildings set the following net zero energy building goals: all new residential construction will be zero net energy by 2020, all new commercial construction will be zero net energy by 2030, 50% of commercial buildings will be retrofitted to zero net energy by 2030, and 50% of new major renovations of state buildings will be zero net energy by 2025.12

Japan and South Korea Japan has three building energy efficiency standards: Criteria for Clients on the Rationalization of Energy Use for Buildings (CCREUB), Design and Construction 78

Future drivers and economics

Guidelines on the Rationalization of Energy Use for Houses (DCGREUH) and Criteria for Clients on the Rationalization of Energy Use for Houses (CCREUH).13 All standards are part of the National Energy Conservation Law that was adopted in 1979. CCREUB is a mixture of performance and prescriptive energy codes for commercial buildings, while DCGREUH and CCREUB are energy codes for residential buildings.14 The first mandatory building standard on thermal insulation thickness was issued in 1977. However, from the mid-1980s to mid-1990s, the focus was on improving energy efficiency in the industrial sector, stalling energy efficiency efforts in the building industry until the late 1990s, when the central government shifted gear to promote energy efficiency in the building and transportation sectors.15 In 2014, after the Fukushima nuclear disaster,i the Japanese central cabinet passed an energy policy to promote a zero energy goal for all new public buildings by 2020 and all new residential buildings by 2030.16 Net zero building was recognized as the key energy- and electricity-saving concept in the government’s national strategic documents. The 2016 fiscal year budget of METI’s Agency of Natural Resources of Energy dedicated a large portion to promotional projects for energy efficiency technology that could be used for houses and buildings.16 Examples of net zero energy houses in Japan include the Sekisui House Head Office (Umeda Sky Building, see Figure 5.2), Sakai City, the first net zero city, and the MUJI Wood House. In South Korea, the Building Design Criteria for Energy Saving (BDCES) covers most aspects related to building energy efficiency. First published in 2001, the BDCES was a product of intensive revision of existing standards and a review of building energy codes of several countries.17 Like other codes, the BDCES is a prescriptive standard covering four main sections: construction design, machinery design, electric facility design, and renewable energy facility design. Regarding a net zero or zero carbon development goal, South Korea

Figure 5.2 Sekisui House Head Office in Osaka

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Future drivers and economics

published the Fundamental Law on Low Carbon Green Growth in 2010, which relates to green building expansion, rating systems, and emissions reductions. South Korea has set a goal for all houses to meet the zero energy goal by 2020, and other buildings from 2025 onward.

China Since 1986, China has established and issued a series of building energy codes for new construction, including the Design Standard for Energy Efficiency of Residential Buildings in Severe Cold and Cold Zones (1986 DSEETB), the Design Standard for Energy Efficiency of Public Buildings (2005), and the Code for Acceptance of Energy Efficient Building Construction (2007). The acceptance code has had the most impact. It enforces compliance with building efficiency requirements mandatory for the final acceptance of a construction project, lifting energy efficiency standards and codes of equal importance such as safety-related building codes.18 From 1986 to 2015, approximately 44 new and revised building energy efficiency-related standards were issued by the Ministry of Housing and Urban-Rural Development (MOHURD) and Ministry of Finance and State Council. Recently, MOHURD developed a long-term energy efficiency improvement plan, and net (or near) zero energy increase has become a critical component. Its goal is to achieve an overall energy efficiency level of 82% in residential buildings and 79% in commercial buildings by 2030, compared to a 1980 baseline performance.19 Similar to Australia and New Zealand, net zero building efforts in China are currently individual- and volunteer-based; there are no policies or building codes with requirements related to net zero energy or net zero emissions.

Australia In 2000, the Australian central government initiated an effort to reduce green­ house gas emissions from building sectors. This initiative adopted a two-pronged approach: a mandatory minimum energy performance requirement and voluntary compliance with an energy efficiency performance goal. Both approaches were reflected in the Building Code of Australia (BCA).20, 21 The BCA is a national-level building regulation developed by the Australian Building Codes Board—a government agency responsible for the development and administration of Australian building codes—to aid the design, construction, and use of buildings throughout Australia. In the current version of the BCA, a successful five-star system is used to rate the energy efficiency of a building’s performance. Consequently, the BCA has facilitated the market transformation toward higher building energy efficiency. Currently, Australia does not have an explicit net zero building goal incorporated in policy or regulations, and most such development has been voluntary.

Comparing the building energy codes and consumption status Many countries have mandated energy-efficient building design and construction by creating national building energy codes, which are often implemented

80

Continent

Assessment Standard for Green Building

Energy Conservation Building Code

China

India

2002

Energy Conservation Law

2007

2006

2010

1980, 1992, 2008

Criteria for Clients on the Rationalization of Energy Use for Houses

Building Design Code for Energy Saving

1998, 1992, 1999, 2003, 2006, 2008

Design and Construction Guidelines on the Rationalization of Energy Use for Houses

South Korea

2009

Rational Use of Energy Within Buildings

Japan

Year

Code title

Country

New non-residential

All

Residential

New commercial

Residential

Residential

New residential

Building types

Table 5.2  Comparison of major building energy codes and regulations23

Asia Bureau of Energy Efficiency, Ministry of Power, Government of India with support from USAID ECO II Project

Ministry of Housing and Urban-Rural Development

Ministry of Land, Transport and Maritime Affairs (MLTM)

Ministry of International Trade and Industry and the Ministry of Construction

Ministry of Construction

Ministry of Land, Infrastructure and Transport

Institution

All

Hot summer/cold winter, Hot summer/ warm winter

Cold, temperate

Severe cold

All

All

Climate zones

(continued)

Mandatory

Mandatory

Mixed (mandatory for buildings of 300–500 m2)

Mandatory

Stringency

Continent

North America 2009, 2014 2015 2015

Energy Policy Act

Energy Independence and Security Act

ASHRAE Standards 90.1, 100, 105, 189.1

International Energy Conservation Code

Executive Order 13693 “Planning for Federal Sustainability in the Next Decade”

USA

National Energy Code of Canada

2007

H1 Energy Efficiency, 3rd Edition

New Zealand

Canada

1992 2005

OIB Directives 3 and 6

Australia

1997–2015

2011

2015

2012

Code for Environmental Sustainability of Buildings, 3rd Edition

Singapore

Year

Code title

Country

Table 5.2  (continued)

Oceania All

All

All

All

All

All

Residential

All

New nonresidential and residential

Building types

National Research Council Canada

Executive Order of Federal Government

International Code Council

American National Standards Institute

Act of Congress

Congressional Act

Ministry of Business, Innovation and Employment

Australian Institute of Construction Technology

—

Institution

All

All

All

All

All

All

All (Climate 1–3)

All

Climate zones

Mixed

Mixed

Mandatory

Mixed

Mixed

Mandatory

Mandatory

Mandatory

Stringency

Europe 2011 2015

Thermal Regulation

National Building Energy Code

Decree for Energy Efficiency Requirements in Buildings

France

Italy

2005, 2012

2010

Building Regulations

Denmark

2007, 2009, 2013, 2014

Energy Saving Ordinance

Germany

Existing nonresidential, existing residential, new non-residential, new residential

Residential

Non-residential

All

All

Ministry of Economic Development

Ministry of Economic Development

Centre Scientifique des Techniques du Bâtiment, on behalf of the Ministry of Sustainable Development and Energy

Ministry of Business and Growth/Danish Business Authority

Federal Ministry of Transport, Building and Urban Development, Federal Ministry of Economics and Technology

All

All

All

All

All

(continued)

Mandatory

Mandatory

Mandatory

Mandatory

Mandatory

Continent

Thermal Performance of Buildings

Residential Building Code Article 4.1.10

Russia

Chile

2014

2003

2010

2010

Building Regulations (Northern Ireland)

Building Regulations

2004, 2011

Technical Residential Handbook for Building Regulations 2004 (Scotland 2011)

Sweden

2010

Building Regulations (England and Wales)

UK

Year

Code title

Country

Table 5.2  (continued)

SA

New residential

New residential

New non-residential

New residential

New residential and non-residential

New residential

Building types

Ministry of Housing and Urban Development

Ministry of Regional Development

Swedish Board of Housing, Building and Planning

Department of Finance and Personnel

Scottish Government: Building Standards Division

Department for Communities and Local Government

Institution

All

All

All

All

All

All

Climate zones

Mandatory

Mandatory

Mandatory

Mandatory

Mandatory

Mandatory

Stringency

Future drivers and economics

at regional levels. These building codes vary worldwide in levels of coverage and stringency. Table 5.2 lists building codes and energy mandates from highly influential countries. The United States and European Union member states have higher building energy efficiency requirements than some developing countries, such as China and India. If those countries built according to US or EU standards, presumably the overall energy consumption from the buildings would decrease. However, high energy efficiency building requirements do not directly translate to lower energy consumption or energy usage intensity. As of 2012, China, India, and Mexico had the lowest energy intensities (per capita use) for both residential and commercial buildings due to low energy demands. Italy and South Korea had the highest energy intensities in the commercial building sector, while Russia has the highest in the residential building sector, followed by South Korea.22 These energy usage intensities are not necessarily due to less stringent building energy codes and standards; in fact, quite the opposite could apply. Based on the author’s research and studies, the conclusion could be formed that lower energy demand and usage intensities in developing countries are connected to energyconscious and conservative behaviors that are reflected in a building’s operational schedule. These countries typically shut down their operational systems during non-office hours and at weekends—unlike some developed countries such as the United States, where buildings are operated on a 24/7 schedule and the building systems are never completely turned off. Further research and analysis are needed to fully understand this phenomenon.

Human health drivers Consideration of the impact of buildings on human health and well-being is not a new research interest; it can be traced back to the 1970s, when outbreaks of sick building syndrome (SBS) first gained public attention. Unlike traditional buildings that relied on passive design strategies, most modern buildings utilize mechanical systems to create a controlled indoor environment. This new type of design required mechanical ventilation systems to circulate fresh air and control the temperature, humidity, and other environmental factors.24 Before the first energy and oil crisis of the 1970s, the standard building ventilation rate was around 15 ft3 per minute (cfm) (0.42 m3 per minute), or 25 m3 per hour (cmh), for each building occupant, and the ventilation moved fresh air from outside into buildings, diluting and removing body odors. To conserve energy following the 1973 oil embargo, the Energy Conservation Act called for a reduction in the ventilation rate, to 5 cfm (0.14 m3 per minute).ii Insufficient ventilation was a major cause that contributed to SBS. Based on the definition by the Environmental Protection Agency (EPA), SBS “is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified.”25 The term “building-related illness” is used to describe an illness that could be “attributed directly to airborne building contaminants.”26 In a document produced by the World Health Organization, the committee suggested that many newly constructed and renovated buildings could be subject to excessive complaints related to SBS, where

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Future drivers and economics

the causes of SBS and poor indoor air quality could be directly related to inappropriate designing and planning and occupant behaviors. Since then, the movement of designing healthy buildings in response to SBS has largely focused on prevention and defense mechanisms to protect building occupants by “designing out” potential health hazards, thus reducing illnesses and injuries due to a dangerous built environment. With increased hazards to human health due to large quantities of unsustainable construction activities, this issue has reemerged recently as a priority not only in the building industry but also in the public health sector. Chapter 3 covered the proven correlation between human health and indoor environmental quality. With the increasing number of new and advanced building materials and systems entering the market, concerns about long-term health impacts have become apparent. From the perspective of an architectural designer, buildings must be designed to protect the health, safety, and welfare of occupants.27 Whether these new materials with energy-saving benefits could have a negative impact on human health is largely unknown. To pave the way for further investigation, we need to first categorize different health issues. In this book, building-related health issues can be categorized into two sources: indoor air quality and building materials.

Indoor air quality Historically, poor indoor air quality (IAQ) has been directly associated with health problems. Inadequate ventilation combined with historical wood-burning heating systems produced large amounts of soot that caused many respiratory problems. In modern building systems, ventilation was mechanically controlled, which proved to be quite efficient. Later, a new trend emerged where highly insulated buildings were designed and built to reduce the heat transfer, thus reducing energy consumption. In this type of highly controlled environment, small occupant behavior changes could have a larger impact since the use of space is unpredictable and indoor air quality could be compromised. From 1990 to 2000, many studies on IAQ and human health were carried out, with the results suggesting that when designing tightly and mechanically controlled spaces, users’ behavior needed to be taken into consideration.

Advanced building materials and construction A building’s design, materials, and method of construction, as well as the construction process, may affect the health of the occupants, operatives, and general population over its entire life cycle.26 Research indicates that energy-efficient buildings have a better chance of mitigating heat stress.28 It has also been shown that several diseases, deteriorating human health, and even death are associated with certain indoor environment characteristics. Respiratory diseases are related to the indoor concentration of toxins, volatile organic compounds, particular pollutants, and carbon dioxide concentration. These pollutants usually originate in the building materials,29 and their impact is exacerbated by inadequate airflow within the space through airtight building enclosures. Certain green building design guidelines

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Future drivers and economics

or rating systems follow a holistic approach to integrate requirements of using “healthy” building materials, suggesting that these materials produce less or none of the byproducts that could endanger human health. For instance, the only organization managing the net zero building label, the Living Future Institute, has specified a large number of building materials in its red list that are prohibited in sustainable buildings. For example, asbestos, known for its strength and heatresisting capabilities, is often found in building insulation materials. However, it is a known human carcinogen that increases the risks of lung cancer, mesothelioma, and asbestosis. Having more streamlined and stringent sustainable building requirements will help to control and reduce the use of harmful materials while achieving the energy conservation goal.

Future needs beyond survival: well-being In the past, the focus was on basic “survival needs”; however, it has shifted to “well-being needs.”30 These two concepts were originally introduced by human ecologist Stephen Boyden in 1971. Survival needs deal with aspects of the environment that directly affect human health, such as clean air and water, proper temperature and humidity, and opportunities for rest and sleep.30 Well-being needs deal with more indirect needs, such as fulfillment, attachment, psychosocial needs, and quality of life. While most understand the connection between the built environment and human health, we are less familiar with the relation between building energy efficiency and health. Since the invention of the first large-scale electrical air conditioning unit in Buffalo, New York in 1902, many technological advances have produced substantial improvements in energy efficiency whereby energy can be exploited to service human needs.31 This continuing trend has been accompanied by an equally notable increase in global energy consumption, which correlates with socioeconomic development in the last century. Consequently, the feasible gains from energy-efficient technology in cities, buildings, and homes could contribute to future mitigation of carbon emissions. More importantly, the connection between health and buildings will become the major research and practice focus for the next generation. In the next decade, the definition of net zero will be expanded, and the focus will center on human health.

Technology drivers: smart building Growth in green buildings and smart cities has sparked an interest in smart buildings. The market of smart building technologies is expected to grow exponentially over the next five to ten years. A report projected that in the United States alone, the smart building market will grow from $5.71 billion in 2016 to $31.74 billion by 2022, with a compound annual growth rate of 34%.32 Major reasons for smart building growth include the benefits of energy-efficient buildings and a carbon emissions reduction. Key technologies that will enable this growth include four indicators: predictive maintenance, convergent networks and wireless access, biometric integration, and self-awareness.33 The majority of those technologies are currently available, but have not been fully integrated into building designs

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Future drivers and economics

and construction. Applying these smart technologies to buildings would provide a healthy built environment where empowered occupants control their local spaces. Predictive maintenance could be realized through the Internet of Things (IoT). This phrase has become a buzzword to describe all things capable of sharing their data, not only with each other, but also with other information technology systems, enabling far deeper insights into how to operate buildings in the most efficient and effective way. Integrating a variety of building systems and equipment has always been challenging to design and facility management teams, but IoT could help green buildings connect devices and equipment and share data. This would create a shift from prevention and repair to issue-based maintenance in real time by using the historical performance data of equipment that may potentially malfunction.34 Currently, maintenance and repairs are passive and problem-based. When equipment encounters problems, technicians are sent to fix it. However, with real-time feedback and historical data, predicted interventions can be scheduled beforehand, moving the focus to issue-based tasks. For instance, a US company called Aucuryiii uses vibration and ultrasonic sensors to monitor and predict equipment maintenance. It has its own mobile and Web apps to connect all sensors, machines, and diagnostic tools so that clients receive results instantaneously. Wireless access is key to creating convergent networks. A convergent network with wireless access empowers end-users with an understanding of and control over their environment, with that control being based on personal preference. A top green and smart development is Edge, an office building in Amsterdam fitted with 28,000 sensors that track the building’s energy consumption, water usage, lighting level, temperature, humidity, and space usage (see Figure 5.3). Workers there utilize a cutting-edge system: a smartphone app that connects them to the building through wireless connection. The wireless connection and network allow employees to locate working stations, parking spaces, and their teammates with this easy-to-use mobile app.

Figure 5.3 Edge exterior32

88

Figure 5.4  Central dashboards track building performance in Edge35

Future drivers and economics

Two upcoming technological developments for smart and green building are biometric integration and self-awareness systems. By using sensors to track demand and changes and proactively control space settings, research has shown a positive correlation between occupancy satisfaction and a building’s intelligence. As the accuracy of sensors improves and control systems become more sophisticated, parameters embedded within individual occupancies can be integrated into the system. For instance, when an employee enters a space, sensors and face recognition technology will recognize and register the occupancy’s preferred lighting level and room temperature, proactively adjusting the space settings to best fit that individual’s needs. This is the system implemented in Edge (see Figure 5.4). Edge currently produces more electricity than it consumes—besides being a net zero energy building, it is also a net positive energy building. Historically, the adoption of sustainable design principles and smart technology in green buildings has progressed simultaneously, yet somewhat separately. Sustainable building principles, especially net zero building, have focused more on the building design and materials used, whereas building automation and system intelligence have evolved to optimize building operations. As these advanced technologies mature, a large overlapping and merging of the energy-efficient building movement and smart building initiatives will occur. Furthermore, one fundamental difference between the future net zero building movement and the conventional green building movement is that the former focuses on long-term building operation and considers all things related to efficiency from a life cycle perspective. Currently, we have already seen net zero or nearly zero energy building reach their goals through the integration of smart technologies, such as sensors and auto-controls of smart buildings (see Figure 5.5). Chapter 6 will focus on the development and potential of smart materials and systems in net zero building. Figure 5.5 Intersection between smart building and green building (by author and Emma Weber)

90

Future drivers and economics

Economic drivers: the cost debate There is a longstanding perception that sustainable building is expensive because of the integration of advanced green technologies. This has been identified as one of the major obstacles in promoting net zero energy buildings. Table 5.3 shows a number of studies the author has collected that relate to the cost of green buildings. To date, the majority of empirical studies on green building premium costs have been conducted by professional agencies instead of academic researchers. This certainly has its advantages, such as having firsthand data from real projects. However, since most trade publications are not transparent about their research methodology and data sources, it is difficult to understand the wide range of cost differences, and there is no clear trend to indicate whether costs are increasing or decreasing. More than 90% of the results in the investigated empirical studies categorize the extra cost of green building within the range of -0.4% to 46%, which is considerably wide.36 The premium cost of green building has been speculated as due to the incorporation of alternative power sources and energy-efficient appliances and equipment. Moreover, the increase in the base building cost is insignificant. As shown in Table 5.3, six out of 32 studies revealed the green building premium cost as being 10% and above. In contrast, 26 out of the 32 studies indicated that green buildings can be achieved at a very low cost premium. In an ideal case, there is no significant cost difference between sustainable and conventional building. One influential study was commissioned by the Sustainable Building Task Force in California and conducted by a group of experts from a federal agency and national laboratory as well as consultants. They analyzed 33 LEED buildings with the aim to define, document, and analyze the costs and financial benefits of green buildings. The financial benefits estimated in this study are a measure of financial benefits to the State of California as a whole. The data indicates that the average construction cost premium for green buildings is almost 2%, or about $4/ft2 ($44.40/m2), which is substantially less than what is generally perceived.37 They also concluded that green buildings cost less to operate, save energy by an average of 30%, and possess additional financial benefits, such as

Table 5.3  Green cost premium higher than conventional building36 No. of studies < 0%

2

0%

8

0–5%

10

6–10%

6

11–20%

5

21–30%

0

31–40%

0

> 40%

1

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Future drivers and economics

less waste, lower water costs, lower environmental and emissions costs, lower maintenance costs, and improved productivity and health.37 Another important study that has been cited widely was conducted by a professional cost consulting company, Davis Langdon. In its 2004 study, Costing Green: A Comprehensive Cost Database and Budgeting Methodology, the research team focused only on the construction cost, since construction cost implications largely impact an owner’s decision-making. They compiled a database of information from nearly 600 distinct projects in 19 different states, with project types including academic buildings, laboratories, offices, hospitals, and museums, among others. The team concluded that many projects achieve a sustainable design within their initial budget or with very small supplemental funding.38 In 2007, Davis Langdon published another study to verify the results from the 2004 study. It found that the main obstacle to promoting sustainable building was not the cost, but the idea that green is an added feature.39 Despite the widespread perception of green building being expensive, there are not adequate empirical studies and evidence to support this claim, and the issue of a high green cost premium is still debatable.

Conclusion The drivers identified in this chapter will motivate designers, clients, and government officials to build green and ultimately promote net zero building. Recognizing these drivers can provide a salient way to steer communities toward more socially and economically sustainable development. Countries like the United States, EU member states, Singapore, China, and South Korea are taking the lead in utilizing these drivers to speed up the adoption of net zero practices. The economic driver may play a particularly detrimental role since current green building development is often discouraged by the perceived higher initial cost. Particularly in developing countries, where the typical building’s life span is shorter than its counterparts in developed countries, it is more critical to produce a reliable and precise estimate of the green building premium cost. The second most important, yet underutilized, driver is the health driver, which could accelerate in the near future due to the global recognition of health impacts from the built environment. Finally, compared to the other commonly recognized and understood drivers—regulatory and environmental drivers—the potential influence of the technological driver is not fully understood yet. Chapter 6 will dive deep into one of the indicators of the technological driver: advanced building materials and systems.

Notes i The Fukushima Daiichi nuclear disaster was initiated primarily by the tsunami following the Tohoky earthquake on March 11, 2011. ii In the 1980s, after a huge outbreak of health issues related to buildings, as well as the fading of the energy crisis, the American Society of Heating Refrigerating and Air-Conditioning Engineers revised the ventilation standard to 17 cfm (0.48 m3 per minute, or 34 cmh) per occupant for regular office spaces, and the same value was being used in 2017. iii See www.augury.com/solution/platform-overview (accessed January 2, 2019).

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Future drivers and economics

References 1 Otto, Martina. “What the Paris Climate Agreement means for the building sector.” UN Environment Programme. Accessed January 2, 2019. www. swisscontact.org/fileadmin/user_upload/COUNTRIES/Peru/Documents/ Content/Building_Sector_Paris_Agreement_-_IGBC.pdf 2 Nejat, P., F. Jomehzadeh, M. M. Taheri, M. Gohari, and Muhd Zaimi Abd Majid. “A global review of energy consumption, CO2 emissions and policy in the residential sector (with an overview of the top ten CO2 emitting countries).” Renewable and Sustainable Energy Reviews 43 (2015): 843–862. 3 Transition to Sustainable Buildings: Strategies and Opportunities to 2050. International Energy Agency, 2013. Accessed January 2, 2019. www.iea. org/Textbase/npsum/building2013SUM.pdf 4 Janssen, Rod. “Nearly zero energy buildings: Achieving the EU 2020 target.” Sustainable Energy Week (2011): 1–16. 5 “Directive 2002/91/EC of the European Parliament and of the Council.” Official Journal of the European Communities. Accessed January 2, 2019. https://eur-lex.europa.eu/eli/dir/2002/91/oj 6 “Commission welcomes agreement on energy performance of buildings.” European Commission, December 19, 2017. Accessed January 2, 2019. http://europa.eu/rapid/press-release_IP-17-5129_en.htm 7 “Maps: Overview & general.” US Energy Information Administration. Accessed January 2, 2019. www.eia.gov/maps/ 8 “The World Factbook.” Central Intelligence Agency. Accessed January 2, 2019. www.cia.gov/library/publications/resources/the-world-factbook/index.html 9 Laustsen, Jens. “Energy Efficiency Requirements in Building Codes, Energy Efficiency Policies for New Buildings. International Energy Agency Information Paper, 2008, 477–488. 10 “Energy efficient building codes: PA and NJ,” Consortium for Building Energy Innovation. Accessed January 2, 2019. http://cbei.psu.edu/energyefficient-building-codes-pa-and-nj/ 11 “National Energy Code of Canada for Buildings 2015.” National Research Council Canada. Accessed January 2, 2019. www.nrc-cnrc.gc.ca/eng/ publications/codes_centre/2015_national_energy_code_buildings.html 12 “Zero net energy,” California Public Utilities Commission. Accessed January 2, 2019. www.cpuc.ca.gov/ZNE/ 13 Asia Business Council. Energy Efficiency Building Standards in Japan. Asia Business Council. Accessed January 2, 2019. www.asiabusinesscouncil. org/docs/BEE/papers/BEE_Policy_Japan.pdf 14 Evans, Meredydd, Bin Shui, and T. Takagi. Country Report on Building Energy Codes in Japan (PNNL-17849). Pacific Northwest National Laboratory, 2009. 15 Asia Business Council. Building Energy Efficiency: Why Green Buildings Are Key to Asia’s future. Asia Business Council, October 2008. Accessed January 2, 2019. www.asiabusinesscouncil.org/docs/BEE/BEE2008Overview.pdf 16 “Promotion of Zero Energy Building and Zero Energy Houses,” IEA—Japan. Accessed January 2, 2019. www.iea.org/policiesandmeasures/pams/japan/

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17 Evans, M., B. Shui, and A. Delgado. Shaping the Energy Efficiency in New Buildings (PNNL-122267). Pacific Northwest National Laboratory, September 2009. Accessed January 2, 2019. www.energycodes.gov/sites/default/files/ documents/CountryReport_APP_Building_Code_Comparison.pdf 18 Lo, Kevin. “A critical review of China’s rapidly developing renewable energy and energy efficiency policies.” Renewable and Sustainable Energy Reviews 29 (2014): 508–516. 19 Li, Danny HW, Liu Yang, and Joseph C. Lam. “Zero energy buildings and sustainable development implications—a review.” Energy 54 (2013): 1–10. 20 Shui, B., M. Evans, and S. Somasundaram. Country Report on Building Energy Codes in Australia.” Pacific Northwest National Laboratory, April 2009. Accessed January 2, 2019. www.energycodes.gov/sites/default/files/ documents/CountryReport_Australia.pdf 21 “Building Code Implementation—Country Summary.” International Partnership for Energy Efficiency Cooperation. Accessed January 2, 2019. www.gbpn.org/ sites/default/files/Australia_Country%20Summary%20_0.pdf 22 Young, Rachel. “Global approaches: A comparison of building energy codes in 15 countries.” American Council for an Energy-Efficient Economy Summer Study on Energy Efficiency in Buildings 3 (2014): 351–366. 23 “Databases & Tools.” Global Buildings Performance Network. Accessed January 2, 2019. www.gbpn.org/databases-tools 24 Stolwijk, J. A. “Sick-building syndrome.” Environmental Health Perspectives 95 (1991): 99. 25 Samet, Jonathan M., and John D. Spengler. Indoor Air Pollution: A Health Perspective. Johns Hopkins University Press, 1991. 26 Ajayi, Saheed O., Lukumon O. Oyedele, Babatunde Jaiyeoba, Kabir Kadiri, and Sunday Aderemi David. “Are sustainable buildings healthy? An investigation of lifecycle relationship between building sustainability and its environmental health impacts.” World Journal of Science, Technology and Sustainable Development 13, no. 3 (2016): 190–204. 27 Bayer, Charlene W., Judith Heerwagen, and Whitney A. Gray. “Health centered buildings: A paradigm shift in buildings design and operation.” In Proceedings of the 10th International Healthy Buildings Conference, 2012, 8–12. 28 Ren, Z., X. Wang, and Z. Chen. “Energy efficient houses for heat stress mitigation: 2009 Melbourne heatwave scenarios.” Presentation at the 10th International Healthy Building Conference, July 8–12, 2012. 29 Berge, Bjorn. The Ecology of Building Materials. Routledge, 2009. 30 Heerwagen, Judith H. “Design, productivity and well being: What are the links?” Presentation at the AIA Conference on Highly Effective Facilities, Cincinnati, OH, 1998. 31 Wilkinson, Paul, Kirk R. Smith, Sean Beevers, Cathryn Tonne, and Tadj Oreszczyn. “Energy, energy efficiency, and the built environment.” The Lancet 370, no. 9593 (2007): 1175–1187.

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32 “Connected lighting: From ethernet to li-fi internet,” Archdaily, December 21, 2015. Accessed January 2, 2019. www.archdaily.com/779169/connectedlighting-from-ethernet-to-li-fi-internet 33 “5 technologies that are making smart buildings.” Construction Dive, November 2, 2016. Accessed January 2, 2019. www.constructiondive.com/ news/5-technologies-that-are-making-smart-buildings-smarter/429582/ 34 “The smartest building in the world.” Bloomberg, September 23, 2015. Accessed January 2, 2019. www.bloomberg.com/features/2015-the-edgethe-worlds-greenest-building/ 35 “The smartest building in the world.” Bloomberg, September 23, 2015. Accessed January 2, 2019. www.bloomberg.com/features/2015-the-edgethe-worlds-greenest-building/ 36 Dwaikat, Luay N., and Kherun N. Ali. “Green buildings cost premium: A review of empirical evidence.” Energy and Buildings 110 (2016): 396–403. 37 Kats, Greg, Leon Alevantis, Adam Berman, Evan Mills, and Jeff Perlman. The Costs and Financial Benefits of Green Buildings: A Report to California’s Sustainable Building Task Force, October 2003. 38 Matthiessen, Lisa Fay, and Peter Morris. Costing Green: A Comprehensive Cost Database and Budgeting Methodology. Davis Langdon, July 2004. Accessed January 2, 2019. https://legacy.azdeq.gov/ceh/download/greencost.pdf 39 Matthiessen, Lisa Fay, and Peter Morris. Cost of Green Revisited: Reexamining the Feasibility and Cost Impact of Sustainable Design in the Light of Increased Market Adoption. Davis Langdon, July 2007. Accessed January 2, 2019. http://global.ctbuh.org/resources/papers/download/1242cost-of-green-revisited-reexamining-the-feasability-and-cost-impact-ofsustainable-design-in-the-light-of-increased-market-adoption.pdf

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Chapter 6

Advanced building materials and systems Smart green building

Our lifestyles and buildings have progressed over the past decades through the innovation and advancement of materials, construction technologies, and products. Apart from a few exceptions, it is not spectacular buildings and housing types that define the present—but instead the changes in building technology and automation.1 In the early 2000s, we have experienced how smart technologies, such as the iPhone, have changed many people’s daily routines, communication, and work environments. In the next decade, we will experience a major evolution in the building industry: buildings with various degrees of high intelligence that can respond to external changes in organic and ecological methods, through the utilization of adaptive, smart, and highly efficient materials and products. Depending on the acceptance and understanding of those materials and systems and their effects on buildings, our future building stock could change from a high-energy consuming system to a decentralized, efficient, and smart system. These projected changes are positive and challenging at the same time.

Nanotechnology The definition of nanotechnology is both controversial and consequential. It is controversial because how the term is defined has important implications for how it is managed and marketed. Several international organizations that handle standards are working to improve existing nano definitions, and their work may result in greater agreement. Currently, all nano definitions are based on the physics and chemistry of technology and relate to size. Nanotechnology refers to the technology of the very small—the manipulation of objects at the level of individual atoms and molecules. The US National Nanotechnology Initiative (NNI), the interagency effort to coordinate federal funding for nano research and development, defines nanotechnology as “The understanding and control of matter at dimensions of roughly 1 to 100 nanometers.”2 A nanometer is a billionth of a meter. A human hair is 60,000–120,000 nanometers wide, and a red blood cell is 2000–5000 nanometers wide.2 Objects at the nanoscale can be seen only with techniques such as super-magnifying scanning tunnel microscopes, which were first used in the mid-1980s.

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The concept of nanotechnology was proposed by Nobel Prize-winning physicist Richard P. Feynman during a lecture at the California Institute of Technology titled “There’s plenty of room at the bottom.”3 This lecture has initiated innovations related to nanotechnology, prefiguring the possibilities associated with the transformation of matter at the molecular level. Studies conducted by Feynman and his institution have laid the basis for a radical transformation of the nanoscientific horizon, starting with the possibility of the miniaturization of computers, which essentially led to most of the technological innovations produced in the last 50 years.4, 5 Nanotechnology represents one of the fastest-growing industrial sectors worldwide in recent years, and its application spans many disciplines. The building industry, particularly energy-efficient building design, has shown interest in nanotech innovation and application, with aims to improve building performance and reduce energy consumption and carbon emissions. The 2018 US Federal Government budget provided $1.2 billion in nanotechnology development.6 China, Japan, South Korea, and several European nations are competing with the United States to lead in nanotechnology development, with Russia announcing a $3.3 billion investment in December 2007 to fund research and a development program for nanotechnology until 2015.7 Feynman was right in his prediction—the room-sized computers of the 1950s were replaced by their miniaturized successors: single, hand-held devices. But could he have had an inkling of the transformation that smart devices, from mobile phones to tablet computers, have brought to modern life? Ultimately, every industry that involves manufactured items will be impacted by nanotechnology.8 In the next decades, nanotechnology will play a very important role in designing and constructing net zero or high-performance buildings to meet ever-increasing needs. Nanomaterials are being used in regular building materials, sensors, solar cells, or other mechanical or electronic equipment which work toward achieving the net zero goal. We will examine two current nanotechnology uses in buildings.

Insulation The most common application of nanomaterials in buildings is insulation. Traditional insulation materials are made from fiberglass or polystyrene. A typical polystyrene extrusion will provide an insulation R-value of 5 per inch (25 mm); therefore, a 4 inch-thick (100 mm) rigid insulation board can provide an R-value of 20. Aerogel offers R-10 per inch, which is double the insulation value of a regular rigid insulation board. Aerogel was discovered in the 1930s,9, 10, 11 and since then, it has attracted much interest from various industries, including building, transportation, and electronics. The focus on aerogel as a superior insulation material is a relatively recent phenomenon of the past ten years. Currently, there are two different building application types that exist for aerogel insulation: (1) silica aerogels and (2) granular, aerogel-based translucent insulation materials, which are integrated into building products such as wall panels.12 The latter have been very popular among designers and building owners. One manufacturer, Kalwall, produces panels with numerous translucent insulation options, including Lumira aerogel with a thermal transmittance

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U-value up to 0.05 for translucent panels. The British School in Brussels and the Yale University Sculpture Building and Gallery used this product (see Figures 6.1 and 6.2). The Sculpture Building has a 4.2 m-high studio space with a fully glazed façade. To avoid compromising the building’s energy performance, the design team chose to use a triple-glazed curtain wall together with a Lumira aerogel translucent panel; the panel itself has an R-value of 20.

Structure Besides insulation, nanomaterials are also used in structural applications. They can be integrated into conventional structural materials—such as cement, concrete, steel, and wood—or used to make new structural materials. Nanotechnology Figure 6.1 Yale University Sculpture Building and Gallery13

Figure 6.2 Yale University Sculpture Building and Gallery13

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allows us to modify and control physical-chemical properties of traditional cement-based materials at the micro-scale. At the micro-scale, the properties can be precisely reset to “correct” and optimize the characteristics of a material to meet the final performance expectations, even without the addition of nanomaterials. For example, in high-performance concrete, modification of the mix design (depending on the type and size of the aggregates, type of additives, and water/cement ratio) can increase the mechanical strength and durability of concrete. Silica (SiO2) is present in conventional concrete as part of the normal mix; however, one of the advancements found in a study of concrete at the nanoscale is that particle packing in concrete can be improved by using nano-silica, which leads to a densifying of the micro nanostructure and the subsequent densification results contribute to improved mechanical properties. The nano-silica addition to cement-based materials can also control the degradation of concrete cause by the fundamental C-S-H (calcium-silicate-hydrate) reaction. A C-S-H reaction may lead to water penetration and calcium leaching in water, thus blocking such a reaction is a very important step towards improving concrete’s durability.14 Beyond concrete and other cement-based materials, nanotechnology can also be applied to steel and wood. Introducing nanoparticles to steel can produce stronger, more durable elements while possibly reducing the construction cost and time. The addition of nanoparticles—such as copper, carbon nanotubes, vanadium, molybdenum, magnesium, and calcium—can reduce the surface unevenness of steel, which then limits the number of stress risers and hence fatigue cracking.15, 16 This is important, as fatigue cracking could ultimately lead to structural failure. Furthermore, refinement of the cementite phase of steel at the nanoscale has produced high-strength steel cables, which have already been used in bridge construction and precast concrete. Nanowood is composed of nanotubes, or “nanofibrils”—lignocellulosic (woody tissue) elements that are twice as strong as steel.17 Nano sensors present another promising use of nanotechnology. In a report produced in 2006, European researchers predicted that harvesting the nanofibrils would: lead to a new paradigm in sustainable construction as both the production and use would be part of a renewable cycle. . . . These nonobtrusive active or passive nanoscale sensors would provide feedback on product performance and environmental conditions during service by monitoring structural loads, heat losses or gains, temperatures, moisture content, decay fungi, and loss of conditioned air.15

Phase-changing technologies Phase-change materials (PCMs) represent another type of new building material that could contribute greatly to energy-saving. A phase-change process involves transforming a material from one phase to another.18 The most commonly known phase-change material is water: melting ice can transform to liquid water and then to boiling water and water vapor, the transformation constituting a phase-change process. During the process, molecules rearrange themselves, causing an entropy

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change of the material system.19 Based on thermodynamic law, during the process, the material absorbs or releases thermal energy (heat) due to its change in entropy. The heat associated with the material mass is also defined as the latent heat of the material, and the capacity for storing latent heat of certain materials indicates the measurement of the total amount of thermal energy that can be stored within the material. During the melting of snow, the stored latent heat is absorbed. This is the reason why people feel colder during the snowmelt period compared to the snowfall period. The amount of latent heat is larger than sensible heat gain or loss at a magnitude of 10 K, and the latent heat of ice melting into water at 0 °C is about 330 kJ/kg. To change the same amount of water by 10 K requires only 42 kJ/kg of sensible heat.19 This means it takes almost ten times more energy to change ice into water than it does to increase the water temperature by 10 K. In a phase-change process, a significant amount of heat is transferred at a constant temperature, which is very useful for the heating and cooling supply in a building’s application. The types of materials that use their phase-changing ability for heating, cooling, or temperature stabilization purposes are called phase-change materials. Phase-change materials can regulate indoor temperature change as well as reduce heating and cooling demands. The typical method to decrease a building’s energy consumption is to reduce the heat flow through including additional insulation in a building’s enclosure system (roof and walls). This method does have its limitations, however: we cannot increase the thickness of the walls infinitely as the space is limited. Using thinner insulation materials, such as a thin nanoinsulator, could be one alternative. Another solution is to control the temperature difference within the layers of insulated assemblies of buildings to reduce the heat flow. Additionally, PCMs can help to maintain a constant temperature within the building envelope, since they can store and release heat to maintain temperatures despite a changing surrounding temperature. The energy absorption characteristic of PCMs can be used in different ways—either as a stabilizer to regulate the indoor temperature or as a thermal storage space to release/absorb heat in the environment depending on the direction of the phase change taking place.

Types of PCMs PCMs have been studied and tested for almost 40 years, with many studies concluding that PCMs can enhance building energy performance. One of those early studies was a research paper published by the US National Renewable Energy Lab in 1985, titled New Phase-change Thermal Energy Storage Materials for Buildings. Researchers examined PCM cool storage capabilities and concluded that three-quarters of the air conditioning energy cost could potentially be saved.20 There are three different types of PCMs: organic, inorganic, and eutectic materials. Organic PCMs are general chemically stable, do not suffer from supercooling, are noncorrosive and non-toxic, and have a high latent heat of fusion.19 The most common organic PCMs can be categorized into paraffinbased and non-paraffin-based. Non-paraffin-based PCMs are widely diverse, including alcohols and fatty acids. They have great freezing and melting properties; however, they are more expensive than paraffin-based PCMs.

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Inorganic PCMs have high thermal conductivity and heat of fusion, are nonflammable, and are relatively cheap. The most common inorganic PCMs are hydrated salts, which have a high heat storage capacity, at about 240 kJ/kg, and relatively high thermal conductivity, at approximately 0.5 W/mk.21 One of the early MIT solar house projects used hydrated salts as an insulation material for a solar hot water storage device (see Chapter 1). Compared to organic PCMs, inorganic PCMs are difficult to maintain during cycling, prone to supercooling, and can potentially develop phase segregation. Eutectici PCMs in general have low freezing points, and their volumetric storage density is slightly higher than that of organic compounds.22, 23 Figure 6.3 demonstrates the types of PCMs and their respective advantages and disadvantages.

Current PCM applications in buildings In the past 20 years, there has been a large interest in determining effective methods to integrate PCMs in building materials or assemblies. A variety of methods have been developed and different base materials tested, such as concrete, gypsum boards, and ceiling tiles.

Figure 6.3 Types of PCMS

TYPES

Advantages: Chemically stable No segregation Freeze without much supercooling High heat of fusion Recyclable

Advantages: High latent heat storage capacity High thermal conductivity Low-cost and readily available Non-flammable

Disadvantages: Low thermal conductivity Flammable Low latent heat storage capacity

Disadvantages: High change of volume Supercooling

Inorganic

Organic

Hydrated salts

Non-paraffin-based

Paraffin-based

Eutectics

Inorganic

Organic

Advantages: Higher latent heat storage capacity than organic PCMs Sharp melting point Disadvantages: Not widely available

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Passive approach: walls and floors Wallboard is one of the most common assemblies used in buildings; the large surface of wallboard makes it very suitable for the application of PCMs. A PCM wall is capable of capturing a large proportion of solar radiation on the walls or roof of a building.22 Wallboard provides a solar storage capability by absorbing excess solar heat and stabilizing the temperature within the wall, thus minimizing large temperature fluctuations within the building. These PCM walls enable passive solar design and shift the peak load to reduce energy consumption in a way that traditional frame constructions have been unable to do.20, 23 In order for a PCM wall to function properly, several factors need to be considered. The first factor is the melt temperature of the PCM integrated into the wallboard. Material types should be chosen that have phase transition temperatures similar to a human thermal comfort level, ranging from 20–28 °C, which is the normal indoor temperature range we base our designs upon. There are three primary methods to integrate PCMs into wallboard: direct impregnation, immersion, and encapsulation. Direct impregnation is the most-used method since it is simple, convenient, and economical and can potentially achieve a higher thermal storage capacity within the wallboard. In this method, a PCM can be directly mixed with concrete, gypsum, or other porous wall materials and easily tested in laboratory conditions.23, 24, 25, 26 This method was originally proposed by Feldman and his team,27 where a controlled heating bath was used for absorption of the PCM in aggregates. The PCM was then heated in a flask at a controlled temperature. Lastly, a certain quantity of regular building materials was inserted for PCM absorption under vacuum conditions. The mixed materials were left to dry for 48 hours before the excess PCM was filtered out.24 The immersion method has an advantage in its operation since its approach is easier: construction elements such as concrete or masonry blocks or wallboards are dipped into the liquid PCM; these materials absorb the PCM by capillary action. This method may cause a potential PCM leak if the wallboard is subjected to substantial outside temperature changes. It may also affect the mechanical and durability properties of the construction elements by corrosion.28 The last method, encapsulation, involves adding PCM-filled pellets during the manufacturing of the wallboard. It is less efficient than the other PCM methods due to its low surface area to volume ratio: however, it is quite appealing to designers and contractors because of its ease of application and flexibility as well as its potential to be used in retrofitting projects. Some manufacturers have begun to consider bio-based PCMs, which are organic and not harmful to humans. One example is BioPCM, produced by a company called Phase Change Energy Solutions. It is a non-toxic, non-corrosive product derived from sustainably sourced plant-based byproducts. According to product information, a 7.6 mm layer of BioPCM can store approximately as much heat as a 406 mm-thick block of concrete of the same footprint.29 The manufacturer claims that its product can produce a consistent energy reduction on an HVAC load, in the 25–35% range, by reducing temperature fluctuations, which utilizes the latent heat in the product. Furthermore, the payback period

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Advanced building materials and systems Figure 6.4 University of Washington, Molecular/Nano Engineering Building30

on most of its projects is three years or less. One of its products, the Energy Blanket, was used in the construction of the Molecular Engineering Building at the University of Washington (Figure 6.4), where it was placed in cavities above each floor to absorb the heat from solar gain, electronics, and people. During the night, the building system activates the louvers and ventilation fans together to dissipate the heat absorbed during the daytime by funneling it outside. This allows the PCM to return to its solid stage and the product to recharge and prepare for the next day. The resulting performance has allowed this building to be designed and built without a conventional air conditioning system. The overall energy savings are estimated at $70,000 per year.30

Passive approach: windows PCMs can be used in solid wall, roof, and ceiling panels, and can also be integrated into window systems. The European company GLASSX has developed a window solution by incorporating PCMs into glazing. The key technology uses a thin layer of translucent PCM; at room temperature, 16 mm of this material can absorb as much heat as 250 mm of concrete wall, based on the information from its website.31 Because of its translucency, the product meets the specific VLT value required for a window system while also reducing heat gain. GLASSX has two products: GLASS®crystal and GLASS®store (Figure 6.5). GLASS®crystal (Figure 6.6) has a triple insulating glazing unit that provides a U-value of 0.48 W/m2K. This product is composed of two glass insulating units (GIUs). A prismatic filter is suspended in the outer GIU that reflects higherangle sunlight with excessive solar heat back out, functioning as a passive solar control mechanism for the south-, west-, and east-facing façades. After the lower-angle sunlight passes through the outer GIU, it will enter the inner GIU, which is filled with sealed polycarbonate channels capturing a translucent salt

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Advanced building materials and systems Figure 6.5 GLASS®crystal details31

Figure 6.6 GLASS®crystal details31

hydrate PCM. During hot summer days, the PCM will change phases from solid to liquid to store the heat. Its heat storage capacity is close to 200 mm of concrete. Then, during the nighttime, the heat will be released back to the outside air, and as the GIU cools down, the PCM will return to its solid stage. The direct-beam light transmission reaches up to 45% when the PCM is liquid and up to 28% when the PCM has crystallized.26 Overall, the entire assembly has a width of just over 79 mm weighs about 95 kg/m2, and is more costly than GLASS®store. GLASS®store has one GIU, is lighter, and has a lower thermal storage capacity. GLASSX has completed many projects in Europe, and entered the North American market in 2010. One of the largest projects was the Centre Professionelle school in Fribourg, Switzerland. It used GLASS®store that was mounted 5–10 cm behind the curtain wall, allowing the architect full freedom in designing the façade (Figures 6.7 and 6.8).

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Advanced building materials and systems Figure 6.7 Exterior façade of Centre Professionelle school in Fribourg, Switzerland31

Figure 6.8 Interior view of Centre Professionelle school in Fribourg, Switzerland32

Active: thermal storage for cooling and heating systems A PCM wall can also be combined with the ventilation system, functioning as one active system. One of the main applications is the use of free cooling, where the PCM is installed in the ventilation space between the floor slab and ceiling. During nighttime, the system is charged by the cool outdoor temperatures, and

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the stored cold air is later discharged when the cooling demand rises during the daytime (see Figures 6.9a and 6.9b). A potential technical challenge is to ensure the PCM achieves full solidification in certain climate conditions where the temperature does not drop too far below the phase-change range.32 Not only can this Figure 6.9a PCM ceiling (by Emma Weber and author)

Figure 6.9b PCM ceiling (by Emma Weber and author)

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cooling principle be used in the ceiling system, it can also be applied to the floor deck. The cool deck is a commercially available system that combines the use of night ventilation with thermal storage in the building mass and PCMs. Another method to integrate a PCM into an active system is to use the material in a thermally activated building façade system, such as double-skin ventilated façades. Ventilated façades function well in terms of both cooling and heating loads. As shown in Figure 6.10, the cooling ventilated façade could have four different operational models: 1

2

3

4

The internal heated air passes through the double skin, and the PCM absorbs the excess heat and decreases the air temperature. The cool air can then be circulated back into the room (see Figure 6.10a). During the natural ventilation mode, the warm outside air passes through the double skin first before entering the room. The heat is absorbed by the PCM, and cooler air can circulate through the room (see Figure 6.10b). When the outside air quality is questionable due to high contamination in the summertime, then it only circulates through the outer layer of the double skin while the openings are shut off. The heat will still be absorbed by the PCM; furthermore, reducing the ambient air temperature adjacent to the building can reduce the cooling demand as well (see Figure 6.10c). When the outside air is contaminated during wintertime, both openings are kept closed. The ambient heat will be absorbed by the PCM, causing the entire façade to function as a thick insulation material. Figure 6.10a PCM integrated in double-skin façade mode one (by author and Emma Weber)

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Advanced building materials and systems Figure 6.10b PCM integrated in double-skin façade mode two (by author and Emma Weber)

Figure 6.10c PCM integrated in double-skin façade mode three (by author and Emma Weber)

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Responsive materials and systems Smart systems/materials and intelligent buildings are not creations of the past ten years. The concept can be traced back to the use of thermal expansion materials in sprinkler heads in 1874. Henry Parmelee invented the automatic fire sprinkler system, which used solder that melted in a fire to activate the water pipes, protecting his piano manufacturing business. Solder is a fusible metal alloy—the ancestor of today’s smart materials—that can change either its shape or phase in response to different temperatures, pressures, or other factors. In practice, architects and engineers describe a smart material or object as a product or device that possesses a certain level of intelligence and can respond to outside stimulants—for example, a smart window. These smart products are often composed of multiple layers and types of individual materials that serve specific smart functions together. Below, we examine two types of smart systems/ materials. Type 1 is a responsive system that changes properties in response to a wide range of external and internal ambient condition changes, including the lighting level, magnetic field, temperature, and humidity. Depending on the chemical compound, a smart responsive material will change its chemical, mechanical, optical, electrical, or thermal properties. In this sense, a phase-change material can be described as a smart material. Type 2 is a transduction system that transforms energy from one form to another through a smart material or product. Piezoelectric materials are one such type, where squeezing certain crystals or metals can make electricity flow through them. Common piezoelectric devices includes piezoelectric speakers used for cell phones and piezoelectric ignitors for gas stoves and hobs.

Type 1: responsive materials There are different classes of responsiveness. One of the earliest classes that appealed to designers and engineers was “color changing.” Materials change color in response to exposure to light (photochromic), temperature change (thermochromic), external forces and stress (mechanochromic), and chemical (chemochromic) and electrical environments (electrochromic). Below, we will focus on photochromic, thermochromic, and electrochromic materials’ properties and their ability to improve building energy efficiency.

Color changing: photochromic paint Photochromic materials absorb incoming electromagnetic energy in the ultraviolet region to produce an intrinsic property change that is known as color changing.33 This type of material has been integrated in automobile paint to produce colorchanging cars. The material changes between absorptive and reflective depending on the incident energy; consequently, the appearance and reflectiveness of the product changes as well. The molecules used in photochromic dyes are typically colorless before the incident energy stimulus. When the dye or particles are exposed to light of a certain wavelength, the molecular structure changes to an active state, which allows a certain wavelength of light to pass through while blocking others. Fundamentally, the incident energy (from the sun) produces an

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altered molecular structure of the material’s surface which the light strikes. The perception of the color characteristic depends on the type and wavelength amount of the light being absorbed, reflected, and scattered. Consequently, changing the base structure produces a different absorption and reflectance, which can change the color appearance of an object. The actual energy-saving advantage is not the change in color, but the reflectance of solar radiation. This photochromic colorchanging paint can be applied to the interior or exterior paint of buildings to detect thermal bridges or a leaks.

Electrochromic windows: smart windows An electrochromic window can darken or lighten a room in response to a low voltage, then revert to its original state once the voltage is removed. There are three main classes of materials that change color when electrically activated: electrochromic materials, liquid crystals, and suspended particles.34 The science behind the color change in an electrochromic material is as follows: at the surface of the material, a chemical reaction induces a reversible material change at the molecular level, resulting in the color of the material or product changing. There are quite a few smart windows on the market that use this technology. For example, SageGlass manufactures dynamic glass with a special electrochromic coating that has the potential to significantly reduce the heating and cooling energy required by a building.34 Typically, such window assemblies are composed of three layers: an ion storage layer, an ion-conducting layer, and an electrochromic layer. In SageGlass assemblies (Figure 6.11), the electrochromic layer (Sage coating) is on the inside surface of the outboard laminated lite, which is made of tungsten oxide (WO3). When a low voltage moves into the electrochromic layer, the hydrogen or lithium ions are driven there. This changes the optical properties of the glass, causing it to appear darker. More importantly, the electrochromic change causes the glass to absorb light and solar radiation. The progress can be undone by reversing the voltage and driving the ions out of the electrochromic layer and in the opposite direction.34, 35

VO2 thermochromic smart windows Thermochromic materials absorb heat, which leads to a thermally induced chemical reaction or phase transformation.34 These materials have many different forms, such as liquid crystal, which can be applied as a thin film on the surface of existing products. VO2 is a monoclinic crystalline structure that undergoes a reversible metal–semiconductor transition at a critical temperature of 68 °C.36 When exposed to infrared light, VO2 turns into a tetragonal crystalline structure that is metallic and reflective, which blocks solar infrared radiation, thus helping to regulate the cooling load.

Type 2: transduction materials Transduction materials transfer energy from one state to another. Our natural and built environments are surrounded by energy fields. Energy exchange

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Figure 6.11  SageGlass35

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always involves material changes at molecular levels to maintain a state of equilibrium. The input energy must be equal to the output energy if there is no energy lost during the transformation. One common example is the photovoltaic panel: its solar cell absorbs photon energy and stores it within the material first. As the panel continues to absorb and store the energy, excess energy in the atoms of the solar cell forces the atoms to move to a higher energy level—possibly that of electricity. Eventually, the photovoltaic panel converts the excess photon energy to electric energy. Other materials also convert energy to different forms; however, the main difference between regular and smart materials is that a smart material is able to recover the internal energy in a more usable form, whereas a regular material most often can only convert other energy types to heat, which is typically not useful. Transduction materials are different from phase-changing materials in the way transduction materials can manage energy flow without changing their physical properties. Therefore, compared to phase-changing materials, transduction materials are more stable. Two transduction materials that have been applied to buildings are light-emitting materials and piezoelectric materials.

Piezoelectric tiles Piezoelectric ceramics or piezoelectric polymers, often referred to as piezoceramics and piezopolymers, when under a mechanical load, will generate electric charges on their surface as result of deformation through changes of charge distribution. The first piezoelectric effect was discovered in 1880 in natural Rochelle salt (potassium sodium tartrate) by the Curie brothers, Pierre and Jacques. They discovered that the electrostatic charge generated from a variety of crystals was proportionally related to the different mechanical loads applied to them. A patent was filed by Walter P. Kistler, followed by several efforts in the 1960s to 1980s to discover the industrial application of this new type of material. In the late 1990s, a Finnish firm developed a quasi-piezoelectric electret film, which is mainly used for sensors in a number of different applications other than buildings.1 Currently, piezoelectric applications include piezoelectric tiles (Figure 6.12) that convert kinetic energy to electricity and piezoelectric generators that can power light-emitting diodes (LEDs) from the energy of raindrops. PAVEGE is a flooring system used in 150 projects worldwide: as people

Figure 6.12 Piezoelectric tile38

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step on the tiles, their weight causes electromagnetic induction generators to vertically deform. This results in a rotatory motion that creates electricity which can be used power household appliances or lighting fixtures.37

Light-emitting materials: LED lighting Light-emitting materials are the most commonly used transduction materials in the building industry. The light is caused by re-emission of energy in wavelengths in the visible spectrum, and is associated with the transition of electrons from a higher energy state to a lower energy state.34 There are three subsets of materials that can emit light via transition of electrons from a higher energy state: photoluminescense, chemoluminescense, and electroluminescense. An LED is made of electroluminescent materials—semiconductors that release the lower-level energy (light wavelength) caused by general movement of the electrons within the materials. Photoluminescent materials require excitation by external light acting upon the material; standard fluorescent lamps are, in fact, based on photoluminescent effects. Bioluminescent light is a subset of chemoluminescent light that has great potential. It can provide glow using the mechanism found in a variety of light-emitting insects, such as fireflies, jellyfish, and other bacteria. The bioluminescent light is self-energizing, self-reproducing, and self-maintaining. One of the largest lighting manufacturers, Philips, conducted an experimental project in 2011 named Microbial Home, where the designers and researchers tried to create a domestic closed-loop ecosystem that could challenge conventional modern architectural design and construction solutions to water, energy, food source, lighting, and waste management. They designed and produced a “biolight,” which used bioluminescent bacteria that were fed methane gas from human waste. The biolight produced very soft green lighting when fed through silicon tubes.39, 40 As an experiment, it was very promising; however, as a practical lighting fixture, it still requires great improvement.

Conclusion We use smart technologies in our daily life (smartphones, smart sensors, and voice-activated systems), and a smart built environment takes full advantage of the potential of smart sensors, smart materials, and other innovative building systems that adapt to the needs of occupants and dramatic external climatic events. Smart buildings signify a leading role in the transformation of the existing built environment by turning buildings into environmentally responsive, user-focused, health-conscious, and interconnected systems. In general, these smart materials and systems will enable a better living and working environment for the occupants. Currently, many items in our home can be connected to the Internet, programmed, and remotely controlled: smart lights remember our preferred lighting levels, smart thermostats automatically adjust the room temperature, and smart refrigerators encourage us to eat healthier. Smart technologies have made our lives more convenient than ever; while these smart materials and systems are promising, they also present challenges. For instance, the Arab World Institute

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building, designed by Jean Nouvel in 1987, was equipped with an advanced responsive metallic sun shade (shutter) on the south façade. The system integrated several hundreds of light-sensitive diaphragms that were used to regulate the amount of daylight admitted into the building. In theory, the façade could change according to different light intensities and angles. However, the occupants found the repeated and constant adaptation somewhat distracting: the changes took place at short intervals and sometimes even under a heavily overcast sky. To solve the problem, the smart system was calibrated to be less sensitive and responsive—to be less smart. Therefore, to appropriately apply smart materials and systems in buildings, the first step is to properly inform design professionals and the public of these smart technologies, including their advantages, disadvantages, and potential applications. Through awareness and educated application, these smart materials and systems can play a positive and essential role in transforming the built environment into one that is highly efficient, smart, and healthy.

Note i Eutectic indicates a mixture of substances that has a low freezing point.

References 1 Ritter, Axel. Smart Materials in Architecture, Interior Architecture and Design. Walter de Gruyter, 2007. 2 “Nanotechnology 101.” Nano.gov National Nanotechnology Initiative. Accessed January 2, 2019. www.nano.gov/ 3 Feynman, Richard P. “There’s plenty of room at the bottom: An invitation to enter a new field of physics.” Caltech Engineering and Science 23, no. 5 (1960): 22–36. Lecture delivered at annual meeting of American Physical Society at California Institute of Technology, December 29, 1959. Accessed January 2, 2019. www.zyvex.com/nanotech/feynman.html 4 Leone, Mattia Federico. “Nanotechnology for architecture: Innovation and eco-efficiency of nanostructured cement-based materials.” Journal of Architectural Engineering Technology 1, no. 1 (2012): 1. 5 Hu, Ming. “The significance of nanotechnology in architectural design.” Journal of Architectural Research (2015): 90. Accessed January 2, 2019. http://www.brikbase.org/sites/default/files/ARCC2015_54_hu.pdf 6 “NNI Supplement to the President’s Budget.” Nano.gov National Nanotechnology Initiative, November 30, 2017. Accessed January 2, 2019. www.nano.gov/2018BudgetSupplement 7 Connolly, Richard. “State industrial policy in Russia: The nanotechnology industry.” Post-Soviet Affairs 29, no. 1 (2013): 1–30. 8 Nanotechnology: The Invisible Giant Tackling Europe’s Future Challenges. European Commission, 2103. Accessed January 2, 2019. https://ec.europa. eu/research/industrial_technologies/pdf/nanotechnology_en.pdf 9 Kistler, Samuel Stephens. “Coherent expanded aerogels and jellies.” Nature 127, no. 3211 (1931): 741. 10 Kistler, S. S., and A. G. Caldwell. “Thermal conductivity of silica aerogel.” Industrial & Engineering Chemistry 26, no. 6 (1934): 658–662.

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11 Cuce, E., P. M. Cuce, C. J. Wood, and S. B. Riffat. “Toward aerogel based thermal superinsulation in buildings: A comprehensive review.” Renewable and Sustainable Energy Reviews 34 (2014): 273–299. 12 Baetens, Ruben, Bjørn Petter Jelle, and Arild Gustavsen. “Aerogel insulation for building applications: a state-of-the-art review.” Energy and Buildings 43, no. 4 (2011): 761–769. 13 “Sculpture Building and School of Art Gallery.” Kieran Timberlake Architects. Accessed January 2, 2019. https://kierantimberlake.com/pages/view/9 14 Davies, J. Clarence. Nanotechnology Oversight: An Agenda for the New Administration. Woodrow Wilson International Center and Pew Charitable Trust, July 2008. Accessed January 2, 2019. www.nanotechproject.org/ process/assets/files/6709/pen13.pdf 15 Mann, Surinder. “Nanotechnology and Construction,” nanoforum.org European Nanotechnology Gateway, October 31, 2006. Accessed July 20, 2018. https://nanotech.law.asu.edu/Documents/2009/10/Nanotech%20 and%20Construction%20Nanoforum%20report_259_9089.pdf 16 Del Monte, Louis A. Nanoweapons: A Growing Threat to Humanity. University of Nebraska Press, 2017. 17 “Industrial applications of nanotechnology.” Wikipedia. Accessed January 2, 2019. https://en.wikipedia.org/wiki/Industrial_applications_of_nanotechnology 18 Kosny, Jan, Nitin Shukla, and Ali Fallahi. Cost Analysis of Simple Phase Change Material-enhanced Building Envelopes in Southern US Climates (no. DOE/GO--102013-3692). Fraunhofer CSE, 2013. 19 Sharma, Atul, V. Veer Tyagi, C. R. Chen, and Dharam Buddhi. “Review on thermal energy storage with phase change materials and applications.” Renewable and Sustainable Energy Reviews 13, no. 2 (2009): 318–345. 20 Benson, David K., C. B. Christensen, and R. W. Burrows. New Phase-change Thermal Energy Storage Materials for Buildings (no. SERI/TP-255-2727; CONF-850905-5). Solar Energy Research Institute, 1985. 21 Baetens, Ruben, Bjørn Petter Jelle, and Arild Gustavsen. “Phase change materials for building applications: a state-of-the-art review.” Energy and Buildings 42, no. 9 (2010): 1361–1368. 22 Bruno, Frank. Using Phase Change Materials (PCMs) for Space Heating and Cooling in Buildings. Airah Publications, 2004. 23 Athienitis, A. K., C. Liu, D. Hawes, D. Banu, and D. Feldman. “Investigation of the thermal performance of a passive solar test-room with wall latent heat storage.” Building and Environment 32, no. 5 (1997): 405–410. 24 Kauranen, P., K. Peippo, and P. D. Lund. “An organic PCM storage system with adjustable melting temperature.” Solar Energy 46, no. 5 (1991): 275–278. 25 Rudd, Armin F. “Phase-change material wallboard for distributed thermal storage in buildings.” Transactions of the American Society of Heating, Refrigerating and Air Conditioning Engineers 99 (1993): 339. 26 Kedl, R. J. Conventional Wallboard with Latent Heat Storage for Passive Solar Applications (no. CONF-900801-14). Oak Ridge National Laboratory, 1990. 27 Feldman, D., M. A. Khan, and D. Banu. “Energy storage composite with an organic PCM.” Solar Energy Materials 18, no. 6 (1989): 333–341.

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28 Cui, Yaping, Jingchao Xie, Jiaping Liu, and Song Pan. “Review of phase change materials integrated in building walls for energy saving.” Procedia Engineering 121 (2015): 763–770. 29 “What is BioPCM®?” Phase change energy solutions. Accessed January 2, 2019. www.phasechange.com/technology 30 “University of Washington, MoIES and NanoES Buildings.” ZGF Architects. Accessed January 2, 2019. www.zgf.com/project/university-of-washingtonmolecular-engineering-sciences-building/ 31 GLASSX. Accessed January 2, 2019. www.glassx.ch 32 Addington, Michelle, and Daniel Schodek. Smart Materials and Technologies in Architecture: For the Architecture and Design Professions. Routledge, 2012. 33 “Q&A: Dr. Sabine Hoffmann, Technical University of Kaiserslautern (Germany).” SageGlass, October 19, 2017. Accessed January 2, 2019. www.sageglass. com/en/qa-dr-sabine-hoffmann-tech-university-kaiserslautern 34 “Dare to be innovative.” SageGlass. Accessed January 2, 2019. www.sageglass. com/en 35 “Dynamic products drive dynamic spaces.” SageGlass. Accessed January 2, 2019. www.sageglass.com/en/products 36 Zhou, Jiadong, Yanfeng Gao, Zongtao Zhang, Hongjie Luo, Chuanxiang Cao, Zhang Chen, Lei Dai, and Xinling Liu. “VO 2 thermochromic smart window for energy savings and generation.” Scientific Reports 3 (2013): 3029. 37 “How does the Pavegen technology work?” Pavegen. Accessed January 2, 2019. www.pavegen.com/about/ 38 Kinetic Tiles. Accessed January 2, 2019. https://kinetictiles.wordpress.com/ tag/piezoelectric-floor-tiles/ 39 Asuncion, Isabel Berenguer. “Bioluminescence and the future of lighting,” Inquirer.net, October 20, 2012. Accessed January 2, 2019. http://business. inquirer.net/88268/bioluminescence-and-the-future-of-lighting 40 Knight, Matthew. “Glowing bacteria could power ‘bio-light.’” CNN Business, December 3, 2011. Accessed January 2, 2019. www.cnn.com/2011/12/03/ tech/innovation/bio-light-eco-system/index.html

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Chapter 7

Zero impact building New framework based on life cycle assessment

Problems of existing net zero definitions In recent years, there have been efforts to expand the definition and scope of net zero building to incorporate larger ecological concerns and treat buildings as part of the bigger urban context instead of as isolated cases. For instance, in 2015, the US National Institute of Building Science prepared a report for the US Department of Energy regarding the common definition of zero energy buildings. In this report, they proposed two expanded definitions: a zero energy community and zero energy campus. Based on the proposed definition, a zero energy campus is an energy-efficient campus where, on a source energy basis, the actual delivered energy is less than or equal to the onsite renewable exported energy. A zero energy community is an energy-efficient community where, on a source energy basis, the actual annual delivered energy is less than or equal to the onsite renewable exported energy.1 Despite such an expanded scope, existing net zero definitions are still very much focused on the operating energy, meaning the energy consumed by occupants during a building’s service life span. However, there are several missing components in such an approach, which are detailed below.

Missing component one: embodied energy Most current definitions of net zero building and building energy codes and regulations address the building’s operating energy, which is associated with the energy used for lighting, heating, cooling, ventilation, equipment, and appliances. Research into reducing the operating energy and its related greenhouse gas emissions has stimulated practice changes in the building industry as described in Chapters 3 and 5. Meanwhile, concerns regarding embodied energy and related greenhouse gas emissions from buildings still need to be incorporated into design guidelines and building regulations. Embodied energy is the energy needed to construct and maintain a building during all processes of production, onsite construction, and final demolition and disposal. The majority of embodied energy is expended once—in the initial construction stage of

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building. Embodied energy accounts for a significant portion of the total life cycle energy2, 3, 4 and can be reduced by decreasing the building footprint, using fewer energy-intensive materials, and optimizing design strategies. Overall embodied energy consists of two primary categories: direct embodied energy (DEE) and indirect embodied energy (IEE). Direct embodied energy is the energy consumed on- and offsite for building activities, such as construction, onsite prefabrication, transportation, and other related activities. Indirect embodied energy is the energy consumed in manufacturing building materials and assemblies as well as in repair and maintenance. There are several types of IEE, including indirect initial embodied energy (IIEE), which is the energy used during the initial manufacturing activities, indirect recurring embodied energy (IREE), which is used in maintenance and repair during the building’s useful life span, and indirect demolition energy (IDE), which refers to the energy spent during the process of a building’s deconstruction and disposal of building materials.5 The life cycle embodied energy (LCEE) can be calculated using the proposed Equation 7A: c=1

LCEEb = DEEb + ∑c = end (IIEEc + IREEc + IDEc) × BTc

(Equation 7A)

where LCEEb is the life cycle embodied energy demand of a building, DEEb is direct energy, IIEEc is indirect initial embodied energy, IREE is indirect recurring energy (maintenance and repair), and IDEc is the indirect demolition energy. C=end represents the end of the building’s life span. BTc is the building type factor; certain building types needs more frequent maintenance and repair than others, such as those with swimming pools.

Missing component two: occupants’ transport energy Most building occupants commute daily to and from work. Transport energy is associated with the mobility of building users. The total transport energy of a building’s occupants is calculated based on their annual travel distance and the total energy intensity of the transport models they use (e.g., bike, car, bus). There is much discussion on whether allocating occupants’ transport energy solely to the building can correctly represent real conditions. Some researchers argue that the destination location is not the sole driver of users’ transport energy consumption and that the location of other supporting buildings—such as daycare centers, healthcare facilities, and grocery stores—also affect travel distances.6 How to allocate the users’ transport energy is affected by many different factors and is a highly subjective topic. In this book, the author adopts a method that allocates occupants’ transport energy to the dwelling where the occupant lives or works for the following reasons: in normal conditions, a dwelling is the destination or origin of most trips; also, the dwellers are the ones consuming energy on their commute.6 Once we determine how to allocate transport energy, we can calculate the energy spent by dwellers on

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their commute. The life cycle transport energy (LCTE) demand can then be calculated according to Equation 7B: c

LCTEb = ULb × ∑ c = 1(DEIc + IEIc) × ATDc

(Equation 7B)6

where LCTEb is the life cycle transport energy demand of the occupants of a building, ULb is the useful (service) life of the building (normally 60 years), and DEIc is the direct energy intensity related to the mobility process itself, such as fuel consumption. DEIc can be determined based on vehicle mileage per gallon (MPG) or kilometers per liter. Fuel consumption information can be found either from the manufacturer or a third-party database, such as the US Department of Energy’s Office of Energy Efficiency and Renewable Energy. IEIc represents the indirect energy intensity of the transport mode related to other processes supporting the mobility: for instance, car registration insurance, maintenance, etc. ATDc is the average annual travel distance per building (in miles or meters). The travel distance can be acquired from a post-occupancy survey, or if a survey is difficult to conduct, regional census data can be used. Transport energy is not only defined by an individual’s behavior and lifestyle—it is also determined by the larger urban context. For dense urban areas, where public transportation is easily accessible, a user will likely choose to use public transportation, which has a much lower transport energy intensity than automobiles. Therefore, reducing transport energy requires a holistic planning approach. Centralized job opportunities allow proximity between companies, which could reduce the need for collaboration-related travel (for meetings), and mix-used developments provide a working and living environment where workers do not need to travel far. These planning approaches can only be undertaken at a regional planning level.

Missing component three: induced energy and other factors Induced impact is defined as the fringe social and economic impacts from the interaction between individual buildings and their surrounding urban context. For instance, the construction of a masonry building that utilizes local materials and workers can result in the total building cost being paid in local wages as opposed to using curtain wall glass and paying for industrially processed materials.7 Also, employing local workers will promote development of the local economy. Construction activities have a ripple effect on the local economy and microenvironmental conditions, while energy consumption and its impact typically induced by buildings and built environments are difficult to quantify. Due to its complexity, the author does not propose a quantitative method to assess the induced energy demand in this book.

Life cycle energy assessment The entire life cycle of a building consists of five stages: (1) raw material extraction, (2) manufacturing of building products, (3) onsite construction, (4) occupancy and maintenance, and (5) demolition and reuse (see Figure 7.1).

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Zero impact building Figure 7.1 Life cycle assessment of building

Figure 7.2 Life cycle energy assessment

The life cycle energy consists of embodied, operating, transport, and induced energy over the entire building life cycle (see Figure 7.2).

Additional impact indicators As mentioned in the previous section, most current net zero building definitions share a similar framework and measurement mechanism involving energy consumption. This shared framework allows the concept to be understandable and translatable. Reducing energy consumption in building is essential to achieving the overall climate change mitigation target. The challenges of finding a collective framework to define zero impact building (ZIB) are due to the fact that, unlike energy, ZIB impacts many different categories, such as air, water, land, the

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environment, and health, which will be discussed below. Different impact categories call for different criteria and measurements, and a holistic framework is needed to integrate them all. Following the same process as net zero building, setting a consistent framework to define ZIB is the first critical step to achieving the carbon-neutral development goal.

Zero impact on land use Buildings affect the natural ecosystem in a variety of ways. Urban sprawl has already created a profound environmental impact that is irreversible, especially in the United States. We are using land faster than it can self-regenerate, and the impacts—such as the urban heat island effect, storm water runoff, and surface temperature increase—have become common problems that modern cities face, both in developing and developed countries. The impact on land use consists of two elements. The first element involves quantitative impacts, which are included in most urban land use and design guidelines. These guidelines concern land spatial coverage, housing density, mean housing, and plot size and function. The impacts associated with these factors can be measured and monitored or altered. The second element is qualitative impact, which involves the adaptations of buildings to the existing ecosystem, including the management of site water, urban heat island effect, pollution, and other microclimatic factors.8 The qualitative impact can be measured by comparing it to the baseline or universal benchmark. A net zero impact building can minimize the impact on land by reducing the building’s footprint and improving the site’s microclimate conditions through ecological site design techniques. These techniques include minimizing new impervious surfaces (e.g., parking lots and traffic lanes), providing wildlife corridors or habitats (e.g., green roofs and gardens), controlling erosion or sedimentation, reusing brownfield sites, retrofitting existing buildings instead of building new, and incorporating transportation solutions into site planning.

Zero impact on the environment Regarding the environment, the influence and consequences of building can be divided into two categories: the macro and micro level. At the macro level, the materials and construction methods used to construct a building significantly contribute to the building’s overall environmental impact. Greenhouse gas emissions released through energy used to produce and transport building assemblies to building sites have a global effect. At the regional level, construction activities, such as quarrying, have a deep impact on the local ecosystem and are irreversible. Overall, globally, the building industry is responsible for high levels of pollution as a result of the energy consumed during extraction, transport, and manufacturing of raw materials, transportation and construction,7 and the entire life cycle of a building. At the micro level, urban and building designs shape and alter the local environment. The layout and configurations of buildings cause variations in

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the microclimate from one location to another. The climatic characteristics of neighborhoods are influenced by urban fabric and texture through design. For example, in a comparison of low-rise and middle-rise/high-rise building neighborhoods, the microclimate of those areas is altered by design strategies. High-rise buildings block direct solar radiation and reduce the potential utilization of solar energy, but can decrease wind permeability by blocking predominant winds. Another commonly used building design strategy is to integrate green roofs and outdoor landscapes, which can help to cool ambient air, especially where traffic heat sources are present.9

Zero impact on water Water is another scarce resource during a building’s life cycle; it is required from raw material extraction to the building’s operation. Water use efficiency is a key metric in measuring the sustainability of a building. Some green building rating systems have incorporated water as an important indicator for measuring the impact of building. For example, the Living Building Challenge has a category for net water, and LEED also sets aside credits for water conservation. So far, the focus has been on measurable water conservation (quantitative measurement); however, the energy costs and carbon emissions associated with obtaining water need to be incorporated into the water life cycle within buildings. In addition, improvements or decreases in the quality of water are important elements to be considered, as construction activities could increase the potential acidification and eutrophication onsite.

Zero impact on health According to the World Health Organization, “Urbanization is one of the leading global trends of the twenty-first century that has a significant impact on health.” It is expected that by 2050, nearly three-quarters of the world’s population will reside in an urban environment. With urbanization and population growth, city life has become a reality for most of the global population, in addition to increased health risks that accompany urban spaces and settings. Some of these risks include air pollution, poor urban sanitation, substandard housing, green space scarcity, congestion, and violence. Likewise, physical and mental urban health issues have expanded beyond traditional morbidities to include infectious and chronic diseases while also identifying the social (e.g., social support, residential segregation, and transportation options) and physical (e.g., natural and built environments and housing and community design) determinants of health. Buildings are essentially human habitats, and built environments that contain essential features of preferred natural settings will be more supportive to humans’ wellbeing and daily performance than environments that lack these features.10 These preferred features include indoor parks, water features, daylight, and multiple views. Health impacts from the built environment can be categorized as physical and psychological impacts that can be measured by ability, motivation, and opportunity (see Table 7.1).

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Impact

Excessive nutrient enrichment causes undesirable shifts in species composition in aquatic ecosystems

Carbon emissions

NOx and VOCs generated in the presence of sunlight lead to lung damage and other impacts on the ecosystem

Primary sources of ozone precursors are electricity generation and motor vehicles

Global warming potential

Smog potential

Ozone depletion potential

Emissions lead to acidifying effects on the environment

Eutrophication

Acidification

Quantity

Induced energy

Transport energy

Energy/emissions related to generating clean water, treating grey/black water

Energy consumption and carbon emissions

Embodied energy

Operating energy

Negative impact

Sub-categories

Table 7.1  Impact categories and measurement units

Quality

Water

Macro

Energy

Environment

Reduce energy consumption

Use less harmful materials and optimize construction methods

Reduce energy consumption

Use less harmful materials and optimize construction methods

Reduce carbon emissions

Capture rainwater onsite

Use low-impact materials

Capture rainwater, recycle and reuse grey and black water

Renewable energy generation onsite

Mitigation

kg CFC eq/m2

kg O3 eq/m2

(continued)

GHG emissions per unit floor area (metric tons/m2)

kg N eq/m2

Measurement of increase in hydrogen ion (H) concentration in the water (kg SO2 eq/m2)

Liters per floor area (liters/m2)

Average GHG emissions per unit floor area (metric tons/m2)

Measurement

Enable occupants to perform certain tasks

Assess whether a person is willing to perform a certain task

Provide conditions that reduce health and safety risks

Ability

Motivation

Opportunity

Quantify the biodiversity of an urban habitat (building site)

Speed difference between the building site and the unbuilt site

Wind flow

Biodiversity

Temperature difference between the building site and the city average

Negative impact

Heat island effect

Sub-categories

Micro

Impact

Table 7.1  (continued)

Health (physical and psychological)

°C parts per million (ppm) Indoor environmental quality (scale 0–10)

Thermal comfort Cleanness Air quality

Create a healthy, friendly indoor environment

Indoor habitat quality (scale 0–10)

Personal control

Accessibility to views

Indoor spatial quality (scale 0–10)

decibel (dB)

Create a good environment for high productivity and enhance social interaction

lux (Lx)

Nose level

Simpson index of diversity (0–1)

m.p.h. or m/s

°C

Measurement

Light level

Use landscape design to create habitats for diverse species

Use building massing, design to optimize wind flow

Vegetated roof (cool roof), use less reflective exterior material

Mitigation

Zero impact building

Proposed definition of net zero impact building from a life cycle perspective In this book, a zero impact building is a building that has no negative environmental or human health impacts. A ZIB balances the raw resources drawn from the natural environment (land, energy, and water) with its positive contribution to the natural environment at a local site over a specified period. The local site could be a building site, block, or entire community. Figure 7.3 presents a suggested zero impact building definition framework. A zero impact building consists of four main categories: energy, water, environment, and health. A building must have a neutral impact on all four categories to qualify as a true zero impact building. In the energy category, there are four subsets: embodied energy, transport energy, induced energy, and operational energy. In the water category, there are two subsets: water conservation quantity and water quality. In the environment category, macro-level and micro-level impacts are included. The macro-level environment includes the potential for global warming, ozone depletion, and smog formation while the micro level focuses on a building’s impact on microclimate conditions, such as the heat island effect, and micro water systems such as storm water runoff. Lastly, the health category considers physical and psychological impacts due

Figure 7.3 Suggested definition of framework (by Emma Weber and author)

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to buildings. Negative physical impacts of buildings, such as sick building syndrome, can cause headaches, sore throats, stinging eyes, and respiratory-related problems. Furthermore, the physical setting and design layout and features can influence occupants’ psychological well-being.

Proposed evaluation framework for net zero impact building To achieve the zero impact goal, an ecological approach is needed. Ecological design strategies view a building as an active subject in contributing to urban sustainability, rather than just as a resource and energy consumer. The most promising ecological approach in built environment research is the life cycle approach. The suggested zero impact building evaluation framework is composed of four life cycle assessments (LCAs), which are compatible with the four impact categories mentioned in the previous section. The four assessments are the life cycle energy assessment (explained earlier in this chapter), life cycle water assessment, life cycle environmental impact assessment, and life cycle health assessment. The direct input includes all conventional and new attributes at the building scale, such as materials, types, operational schedules, maintenance schedules, renovations, and upgrade potential. The indirect input includes all induced and related factors at the urban scale: the building location, urban and cultural context, development density, infrastructure readiness, occupants’ behaviors, and other human factors. After conducting the four assessments, the results are aggregated into comparable and consistent measurement units (see Table 7.1), and the negative impacts and positive trade-offs are quantified. The output from the four categories will be converted to three impact categories: environmental (environment and water), economic (energy, water, and health), and social (health and energy). The three impact categories are then evaluated by an analysis of three different scenarios. The final outputs will be interpreted and used to evaluate whether an existing or future building at a specific site can qualify as a net zero impact building. The evaluation may result in using feedback to determine downstream project planning and implementation, influence policy and regulation changes, or promote social change (see Figure 7.4).

Brief introduction to the life cycle assessment Life cycle assessment is a framework or methodology used to measure and estimate the environmental impact of a product throughout the product’s entire life span. Since 1990, the LCA has been recognized and employed as an important environmental assessment method in the building sector.11 Sometimes, LCAs are referred to as “cradle to cradle” assessments. In international standardization, the ISO 1404012 series defines the principles and framework of life cycle assessment, and ISO 1404410 provides detailed procedural requirements and guidelines for conducting an LCA.13 The first step in conducting an LCA is to define the scope and goals, function units, and boundaries of the study. The second step is to select the appropriate life cycle inventory (LCI), which is a database collecting all relevant inputs and outputs of a product’s life cycle.14 The third step, the life cycle impact assessment (LCIA), translates the input data from the LCI

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Building Location Urban/Cultural Context Development Density Infrastructure Readiness

Figure 7.4  Suggested analysis framework

Management

Design/Construction

Policy/Regulation

DOWNSTREAM IMPLEMENTATION

Building Material Operational Schedule Building Type Future Renovation

INPUTS

Direct

Indirect

DECISION-MAKING POLICY INCENTIVE

Life Cycle Health

Life Cycle Water

Life Cycle Environment

Life Cycle Energy

ASSESSMENT (table 1)

Progressive Scenario

Conservative Scenario

Conventional Scenario

SCENARIO ANALYSIS

Social Impact

Economic Impact

Environment Impact

IMPACT CATEGORY

YES

NET IMPACT

NO

Zero impact building Figure 7.5 The methodological framework for an LCA15

to a set of measurements and estimations of potential environmental impacts associated with a product. Lastly, the results from the LCIA will be interpreted to identify critical areas and make relevant recommendations (see Figure 7.5). The quality of an LCA study is directly related to the quality of the input LCI data. North American governments began developing LCI data in the 1990s. Environment Canada funded three LCA data projects, with the first, in 1991, being an investigation of building materials.16 In the mid-1990s, the Canadian “Athena Project” made these data available as spreadsheets, and in 2002, the data were converted into what is now called the Athena Impact Estimator for Buildings (IE4B). In the United States, the Department of Energy’s most significant involvement in LCAs is currently via the National Renewable Energy Laboratory (NREL) hosting the US Life Cycle Inventory (LCI) Database. The Department of Energy and, more recently, the US Department of Agriculture has led the data development. The NREL created the US LCI Database in 2003, and today it includes 1115 US datasets in a variety of software-compatible formats, representing certain agricultural and wood products, aluminum, iron and steel, logistics, organic and inorganic chemicals, and plastics and resins, among others. So far, this is the largest database of building materials and components that is used in the United States.17 In the past decade, research on LCAs has significantly increased in consumer products and the manufacture of building materials, with considerable focus on the whole building and construction process. Buildings are more difficult to assess due to their complexity, long life spans, and diverse materials. During the past 15 years, energy, material, sustainability, carbon, and technology have been the top five research topics pertinent to conducting an LCA.18 Among them, energy takes the lead, which includes renewable energy, operating energy, and

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embodied energy. For many years, operating energy has been a major focus since reducing operating energy consumption can mitigate the environmental impacts of building. However, in the past ten years, embodied energy—energy associated with a product that covers both the manufacturing and assembly processes—has become the leading topic related to energy, as mentioned in Chapter 5.15, 19 A large portion of the environmental impact of building is embedded in embodied energy. It is important to achieve a balance between operating and embodied energy to reduce energy consumption while decreasing the environmental impact.

Life cycle environmental impact analysis A wide variety of sub-categories contribute to the overall environmental impact of a product or system, including global warming, ozone depletion, smog formation, and eco-toxicity. Given the complexity of the environmental assessment and interactions between the built and natural environment, professionals typically use software packages to conduct assessments—such as Anthena, Simapro, BEES, and most recently, Tally. Tally was developed by KT Innovations (an affiliate of Kieran Timberlake, an award-winning architecture firm based in Philadelphia), together with Autodesk and Thinkstep. Tally enables LCA on demand throughout the Building Information Model (BIM) process. It is the first application for Autodesk Revit® that quantifies the environmental impact of building materials. Tally leverages and extends BIM material takeoff capabilities, accelerating users’ ability to create a realistic bill of materials and gather rapid insights into the ecological trade-offs of different design scenarios.20 With the detailed material and building system information built into the Revit model, Tally can quantify the volume of materials used in the building accurately. Based on detailed information about building materials and construction type, Tally’s results illustrate the percentage effort needed in each environmental category in order to make the building zero impact in environmental terms. For instance, based on Figure 7.6, to enable building with zero impact on acidification potential, we need to reduce the global warming potential from life stage A1-B4 by 39% by using more sustainable materials and reducing operating energy consumption and transportation needs. Tally uses the US LCI Database created by NREL, so the results are reliable, but only applicable in the United States.

Life cycle water assessment The life cycle water assessment includes quantitative assessment (consumption) and quality assessment (acidification and eutrophication). Life cycle water consumption includes the water use for building construction, maintenance, and repairs, along with the water used by occupants during the building’s whole life span (see Figure 7.7). Construction water is composed of direct and indirect construction water. Direct construction water is the water used for raw material extraction, product manufacturing, transport, and onsite construction, while indirect water is the water consumed by other activities associated with construction. Operating water is water used by occupants in a building during its life span

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9,539,784 MJ

9.278E+007 MJ Non-renewable Energy

352,081 O3eq Smog Formation Potential

1.023E+008 MJ

0.2182 CFC-11eq Ozone Depletion Potential

Primary Energy Demand

8,091,703 kgCO2eq Global Warming Potential

1,317 kgNeq

26,687 kgSO2eq

Results per Life Cycle Stage 6,630,619 kg

Figure 7.6 Tally analysis results

100%

50%

0%

Renewable Energy

Eutrophication Potential

Acidification Potential

Mass

−50%

Legend Net value (impacts + credits) Life Cycle Stages Manufacturing [A1-A3]

Transportation [A4]

Maintenance and Replacement [B2-B4]

End of Life [C2-C4, D]

for purposes such as drinking, heating, sanitation, and irrigation. Transportation water is that consumed by occupants during their commute to and from the building. The measurement unit for life cycle water consumption is liters per square meter (or gallons per square foot). Life cycle water quality reflects the acidification and eutrophication potential. Acidification is related to fish mortality and the deterioration of buildings and infrastructure materials. Most recently, scientists have found evidence linking urbanization to soil acidification in China.21 Previously, agricultural activities were the major contributor to the eutrophication of water bodies. In recent years, wastewater has begun to impact urban bodies’ eutrophication, with most of the concentration of nitrogen in wastewater coming from buildings. Figure 7.7 Life cycle water diagram

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Zero impact building

Life cycle health assessment A building that provides high-quality ambient conditions can affect the occupants’ work performance. Ambient conditions are composed of air quality; noise, lighting, dust, and dirt levels; thermal comfort; and view accessibility. Occupants’ motivations to perform may be affected by spatial quality. More precisely, space and building designs can foster or hinder social and psychological engagement and personal control. Motivation measures whether a person is willing to perform a certain task. In an open office layout, occupants are more willing to interact with others, whereas in a private, enclosed workspace, occupants tend to have better concentration and thus are willing to take on more difficult tasks. Lastly, a building can affect opportunity by providing conditions that reduce health and safety risks. For example, a building with low ventilation rates is often reported as being stuffy and unpleasant. The increase in pollutants can cause much harm, with common symptoms including fatigue, sinus congestion, coughing, sneezing, eye irritation, and headaches. The results from the four life cycle assessments are then aggregated and reorganized into three impact categories: environmental, economic, and social impacts, based on the triple bottom line concept. The triple bottom line, a concept frequently used to describe sustainability, was coined by John Elkington in 1994. He argued that the method by which an organization or society measures value should not only include the financial bottom line, but the environmental and social bottom lines as well. The concept has evolved to describe three overlapping circles: economic (profit), environmental (planet), and social (people), and sustainability is often described as representing the place where the three circles

Figure 7.8 Life cycle health assessment diagram

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overlap in the center. When overlaying the four LCAs with the triple bottom line framework, we realize that the multiple categories contribute to each individual bottom line (see Figure 7.4) while each bottom line’s performance is interdependent of the others. The dynamic between different impact categories and bottom lines is complex. Each society has its own different views on sustainability, environmental impact, and risk management, therefore every society values them differently. In order to provide an assessment that is appropriate to a particular society, one can use the technique of scenario analysis.

Scenario analysis Scenario analysis uses a novel weighting system to predict all possible alternative outcomes under uncertainties. Uncertainties represent a major difference between buildings and other consumer products. The weighting system is developed based on personal and social group preference. Personal values—such as personal attitudes, cultural backgrounds, acceptance of risk, and personal beliefs—are deemed as criteria used to make judgments and evaluations, eventually determining the choices people make based on their optimized value to them. Perspectives are used as a tool or framework to cluster different personal values,22, 23 and are rooted in the cultural theory of risk. Cultural theory was developed by anthropologist Mary Douglas, and was originally a social anthropology approach based on the structure and functioning of groups within societies. Any form of society produces its own selected view of the natural environment—a view that influences which threats are worthy of attention.9 Applying a set of views of the natural environment will help us to understand how occupants behave and make important decisions that produce substantial environmental impacts during a building’s use phase. Cultural theory results in five archetypes of people: the egalitarian, hierarchist, fatalist, individualist, and hermit. Each archetype reflects a composition of ideologies, cultural biases, social relationships, moral beliefs, and concerns of interest.9 Douglas argues that the variety of an individual’s involvement in social life can be adequately captured by the two dimensions of sociality: group and grid. Group refers to the extent to which an individual is incorporated into bounded units, whereas grid denotes the degree to which an individual’s life is circumscribed by externally imposed prescriptions.24, 25 The two dimensions together define the five archetypes: an egalitarian has strong group boundaries with minimal prescriptions; a hierarchist is characterized by strong group boundaries and prescriptions; a fatalist is excluded from group decisions, coupled with binding prescriptions; an individualist is defined by neither group incorporation nor prescribed social roles; and a hermit is an individual completely withdrawn from social involvement. These five archetypes can be understood as perspectives used to view and manage the system and deal with risks. A managing system, in a building context, could be interpreted as the initial design/construction and operation and renovation, while risks can be translated to natural or man-made disasters. For instance, during an entire building’s life span, risks could include fire, flooding, leakage, or terrorist attacks. Among the five archetypes, fatalists

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will not request LCAs to support decisions and will not take an active role in decision-making, and hermits withdraw from social involvement altogether.12 Therefore, only the individualist, hierarchist, and egalitarian are active in public decision-making and interested in understanding buildings’ long-term impact. One reason to develop a weighting system with cultural theory is the fact that the different archetypes can be considered as theoretical constructs that facilitate a comprehensive classification of decision-makers in a society. Egalitarians have the longest time horizon for building life. They would argue that exposure in the distant future is at least as important as exposure today, and that society should adjust its needs to limit the exposure of future generations.26 Therefore, they view buildings as long-lasting products (100 years timescale) and would rather invest in building high-quality, efficient buildings to reduce energy consumption and maintenance costs in the future. Individualists view humans as having a high adaptability through technological and economic advancement; therefore, their decision-making will be based on known damage or threats. They concentrate on the present effects rather than future losses and gains, and their time horizon for a building’s service life span is the shortest, at 20 years. They most likely will not invest in energy-efficient designs and equipment with higher upfront costs, to avoid being viewed as “risk-seeking.” Lastly, hierarchists consider nature to be in equilibrium. They view the present and future as equally important, and seek proper management to avoid future risk while searching for a balance between manageability and precautionary principles. Their time horizon for a building’s service life span typically coincides with the current life span11, 27 of 50–60 years. Different scenarios depend on the proportions of each archetype in a society. Conventional scenarios occur when each contributes an equal proportion. Here, the society envisions the global system of the future evolving without major surprises, sharp discontinuities, or fundamental transformations in the basis of human civilization. A conservative scenario occurs when the society is composed of mainly individualists and hierarchists who believe that maintaining the current balance between nature and the built environment is important, but may place more weight on satisfying individuals’ immediate needs. Potential problems may overwhelm the coping capacity of this society, but they will view it as the fate of humanity. A progressive scenario envisions exploring methods to bring about a sustainable future, where the world will undergo a new social-economical arrangement to transition to a new balance of ecological and social sustainability. Scenario analysis can assist a society in forming structured systematic thinking about the future and identifying potential problematic areas. The findings from scenario analysis can help to improve planning for future projects. Furthermore, utilizing feedback in future projects helps create a closed loop for a continuously evolving sustainable society.

Conclusion Given the complexity and intricate interactions among different impact categories, this chapter proposed a definition framework, rather than a singular definition

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of a net zero impact building. A comprehensive evaluation framework was also proposed to measure and verify the impact of building. Exposing this definition framework to a broader audience, such as policy makers, strategic planners, and design professionals, will allow new ideas and stringent regulations to be implemented in the building industry. To date, the focus has been on individual building performance and energy concentration, while other larger ecosystems and the human health impact are missing from the definition of zero energy building. This definition framework signifies the beginning of a further process to promote the net zero impact concept. The purpose is not to promote a rigid, one-size-fits-all approach to achieve ZIBs, but to set out a consistent long-term approach. The definition framework of ZIB and evaluation framework can be utilized to their full extent if properly integrated into the building design practice and supported with a transparent evaluation method.28 Chapter 8 considers three example cases to illustrate how the ZIB definition framework could be implemented to provide guidelines for a zero impact design.

References 1 Peterson, K., P. Torcellini, R. Grant, C. Taylor, S. Punjabi, and R. Diamond. A Common Definition for Zero Energy Buildings. US Department of Energy, September 2015. Accessed January 2, 2019. http://energy.gov/sites/prod/ files/2015/09/f26/A%20Common%20Definition%20for%20Zero%20 Energy%20Buildings.pdf 2 Crowther, P. “Design for disassembly to recover embodied energy.” Paper presented at 16th Annual Conference on Passive and Low Energy Architecture, Melbourne/Brisbane/Cairns, Australia, 1999. 3 Crawford, R. H, and G. J. Treloar. “Validation of the use of Australian input output data for building embodied energy simulation.” Paper presented at Eighth International IBPSA Conference, Eindhoven, Netherlands, 2003. 4 Pullen, S., D. Holloway, B. Randolph, and P. Troy. “Energy profiles of selected residential developments in Sydney with special reference to embodied energy.” Paper presented at Australian and New Zealand Architectural Science Association 40th Annual Conference, Adelaide, Australia, 2006. 5 Dixit, M. K., J. L. Fernández-Solís, S. Lavy, and C. H. Culp. “Need for an embodied energy measurement protocol for buildings: A review paper.” Renewable and Sustainable Energy Reviews 16, no. 6 (2012): 3730–3743. 6 Stephan, A., and L. Stephan. “Life cycle energy and cost analysis of embodied, operational and user-transport energy reduction measures for residential buildings.” Applied Energy 161 (2016): 445–464. 7 Morel, J. C., A. Mesbah, M. Oggero, and P. Walker. “Building houses with local materials: Means to drastically reduce the environmental impact of construction.” Building and Environment 36, no. 10 (2001): 1119–1126. 8 Attia, S., and A. De Herde. “Towards a definition for zero impact buildings.” Proceedings of Sustainable Buildings CIB. International Council for Research and Innovation, 2010.

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9 Shahrestani, M., R. Yao, Z. Luo, E. Turkbeyler, and H. Davies. “A field study of urban microclimates in London.” Renewable Energy 73 (2015): 3–9. 10 Heerwagen, Judith H. “Design, productivity and well being: What are the links?” Paper presented at AIA Conference on Highly Effective Facilities, Cincinnati, OH, 1998. 11 Ortiz, O., F. Castells, and G. Sonnemann. “Sustainability in the construction industry: A review of recent developments based on LCA.” Construction and Building Materials 23, no. 1 (2009): 28–39. 12 “ISO 14040:2006: Environmental management—Life cycle assessment— Principles and framework.” International Organization for Standardization, 2016. Accessed January 2, 2019. www.iso.org/standard/37456.html 13 Lehtinen, H., A. Saarentaus, J. Rouhiainen, M. Pitts, and A. Azapagic. A review of LCA Methods and Tools and Their Suitability for SMEs. Europe Innova Eco-Innovation Bio Chem, May 2011. Accessed January 2, 2019. www. researchgate.net/profile/Dr_Kumar79/post/How_to_measure_LCA_results_ in_a_single_index/attachment/59d622c6c49f478072e99067/AS%3A2721 19152218113%401441889669850/download/120321+BIOCHEM+LCA_ review.pdf 14 Rashid, A. F. A., and S. Yusoff. “A review of life cycle assessment method for building industry.” Renewable and Sustainable Energy Reviews 45 (2015): 244–248. 15 “Methods and modelling.” Values. Accessed January 2, 2019. www.lifecyclevalues.lu/en/research/methods-and-modelling/ 16 Khasreen, M. M., P. F. Banfill, and G. F. Menzies. “Life-cycle assessment and the environmental impact of buildings: A review.” Sustainability 1, no. 3 (2009): 674–701. 17 “U.S. Life Cycle Inventory Database.” National Renewable Energy Laboratory. Accessed January 2, 2019. www.nrel.gov/lci/ 18 Geng, S., Y. Wang, J. Zuo, Z. Zhou, H. Du, and G. Mao. “Building life cycle assessment research: A review by bibliometric analysis.” Renewable and Sustainable Energy Reviews 76 (2017): 176–184. 19 Fay, R., G. Treloar, and U. Iyer-Raniga. “Life-cycle energy analysis of buildings: A case study.” Building Research & Information 28, no. 1 (2000): 31–41. 20 “Press release: Tally™ software for LCA in building design wins national AIA award.” Kieran Timberlake, April 8, 2014. Accessed January 2, 2019. www. kierantimberlake.com/posts/view/263 21 Huang, Juan, Wei Zhang, Jiangming Mo, Shizhong Wang, Juxiu Liu, and Hao Chen. “Urbanization in China drives soil acidification of Pinus massoniana forests.” Scientific Reports 5, no. 13512 (2015). 22 Douglas, Mary, and Aaron Wildavsky. Risk and Culture: An Essay on the Selection of Technological and Environmental Dangers. University of California Press, 1983. 23 Schwartz, Shalom H. “Universals in the content and structure of values: Theoretical advances and empirical tests in 20 countries.” Advances in Experimental Social Psychology 25 (1992): 1–65.

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24 Mamadouh, Virginie. “Grid-group cultural theory: an introduction.” GeoJournal 47, no. 3 (1999): 395–409. 25 Bare, Jane C., Patrick Hofstetter, David W. Pennington, and Helias A. Udo De Haes. “Midpoints versus endpoints: The sacrifices and benefits.” International Journal of Life Cycle Assessment 5, no. 6 (2000): 319. 26 Frischknecht, Rolf, Niels Jungbluth, Hans-Jörg Althaus, Christian Bauer, Gabor Doka, Roberto Dones, Roland Hischier et al. Implementation of Life Cycle Impact Assessment Methods. Ecoinvent, Report no. 3, 2007. 27 Curran, Michael, Laura de Baan, An M. De Schryver, Rosalie van Zelm, Stefanie Hellweg, Thomas Koellner, Guido Sonnemann, and Mark A. J. Huijbregts. “Toward meaningful end points of biodiversity in life cycle assessment.” Environmental Science & Technology 45, no. 1 (2010): 70–79. 28 Attia, S., and A. De Herde. “Towards a definition for zero impact buildings.” In Proceedings of Sustainable Buildings CIB. International Council for Research and Innovation, 2010.

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Carbon-neutral development and net zero impact building Case studies

Carbon-neutral city and district Chapter 7 introduced the concept of zero impact building and outlined a framework for its definition. A zero impact building is a building that has a long service life, produces the least amount of impact from the construction process, operation of the building, and waste disposal, and creates energy by using renewable energy sources, resulting in a zero life cycle impact. The impact can be measured by energy use intensity, carbon emissions, or other units. A true net zero impact building can only exist in a carbon-neutral built environment, while a decarbonized city calls for a net zero impact design principle. In order to achieve the net zero impact objective, we must first define a carbon-neutral city.

Carbon-neutral city background and history The term “carbon-neutral city” is generally used interchangeably with other terms, such as eco-city, low-carbon city, and climate-neutral city. This book defines a carbon-neutral city as a city that acquires a net zero carbon footprint through balancing a measured amount of carbon emissions released with an equivalent amount offset. The offset can be achieved through carbon emissions reductions and/or buying enough carbon credits. In 2011, the United Nations Economic Commission for Europe produced a report outlining a range of systemic measures to make cities less energy- and carbon-intensive. Among all the primary actions necessary to realize the carbon-neutral goal, spatial planning and building design were at the heart of carbon emissions mitigation measures. A carbon-neutral city provides the foundational condition for a net zero impact building in the following aspects. First, a carbon-neutral city enables a net zero impact building by limiting urban sprawl and car density through connected public transportation and appropriate density planning. Second, the integrated green and grey infrastructure not only protect the city from adverse weather conditions, but also mitigate the negative health impacts to building occupants. The third underlying condition for a true net zero impact building is a connected and sophisticated smart energy infrastructure system, which is composed of a self-regulated energy supply grid and renewable energy generation sources. The integrated energy system can also transfer the energy generated from net zero impact building to other needed

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facilities. Accordingly, the development of net zero impact building is very much dependent on carbon-neutral city development. The carbon-neutral city has a variety of intellectual predecessors, such as garden cities,1 neotechno cities,2 and ecocities;3, 4 all these concepts had a bearing on current carbon-neutral city developments. Since the early nineteenth century, urban planning and design have been profoundly influenced by various attempts to address and mitigate the negative impacts of large-scale urbanization: environmental degradation, social inequalities, urban sprawl, and health concerns. Specifically, there were four phases that occurred in the last 200 years before the concept of carbon-neutral development came to light.

Phase one: early urban reform (1800–1890) Early urban reformers were capitalist factory owners who may have been altruistic or wanted controlled and productive workers. Manufacturing towns were designed to create better living conditions, which in turn improved worker productivity. Successful examples included New Lanark, Saltaire, and Bourneville in the UK, all of which were built in the 1800s. New Lanark is currently a United Nations Educational, Scientific and Cultural Organization (UNESCO) World Heritage Site, located southeast of Glasgow, Scotland. It was founded by David Dale and Robert Owen as a small village on the River Clyde, and later became a successful early planned town with a new factory complex and housing for workers, including a school, nursery, store, and the New Institution for the Formation of Character. It signifies a very important milestone in historical development in urban planning, where the planner attempted to blend the built environment and natural ecosystem together. Saltaire is an outstanding and well-preserved example of a mid-nineteenth-century industrial town, as well as a UNESCO World Heritage Site, located in West Yorkshire, England. It was built by Sir Titus Salt as a woolen industrial town. The town had a bathhouse, hospital, churches, pharmacies, dining hall, an institution for recreation and education, a library, concert

Figure 8.1 A bird’s-eye view of Saltaire

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hall, billiard room, science laboratory, public park, and gymnasium (see Figure 8.1). It also had schools for the children of the workers. Saltaire’s quality of living and working, along with its adequate facilities and social services, marked it as a model town, representing a landmark in enlightened nineteenth-century urban planning and design. Later, the layout of Saltaire was to exert a major influence on the development of the garden city movement.5

Phase two: garden city and followers (1890–1979) Ebenezer Howard proposed the first garden city, Letchworth, with a population of 30,000 accommodated in 1848 hectares north of London.6 It was a self-contained satellite city surrounded by a greenbelt for agriculture and other uses. Howard’s theory and idea had a huge influence on modern town planning; even critics like Jane Jacobs recognized his impact, writing: Howard’s influence in the literal or reasonably literal acceptance of his scheme was nothing compared to the influence on conceptions underlying all city planning today. City planners and designers with no interest in the Garden City as such are still thoroughly governed intellectually by its underlying principles.7 Howard wanted to tackle the twin problems of urban overcrowding and rural depopulation by constructing an entirely new form of settlement, instead of carrying out alterations or improvements to existing cities. The new form of settlement was the garden city. Its basis was initially presented through the metaphor of “the three magnets” (see Figure 8.2). The town represented the society and built environment, while the country presented the natural ecosystem. In his introduction to the book Garden Cities of Tomorrow, Howard wrote: “Neither the town magnet nor the country magnet represents the full plan and purpose of nature. Human society and the beauty of nature are meant to be enjoyed together. The two magnets must be made one.”1 In Howard’s diagram shown in Figure 8.2, the town (built environment) and country (natural ecosystem) are presented as alternate forces attracting the population. Howard’s scheme called for the creation of a third alternative, the town-country, which possesses the advantages of both and the disadvantages of neither. This third alternative has influenced the underlying principles of current eco-city and carbon-neutral city development. Besides the garden city, another tradition rooted in the twentieth century— which later drove the development of the eco-city—was the techno-city. The term was first proposed by two historians of science, Robert Kargon and Arthur Molella. They defined the planned city as developed to harness technology to construct better, more livable cities and towns known as techno-cities.8 According to their definition, techno-cities range from those in Mussolini’s Italy to the Disney creation of Celebration, Florida. This tradition mirrors the society’s understanding and demand of current technologies during that period while seeking to regain the lost virtues of the blend of man-made and natural systems. One can even argue that the techno-city may have been an early version of the current smart city. 139

Case studies Figure 8.2 Ebenezer Howard’s magnets diagram1

Phase three: grassroots movement of the eco-city (1980–2000) The major distinction between current carbon-neutral development and the early movements described above is that carbon-neutral cities are driven by the rising threat of environmental degradation, rather than the theoretical integration of the built environment and natural ecosystem. Most current carbon-neutral city developments are a direct response to further environmental pressures, such as air pollution and resource depletion, now more than ever. The term “eco-city” can be traced back to the 1980s, coined by urban theorist Richard Register in his 1987 book Ecocity Berkeley: Building Cities for Healthy Future.3 This led to the first in a series of international eco-city conferences in the 1990s.9 Throughout the 1990s, the concept was adopted by urban planners and designers, and then broadly promoted. However, there are no concrete planning principles or design strategies associated with the concept, and very few practical examples have been realized. This was mainly caused by two factors. First, the eco-city was proposed and promoted by groups of environmental activists and futurists; at that time, the concept did not translate to a set of practical guidelines and measurement methods. Second, it lacked the interest of international, national, and local governmental institutions. Without any immediate threats or benefits, the ecocity movement before 2000 was not able to generate broader attractions.

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Phase four: eco-city and carbon-neutral development (2000–present) This phase represents a blooming of the eco-city: carbon-neutral development parallel to the fast-paced net zero building development. The main driver behind the shift was unilateral governmental support and agreement and the realization that there had been a dramatic increase in carbon emissions over the course of human history. Between January 2005 and December 2017, carbon emissions rose from 378.21 ppm. to 407.56 ppm, with this trend continuing.10 Currently, the reduction of carbon emissions runs as a common thread through most initiatives, such as the Clinton Climate Initiative and the European Commission’s Eco-City projects. Similar to net zero building, carbon-neutral development began to manifest itself in the early 2000s through the concurrent globalization and mainstreaming of policy uptake and practical implementation of the ecocity.11 To date, 25 cities have pledged to become carbon-neutral by 2050, and other cities have made significant strides toward carbon emissions reductions.12 The following section will explain carbon-neutral development and the related net zero impact building design using the examples of three studies: Malmö, Sweden; HafenCity in Hamburg, Germany; and the Sino-Singapore Tianjin Ecocity in China.

Three case studies Malmö: renovation In Sweden, residential and commercial buildings account for roughly 30% of Sweden’s energy use and approximately 7% of its total carbon emissions. Sweden has set goals to reduce energy use by 20% by 2020 and 50% by 2050, compared to the 1995 baseline.11 The city of Malmö has an even more aggressive goal: to achieve carbon-neutral status by 2020. Malmö is Sweden’s third-largest city; it was formerly a prosperous industrial city (see Figure 8.3), with its identity

Figure 8.3 Map of Malmö

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strongly linked to shipyards that symbolized job security and a certain type of lifestyle. However, when the shipbuilding industry and demand for tankers disappeared almost overnight in the mid-1980s, the city’s lifeline was taken away, unemployment increased, tax revenues decreased, and the economy sank. From the mid-1990s onward, Malmö worked diligently to shift its industrial identity to become a leading knowledge hub for sustainable development. It began its transformation to a smart and sustainable city in 2001, when the city was selected as a site for the European housing exhibition Bo01 City of Tomorrow. A carbonneutral eco-district concept was developed in the context of the ambitious citywide sustainable development plans, with the city’s ultimate goal to become climate-neutral by 2020 and run entirely on renewable energy by 2030. The core of this sustainable development is the establishment of design and construction standards for materials, energy, system technology, and green space—not only for new buildings, but also in the renovation of existing buildings. In 1965, the Swedish Government passed a resolution called the Million Homes Programme to remedy the country’s housing shortage and increase the housing supply by building at least a million new homes in ten years. A large percentage of the housing in Malmö was built during that period, and many of these buildings are now close to the end of their service life and in need of renovation and energy efficiency improvements. When the project started, many houses in this area were run down and required major and immediate renovation. These old buildings did not meet current energy code requirements and presented major health problems, suffering from inappropriate ventilation, dampness, and mold. New and additional insulation was added and a new building system replaced the older ones. The renovated appearance of the buildings simulates the original designs to preserve their identity. Furthermore, energy consumption has been reduced by 10–20% compared with 2001 conditions. The renovations not only focused on energy consumption, health, and environmental impacts—social impacts were carefully considered as well. The following section will examine the City of Malmö’s carbon-neutral development from the life cycle perspectives of water, energy, and environment described in Chapter 7. Malmö is a fairly large city with varied districts requiring customized approaches and techniques. It has applied carbon-neutral (climate-neutral) concepts in several pilot districts and neighborhoods, with each district having a modified approach. Different districts are used to demonstrate each of the three life cycle perspectives.

Malmö: life cycle water assessment The Augustenborg district represents one of the largest investments in Europe in the ecological conversion of an existing residential area.13 The district used a green storm water management system which utilized green roofs and open storm water channels that lead to ponds to divert flooding while also creating a biodiverse area and beautiful landscape. The green roofs on the residential buildings are approximately 2000 m2, and a large roof garden on the commercial facility covers an additional 9000 m2. The green roof project won the United Nations World Habitat Award in 2010. The upgraded storm water management system solved the problem of constant flooding in basements and parking lots, 142

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increasing the life span of the buildings and decreasing the energy used to treat flooded areas. The results of the renovations in Augustenborg have been impressive: there have not been any floods in the area since the completion of the open storm water system. In 2007, Malmö experienced a 50-year rainfall event that cut it off from the rest of Sweden. Augustenborg was not affected at all, suggesting that the upgraded new water management system could well prepare the city for more intense rainfall in the future.14 Using the measurement framework and method proposed in Chapter 7, when measuring a building’s or built environment’s impact on the natural ecosystem, both quantity and quality must be tracked. Based on estimates, the total storm water runoff has been reduced by approximately 20% compared to conventional water management systems.14 Since 90% of storm water from roofs and other impervious surfaces is captured before being released to adjacent natural bodies of water, pollutants from the runoff from impervious surfaces—such as nutrients, solids, acids, and metals— are filtered and treated, thus improving the water quality. This is done through

Figure 8.4 Drainage channel with vegetation filter15

Figure 8.5 Open water source15

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a series of open water channels and retention ponds (see Figures 8.4 and 8.5). This district also eliminated the combined sewer overflow system to completely avoid severe contamination of the river and natural bodies of water in any future heavy rainfall events.

Malmö: life cycle energy assessment: system approach In the Western Harbour district, energy efficiency of buildings and renewable energy utilization are two key aspects of eco-district development. When the projects started, the energy performance goal was set at 105 kWh/m2/yr, which was half of what a typical Malmö housing unit used (including those buildings built in the 1960s) and below Sweden’s then standard for new construction of 110 kWh/m2/yr, which is still almost twice as high as the Passive House standard of 60 kWh/m2/yr.16 The reason the local government set such a goal was to ensure that the energy efficiency target could actually be achieved for both new construction and renovation. At the individual building level, those houses did not achieve the net zero energy target due the imbalance of energy consumption and energy generation. However, from a total district/area perspective, the Western Harbour development actually achieved the carbon-neutral development goal through the district heating and cooling system, since all energy consumed by buildings comes from locally renewable energy sources. First, a large portion of space heating and cooling (minimal requirement) is delivered by the Aktern heat pump, which has a seasonal heat storage capacity through its connection to ten cold and warm wells in an aquifer at a depth of 40–70 m. The temperature in the aquifer is constantly maintained at approximately 10–11 °C and is used for storing heat in the summer and coolness in the winter. The additional heat needed is supplied by heat from solar collectors on the building roofs (also connected back to district heating), whereas cooling is only required for commercial buildings and is supplied by wind turbines. The electricity for homes is supplied by 2 MW wind turbines and 120 m2 solar panels on the buildings. Therefore, collectively, the houses could be deemed as net zero energy buildings within the same network.

Malmö: life cycle environmental assessment Sweden has set a goal to reduce greenhouse gas emissions by 40% by 2020, to become fossil fuel-free by 2030, and to achieve the carbon-neutral goal by 2050.17 GHG emissions in Malmö have declined to 3.4 tons per year per capita, compared to Sweden’s 4.5 tons and the United States’ 16.5 tons in 2014.18 The decrease in GHG emissions represents increased energy efficiency and fewer environmental impacts since GHG emissions are a major indicator of environmental impacts and climate change. Three important aspects contribute to this reduction: economy transition, building efficiency, and renewable energy production. The city transformed from an old shipyard industrial city to a knowledge-based city focused on innovation and sustainability; the decline of heavy industry had a significant impact on reducing emissions. The use of recyclable and sustainable building materials, such as steel and wood, also contribute to the reduction of GHG emissions. Lastly, the renewable energy

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co-generation system (heat and electricity) has made it possible to curb GHG emissions even more. One important lesson that can be learned from the city of Malmö is that achieving the net zero impact goal is not an isolated effort, but instead relies on a carbon-neutral city infrastructure and network. Consequently, a systematic approach and planning are critical, and will have a longer-term and more substantial effect.

Hamburg’s HafenCity: revitalization Following EU directives, Germany has set the goal of reducing GHG emissions by 40% by 2020 and 95% by 2050 compared to the 1990 baseline. Hamburg’s goal is to reduce GHG emissions by 30% by 2020 and 80% by 2050 to contribute to the national goal.19 The development of HafenCity is based on a master plan approved by the Hamburg Senate on February 29, 2000.20 The site was formerly an old port with some ship sheds, but since 2000 it has become one of most interesting sustainable urban redevelopments in Europe. Hamburg is the second-largest city in Germany, with over 5 million people living in the metropolitan region. It is also a historical industrial city with Europe’s third-largest port. Unlike Malmö, Hamburg has a growing economy with a fairly diverse workforce. It successfully transitioned from a predominantly industrial town to a city with a diverse economic structure; currently, the service sector is its biggest economic sector. In 2015, Hamburg exceeded the gross national product per capita, reaching an average of €90,095.21 The entire HafenCity development is scheduled to be completed in 2025, and by that time the built area of Hamburg’s city center will be enlarged by about 40%, consequently providing 40,000 jobs and 5500 new homes. The development will include a wide mix of uses—such as housing, recreation, retail, services, offices, and cultural destinations—and will connect conveniently to the Hamburg city center through the subway and buses (see Figure 8.6). HafenCity has considerably high standards regarding its energy consumption reduction goal. Health and environmental protection measures—the Figure 8.6 Map of HafenCity

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most significant contribution of this eco-district—have also been written into the overall development plan with detailed requirements. Instead of expanding Hamburg’s existing municipal area to the outskirts, HafenCity revitalized the old city port, which encompasses 157 hectares of a former industrial and contaminated site. The city even developed its own green building certification system (Ecolabel) to reward developers for sustainable design, management of energy, public goods, construction materials, and for providing a healthy and comfortable environment for residents. The Ecolabel was introduced in 2007 based on the concept that (1) all new buildings initially have a negative impact on the natural ecosystem by occupying land and consuming materials and energy during construction, but (2) they can also positively complement the natural environmental by improving the micro-climate and providing a sense of stability and community. Initially, participation in the HafenCity Ecolabel was voluntary for house builders, but since 2012 compliance with the rigorous ecological label is a requirement.22 The Ecolabel uses multiple criteria to assess the sustainability of projects with quantitative and qualitative approaches by using different environmental indicators. The following section will investigate the Ecolabel standard from the life cycle perspectives of energy, environment, health, and water.

Hamburg’s HafenCity: life cycle energy assessment In order to receive the Ecolabel gold certificate, there are five categories of requirements that must be met. The first category is energy: the total primary energy consumption of the building must decrease by 30%, compared to the German Energy Saving Ordinance EnEV 2009, and the heat transfer coefficient must drop by 40% for opaque areas and 30% for the rest of the building. Not only do applicants need to submit documents illustrating the design intents and simulation results, but the first two years of actual building energy use must be recorded and then converted to primary energy and checked against the design intent. If a minimum of 70% of the area functions as planned, then the certification can be verified and achieved.23

Hamburg’s HafenCity: life cycle environmental assessment The second category addressed by the Ecolabel is the “sustainable management of public goods,” which addresses social responsibility beyond immediate benefits and control over built projects, and has a particular focus on environmental and societal benefits. Preventing pollution of the River Elbe and providing public access to ground floors are among the design strategies implemented to ensure the renovation effort will protect public goods. Furthermore, the convenient public transportation system promotes the idea of a car-free lifestyle. Other qualities associated with public goods are the waste management system, bike parking space, and walkable retail spaces, among others. How HafenCity achieved its low-car dependency goal is significant. Based on Hamburg’s general guidelines, 0.8 car parking spaces must be provided for each apartment unit. In order to realize the sustainable mobility concept, the target of HafenCity is to provide parking for a maximum of 25% of the figures stipulated in the general guidelines,

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amounting to no more than 0.2 parking spaces per apartment unit (five apartment units share one parking spot). To ensure this target can be achieved, all building residents must declare in a contractual agreement that they will refrain from owning a car.24 Actions for protecting public goods require buy-in from the public, support from legislation, and enforcement by the local jurisdiction. For instance, as mentioned in Chapter 4, one of the missing considerations in the current net zero practice is the transportation energy consumed by building residents. In order to reduce unnecessary energy spent on private transportation, higher-level regulations are needed to encourage the use of public transportation. To this extent, HafenCity has established an effective model. The third category is the “use of eco-friendly construction materials.” As explained in previous chapters, a building’s operation as well as the activities to construct it have considerable impacts on the environment. Beginning from the period when raw materials are extracted from the ground to produce building components, the building has already started to negatively impact the environment. By using eco-friendly materials, HafenCity reduced potential environmental impacts and long-term health risks caused by harmful building materials, such as paints with high volatile organic compound (VOC) levels. Selecting eco-friendly materials means the design team searches for materials and products that have been manufactured with minimum processing input while achieving the same functionality and durability as non-eco-friendly materials. The third category also restricts the use of construction materials that could be harmful to human health. For instance, some foam plastics with halogenated foaming agents (e.g., HCFC and HFC) or flooring materials containing polyvinyl chloride (PVC) are harmful and are forbidden by Ecolabel requirements.24 The fourth category devotes special consideration to “health and wellbeing.” Users’ health is impacted by the indoor environment, thermal comfort level, acoustic quality, lighting level, and other important characteristics of buildings. Careful selection of building systems and improvement of structural elements can prevent other risks and hazards, such as fire, noise, and mold.

Hamburg’s HafenCity: life cycle water assessment The fifth category relates to “sustainable building operations.” During their operation, buildings continue to consume energy and water while emitting pollutants, such as exhaust and black water. The Ecolabel requires the installation of watersaving sanitary ware, such as monobloc mixer taps with flow regulators, low-flush volume toilets (6 liters), dual-flush water closets, and water-saving showers with the goal to reduce potable water consumption by at least 30%.24 Furthermore, category three prohibits the use of heavy metals, such as copper and zinc, as building façade material, to avoid water contamination.

Sino-Singapore Tianjin Eco-city: life cycle water assessment The Sino-Singapore Tianjin Eco-city is a joint government project between China and Singapore. The agreement between the two countries was signed in 2007 to respond to rapid urbanization, increasing pollution, and additional long-term

147

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environmental damage. The concept of a low-carbon eco-city combines lowcarbon development and eco-city concepts, and has been an emerging model in China since 2008.25 The concept was initiated by the Chinese Society for Urban Studies (CSUS). In a 2009 report, CSUS released the Chinese Low Carbon Eco-city Development Strategy, outlining policies and techniques to advance lowcarbon urban development and design strategies.26 In the 13th Five-Year Plan (2016–2020) released by the central government, China announced its goal to reduce energy use and carbon intensity by 15% and 18% respectively, compared to 2015 levels,26 eventually leading to the ultimate goal of reducing overall carbon intensity by 40–45% in 2020 compared to 2005 levels.26 These are crucial development strategies and drivers behind low-carbon eco-city developments such as Tianjin Eco-city. Tianjin Eco-city covers an area of 30 km2 with a population of 350,000 (Figure 8.7). It is situated 15 km from Tianjin Binhai New Area, 45 km from Tianjin, and 150 km from Beijing. The site was chosen for several reasons. From an environmental perspective, this vulnerable wasteland was selected to avoid using precious farmland and reclaiming previously contaminated land.27 From an economic and social perspective, the Beijing–Tianjin–Bohai Bay area is one of the fastest-developing clusters in China, with an average growth rate of 12.4% between 2011 and 2015.28 This project is meant to provide a brand-new model for sustainable urbanization in response to the profound environmental and health impact concerns caused by rapid urbanization in China. By 2014, the start-up area of 3 km2 was finalized, and around 10,000 residents moved into the city.29 The entire eco-city has three centers, four districts, and one axis (see Figure 8.8). To plan, design, build, and monitor the development targets, an eco-design planning system was created for this particular project. The system comprises 22 quantitative key performance indicators (KPIs) and four qualitative KPIs.30 These cover life cycle energy assessment

Figure 8.7 Map of Tianjin Eco-city

148

Case studies Figure 8.8 Eco-cells and Eco-district31

(including renewable energy), life cycle water assessment (water use, solid waste, and water environment), life cycle environmental assessment (air quality, landscape, acoustic environment (noise), and transportation. The master plan has an overall target to reduce 70% of energy consumption, compared to the conventional built environment, and to integrate at least 20% of renewable energy.31 The KPIs also require 100% green buildings and 90% green transportation by 2020. For green transportation, several design strategies have been implemented to create a walkable community and pedestrian-friendly built environment. Starting with the planning stage, the mixed-used districts were divided into Eco-cells of 160,000 m2 with 2500 dwelling units, each cell hosting about 8000 residents. Four Eco-cells form an Eco-neighborhood,32 which shares a neighborhood center, market, kindergarten, primary school, and other public amenities. Such planning makes it possible for residents’ daily activities to be carried out within walking or biking distance, thus reducing the traffic load and demand. Several Eco-neighborhoods form an Eco-district, which consists of a commercial center, business park, civic service, and public transportation nodes. Most residents’ daily commutes can be accomplished within a 2 km radius.

149

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Secondly, all roads in the Eco-city have a 5 m-wide designated non-motorized lane for pedestrians and cyclists.34 In addition to a pedestrian zone, a light rail transit system connects the Eco-city to other districts, and trams and electric buses are available as alternative green transportation methods. For green buildings, this project took a similar approach to the cities of Malmö and HafenCity and created its own green standard. The Eco-city administrative committee and the Building and Construction Authority (BCA) of Singapore jointly developed the Green Building Evaluation Standards (GBES) to evaluate all buildings constructed for this project. The GBES were based on the BCA’s Green Mark System and Green Start System, which were adopted by the Chinese Ministry of Housing and Urban-Rural Development. In order to demonstrate and promote the GBES, an eco-city investment and development company built a low-carbon living lab (LCLL) to showcase design strategies and technologies that could be applied. There are ten eco-technology features implemented in the LCLL (see Figure 8.9). First, the design team allows the natural environment to shape the building; the building has compact massing with a particular orientation to create the ideal external micro-climate and to optimize sun exposure while reducing heat loss. The LCLL has a large atrium to reduce lighting energy consumption by maximizing daylight. Compared to a building without an atrium, the LCLL has reduced energy use by 3.2%.33 Other design strategies and techniques used in the LCLL include a double-skin vertical green façade, lighting shelves, and an exhaust heat recovery system. As outcomes, this particular building consumed 30% less energy compared to similar buildings in Tianjin, which is the equivalent of 171 tons of coal and 427 tons of carbon emissions.35 Furthermore, 30% of the lab consisted of recycled materials, which is three times higher than the requirements of the GBES. Figure 8.9 Low-carbon living lab34

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Case studies

Regarding water, 50% of the water was derived from non-traditional water resources, such as grey water reuse; additionally, 80% of rainwater was collected onsite without being discharged into public sewers.34 The renewable energy system generated 60% of the annual heating/cooling and hot water demand of the building, and also covered 12% of the annual electricity demand. The renewable energy technologies used include solar thermal energy to produce hot water, solar PV panels, a wind turbine, and a ground source heat pump.

Conclusion Table 8.1 provides a summary and comparison of the three carbon-neutral cities and their net impact building practices. In developed countries, carbon-neutral cities have been developed primarily to provide revitalization opportunities for previous heavy-industry towns. Carbon-neutral developments serve as an economic engine to transition older local industrial economies to newer, upcoming knowledge-based economies. Net zero impact building designs and construction are used as learning opportunities as well as to showcase innovative technologies that reduce impacts on the environment and human health. In developing countries, carbon-neutral cities have been developed primarily to find a better solution to reduce the environmental impact while maintaining developing needs, and secondarily to benefit from central government’s financial incentives.34 What is common among the net zero building designs and construction in the three cities is the holistic life cycle approach. Energy— in particular, operating energy—is no longer the focal point. The impacts on water, environment, and health have been integrated in the overall development goals, leading to new building design guidelines. Embodied and transport energy have also been included and have become the leading principles of master plan development. What is interesting is that none of the three cities rely on super-advanced technologies. The green building designs and requirements created particularly for these three cities demonstrate three key points. First, using existing building technologies and materials is sufficient to achieve the net zero impact target. Second, despite each city having its own unique development objectives, they share many common net zero practice principles. The particular carbon emissions reduction or energy consumption reduction targets may differ; however, the holistic design process and approaches are quite similar. Third, a progressive society is necessary to make big changes in how we design and build buildings and cities, and this progressive scenario embodies public buy-in, legislation support, and local jurisdiction enforcement of net zero impact development. Overall, current carbon-neutral development appears to reflect an urgent response to ongoing climate change discourses. Driven by the dual necessity to decarbonize cities and revitalize traditional economic structures, eco-cities have been become a promising solution to balance social and environmental demands. Eco-cities promise an opportunity to stimulate urban development and regeneration through social-technological innovation,20 with net impact building design located in the center of this movement. 151

300,000

79.82 km2

Carbon-neutral by 2030

Green trips 100%

All municipal operations run on 100% renewable energy by 2030

Innovative storm water management system

Reduce waste, increase employment rate, and increase biodiversity to improve outdoor and indoor living environment

n/a

Population

Area

Life cycle environment: carbon-neutral goal

Life cycle environment: transportation

Life cycle energy

Life cycle water

Life cycle health

Net zero/net impact building standard

Malmö

Table 8.1  Comparison of three case studies21, 29, 35

Ecolabel

Indoor air quality, thermal comfort (DIN EN 15251) Avoid VOC content Avoid biocides or fungicides Avoid heavy metals

Flood control, potable water use reduction (>30%)

Reduce site consumption by 30% by 2030 and primary consumption by 80% by 2050, compared to 2008 levels

Increase the share of bike traffic by 25% by 2020

Reduce carbon emissions by 40% by 2020 and 80% by 2050, compared to 1990 levels

2.39 km2

3275

HafenCity

Green Building Evaluation Standards

—

At least 50% of the city’s water should be sourced by desalination and recycling by 2020

Renewable energy usage > 20%

Green trips > 90%

Carbon emissions per unit GDP: ≤ 150 tons per US$1 million GDP

30 km2

350,000

Tianjin Eco-city

Case studies

References 1 Howard, Sir Ebenezer. Garden Cities of Tomorrow: Being the Second Edition of Tomorrow; a Peaceful Path to Real Reform. S. Sonnenschein & Co., 1902. 2 Geddes, Patrick. City in Evolution. Williams and Norgate, 1915. 3 Register, Richard. Ecocity Berkeley: Building Cities for a Healthy Future. North Atlantic Books, 1987. 4 Roseland, Mark. “Dimensions of the eco-city.” Cities 14, no. 4 (1997): 197–202. 5 Saltaire. UNESCO. Accessed January 2, 2019. www.mikeclarke.myzen. co.uk/Saltaire.pdf 6 Miller, Mervyn. Letchworth: The First Garden City, Vol. 2. Phillimore, 2002. 7 Jacobs, Jane. The Death and Life of American Cities. Random House, 1961. 8 Kargon, Robert H., and Arthur P. Molella. Invented Edens: Techno-cities of the Twentieth Century. MIT Press, 2008. 9 Joss, Simon. “Eco-cities: The mainstreaming of urban sustainability—key characteristics and driving factors.” International Journal of Sustainable Development and Planning 6, no. 3 (2011): 268–285. 10 “Carbon dioxide—direct measurements: 2005–present.” NASA Global Climate Change. Accessed January 2, 2019. https://climate.nasa.gov/vitalsigns/carbon-dioxide/ 11 Medineckiene, Milena, E. K. Zavadskas, Folke Björk, and Z. Turskis. “Multi-criteria decision-making system for sustainable building assessment/certification.” Archives of Civil and Mechanical Engineering 15, no. 1 (2015): 11–18. 12 “25 cities commit to become emissions neutral by 2050 to deliver on their share of the Paris Agreement.” C40 Cities, November 12, 2017. Accessed January 2, 2019. www.c40.org/press_releases/25-cities-emissions-neutralby-2050 13 “7 Examples of sustainability in Sweden.” Sweden/Sverige. Accessed January 2, 2019. https://sweden.se/nature/7-examples-of-sustainability-in-sweden/ 14 “Urban storm water management in Augustenborg, Malmö (2014).” European Climate Adaption Platform. Accessed January 2, 2019. https:// climate-adapt.eea.europa.eu/metadata/case-studies/urban-storm-watermanagement-in-augustenborg-malmo/#objectives_anchor 15 “Urban storm water management in Augustenborg, Malmö (2014): Solutions.” European Climate Adaption Platform. Accessed January 2, 2019. https://climate-adapt.eea.europa.eu/metadata/case-studies/urban-stormwater-management-in-augustenborg-malmo/#solutions_anchor 16 Austin, Gary. “Case study and sustainability assessment of Bo01, Malmö, Sweden.” Journal of Green Building 8, no. 3 (2013): 34–50. 17 Giest, Sarah. “Big data analytics for mitigating carbon emissions in smart cities: opportunities and challenges.” European Planning Studies 25, no. 6 (2017): 941–957. 18 “CO2 emissions (metric tons per capita).” The World Bank. Accessed July 20. 2017. https://data.worldbank.org/indicator/EN.ATM.CO2E.PC?view=map 19 The Hamburg Climate Action Plan. City of Hamburg, 2011. Accessed January 2, 2019. www.hamburg.de/contentblob/4028914/6bdf8a2548ec96c97aa0b 0976b05c5d9/data/booklet-englisch).pdf

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20 “The HafenCity project.” HafenCity Hamburg. Accessed January 2, 2019. www.hafencity.com/en/overview/the-hafencity-project.html 21 “Hamburg in profile.” HK Chamber of Commerce. Accessed January 2, 2019. www.hk24.de/en/produktmarken/economic/hamburg-profil/1159510 22 Carvalho, Luís, Giuliano Mingardo, and Jeroen Van Haaren. “Green urban transport policies and cleantech innovations: Evidence from Curitiba, Göteborg and Hamburg.” European Planning Studies 20, no. 3 (2012): 375–396. 23 Sustainable Construction in HafenCity. HafenCity Hamburg. Accessed January 2, 2019. www.hafencity.com/upload/files/files/Sustainable_ Construction_1.4.pdf 24 Hamburg—European Green Capital: 5 Years On. Freie und Hansestadt Hamburg, June 2016. Accessed January 2, 2019. http://ec.europa.eu/ environment/europeangreencapital/wp-content/uploads/2011/04/HamburgEGC-5-Years-On_web.pdf 25 Zhou, Nan, Gang He, and Christopher Williams. China’s Development of Low-carbon Eco-cities and Associated Indicator Systems. No. LBNL--5873E. Lawrence Berkeley National Lab, 2012. 26 Tianjie, Ma. “China’s ambitious new clean energy targets.” The Diplomat, January 14, 2017. Accessed January 2, 2019. https://thediplomat. com/2017/01/chinas-ambitious-new-clean-energy-targets/ 27 “Planning structure.” Sino-Singapore Tianjin Eco-city. Accessed January 2, 2019. www.tianjineco-city.com/en/SinglePage.aspx?column_id=10311 28 “Tianjin economy continues to grow.” China Daily, June 13, 2016. 29 Tianjin, Eco-City, China. Urban NEXUS, August 2014. Accessed January 2, 2019. www2.giz.de/wbf/4tDx9kw63gma/05_UrbanNEXUS_CaseStudy_ Tianjin.pdf 30 “KPIs.” Sino-Singapore Tianjin Eco-city. Accessed January 2, 2019. www. tianjinecocity.gov.sg/bg_kpis.htm 31 Yao, Peng Cheng, and Lim Chin Chong. “Planning strategies for leading energy efficient and sustainable city development: Case study of Sino-Singapore Tianjin Eco-city.” Paper presented at Second China Energy Scientist Forum, 2010. Accessed january 2, 2019. http://file.scirp.org/pdf/19-1.30.pdf 32 “Environmental protection.” Sino-Singapore Tianjin Eco-City. Accessed January 2, 2019. www.tianjinecocity.gov.sg/col_environmental.htm 33 “Successful projects.” Sino-Singapore Tianjin Eco-city. Accessed November 10, 2017. www.tianjineco-city.com/en/SinglePage.aspx?column_id=10430 34 Geroe, S. J. W. “The Sino-Singapore Tianjin Eco-city: A case study of Chinese experimental regulatory and institutional development.” International Journal of Sustainable Development and Planning 12, no. 6 (2017): 987–994. 35 “Sustainable Malmö.” Malmö stad. Accessed January 2, 2019. https:// malmo.se/Nice-to-know-about-Malmo/Sustainable-Malmo-.html

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1800–1890: early urban reforms 138–139 1890–1979: garden cities 139 1930–1969: early solar house 2–3, 18, 101 1970–1989: first energy crisis/emergence of net zero energy building 3–4 1980–2000: grassroots movement 140 1990–2006: second energy crisis/consensus on net zero energy building 7–9 2000–present: carbon-neutral development 141–152 2007–2010: financial crisis/rapid development 9–10 2011–2017: financial recovery/blooming of net zero energy building 10–12 2018–beyond 12–13 ability measures 122, 124, 131 ACEEE see American Council for an Energy-Efficient Economy acidification, water 122–123, 129–130 active design 21–23, 25–27 active phase-change materials 105–108 adaptive reuse phases 63, 65 advanced materials and systems 12–13, 60–61, 86–87, 96–116 aerogel 97–98 AIA see American Institute of Architects air conditioning 4, 31, 36, 78, 82, 87, 100, 103 air quality 44–47, 53, 75, 86–87, 107–108, 124, 131, 149, 152 American Council for an Energy-Efficient Economy (ACEEE) 4, 17 American Institute of Architects (AIA) 13, 21, 36, 62 American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) 31, 36, 78, 82 annual embodied energy 63 Arab World Institute 113–114

archetypes of people 132–133 artificial neural networks (ANN) 32–33 ASHRAE see American Society of Heating, Refrigerating and Air-Conditioning Engineers Asia: asset value-market demand 46–47; drivers and economics 78–82, 85; Hong Kong Zero Emission Center 23, 28–30, 44; Sino-Singapore Tianjin Eco-city 147–152; social-community impacts 51; urbanisation/urbanism 11–12, 42, 65–66 assessments and metrics 17–40 assets, value–market demand 46–48 Australia 80, 82 BDCES see Building Design Criteria for Energy Saving Berman, Sam 4 biodiversity 124, 142, 152 bioluminescent 113 biometric integration 75, 87–88, 90 bottom line concepts 131–132 Bourneville, United Kingdom 138 Brabantwoningen (Brabant House), The Netherlands 23, 26–28, 44 BREEAM (Building Research Establishment Environmental Assessment Method) 5, 46 building codes/standards 10–12, 75–85 Building Design Criteria for Energy Saving (BDCES) 79–80 building regulations 10–12, 37, 66, 69, 76–84, 117, 126–127, 147 Building Research Establishment Environmental Assessment Method (BREEAM) 5, 46 Bush, Vannevar 2–3 Cabot, Godfrey L. 3 California Institute for Energy Efficiency (CIEE) 6

155

Index

Californian building codes/standards 10–12, 78 Canada 45, 77–78, 82 carbon emissions see greenhouse gases carbon-neutral development: cities/districts 68–69, 137–154 Carson, Rachel 52 Carter, Jimmy 4 CCREUB see Criteria for Clients on the Rationalization of Energy Use for Buildings CCREUH see Criteria for Clients on the Rationalization of Energy Use for Houses chemical heat-of-fusion 3, 100–101 chemoluminescense 113 Chile 84 China: Hong Kong Zero Emission Center 23, 28–30, 44; regulatory drivers 80–81; Sino-Singapore Tianjin Eco-city 147–152; social-community impacts 51; urbanisation/urbanism 11–12, 42, 65–66 CIEE see California Institute for Energy Efficiency codes, building codes/standards 10–12, 75–85 color changing responsive materials 109–110 community impacts 51–54 consensus on net zero energy building 7–9 consequences of net zero building 58–74 construction: advanced materials and systems 12–13, 60–61, 86–87, 96–116; future drivers and economics 76–81, 85–92; historical perspectives 5–13; human health 75, 86–87; impact of net zero building 42, 48–51, 54, 117–123, 127–133, 137–152; metrics and assessments 26–27, 37–38; unintended consequences 58–66, 69–70 convergent networks 88 cooling 21–26, 30–32, 43–44, 67, 100–110, 117, 144 costs: advanced materials 99–101; consequences of net zero building 61–62, 65–70; economic drivers 91–92; elite pursuits 65–66; historical perspectives 5–7; impacts of net zero building 44–45, 50–51, 119, 122, 133; net zero energy cost building 5–7, 17–19, 23, 26–28, 30, 34, 36–37; renewable energy 61–62, 69–70 Criteria for Clients on the Rationalization of Energy Use for Buildings (CCREUB) 78–79 Criteria for Clients on the Rationalization of Energy Use for Houses (CCREUH) 79

156

cultural-social shifts 52–54 cultural theory 132–133 current phase-change material applications 101–108 Davis Langdon publications 92 daylighting 12, 21–25, 30, 47, 114, 150 DCGREUH see Design and Construction Guidelines on the Rationalization of Energy Use for Houses demolition energy 63, 118 Denmark 5, 45, 83 Design and Construction Guidelines on the Rationalization of Energy Use for Houses (DCGREUH) 78–79 deviation aspects 61–62 direct benefits 42–48 direct embodied energy 118 divergence aspects 61–62 Douglas, Mary 132 drivers of net zero building 75–95 early urban reforms (1800–1890) 138–139 Eco-cells 149 “ecocentrism” 53 eco-cities/districts 68–69, 137–152 Ecolabel certificate 146–147, 152 ecological degradation 69–70 ecological economics 1–4, 9–13, 58–70 ecological origins 1–2, 5, 13, 58–70 economics: drivers of 75–77, 83, 87, 91–92; ecological economics 1–4, 9–13, 58–70; renewable energy 61–62, 69–70; zero impact building 119, 126–127, 131–134, see also costs Edge building, Amsterdam 88–89 Efficienhauz Plus houses 18, 20 Efficient Use of Energy 4 egalitarians 132–133 electrochromic materials/windows 12, 110–111 electroluminescense 113 elite pursuits 65–66 embodied energy 25, 37, 62–70, 117–129 emergence of net zero energy building 3–4 emergy 2 emissions see greenhouse gases; net zero energy emissions energy balance 1–2, 13, 19–20, 30–38, 62–63, 68–70 “energy bank” project 4 energy conservation 4–11, 38, 42–49, 52–53, 78–79, 81–82, 85–87 energy consumption/assessments: building codes/standards 77–85; environmental

Index

drivers 76, 86–87; historical perspectives 3–13; impacts of net zero building 42–48, 51–53, 118–134; life cycles 58–70, 118–120, 143–152; metrics and assessments 17, 20–38 energy costs 76, 100, 122; net zero energy cost building 5–7, 17–19, 23, 26–28, 30, 34, 36–37; renewable energy 61–62, 69–70 energy crisis 3–4, 7–9 “Energy, ecology, and economics” 2 energy emissions, net zero emissions 7, 17–20, 23–24, 28–30 energy flow, principles of 1–2, 58–61 Energy Star label 45 Energy Survey of North America 1 enforcement aspects 13, 77, 80, 147, 151 entropy 1–2, 99–100 envelope aspects 4, 8, 26, 31–32, 67, 78, 100 Environmental Accounting: Emergy and Environmental Decision Making 2 environmental drivers 75–76, 82, 85–92 environmental impacts 121–133; ecological degradation 69–70; embodied energy 25, 37, 62–70, 117–118, 123–129; life cycle assessments 126–133, 142–152 Environment, Power and Society 2 EU see European Union Europe 7–8; asset value–market demand 46, 48; energy and resource conservation 43; evolution of net zero energy 7–8, 10–11; labor force building benefits 49–51; social-community impacts 51, see also individual countries European Union (EU) 9–11, 65, 77, 83–85, 92, 145 eutectic phase-change materials 100–101 eutrophication, water 122–123, 129–130 evaluation frameworks 117–134 evolution aspects 1–16 existing energy calculation methods 30–33 façades 103, 107–108, 114 fatalists 132–133 Feist, Wolfgang 5, 7 Feynman, Richard P. 97 financial crisis 9–10 financial recovery 10–12 first energy crisis 3–4 France 19, 76, 83 “free” label/viewpoints, renewable energy 61–62, 69–70 Fukushima disaster, Japan 11, 79 future directions: 2018–beyond 12–13; drivers and economics 75–95

garden cities 139–140 Georgescu-Roegen, Nicholas 1–2 Germany: energy and resource conservation 43–44; evolution of net zero energy 5–8; HafenCity–revitalization 145–147, 150, 152; labor force building benefits 49–51; metrics and assessments 20, 35, 37; Passivhaus standard 5, 18, 43–44; regulatory drivers 83 GHG see greenhouse gases glass insulating units (GIU) 103–105 GLASSX 103–104 global warming 75–76, 123–125, 129–130 grassroots movement, eco-cities 140 Great Recession 9 green buildings: advanced materials and systems 96–116; case studies 137–152; drivers of 78–81, 86–92; embodied energy 63–70; evolution of 9, 12; labor force building benefits 48–51; predicted impacts of net zero building 42–54; productivity benefits 44–47; sustainability and self-organization 59–60 greenhouse gases (GHG) 7, 11–12, 67; future drivers and economics 76, 80; metrics and assessments 19–20, 33–35, 37–38; zero impact building 117, 121, 144 green lifestyles 66–69 green urbanism 68–69 Gulf War 7 HafenCity–revitalization, Hamburg 145–147, 150, 152 health: advanced materials and systems 86–87; construction 75, 86–87; drivers of 75–76, 85–88, 92; life cycle assessments 126–127, 131–134, 142–152; materials 75, 86–87; productivity benefits 44–47, 119, 131–133; sick building syndrome 45, 85, 126; urbanisation impacts 122–126, 131–134; well-being benefits 42–47, 75, 85–87, 122, 147; zero impact building 122–126, 131–134 heat/heating: advanced materials and systems 99–112; evolution aspects 2–4, 8, 12; future drivers and economics 78, 86–87; life cycle assessments 117, 121–125, 130, 144–146, 150–151; metrics and assessments 24–26, 30–32, 36; phase change materials 100–107; predicted impacts 43–44, 52; unintended consequences 67, 70 heating, ventilation, and air conditioning (HVAC) systems 4, 31–33, 78, 102 heat island effect 121, 124–125

157

Index

heat-of-fusion 3, 100–101 hermits 132–133 hierarchical organization 58–59, 67 hierarchists 132–133 high-cost/high-tech elite pursuits 65–66 historical perspectives 1–12, 17–18, 137–141 Hong Kong Zero Emission Center, China 23, 28–30, 44 Howard, Ebenezer 139–140 HVAC see Heating, ventilation, and air conditioning IECC see International Energy Conservation Code IGCC see International Green Construction Code impact indicators: carbon-neutral development 137–154; life cycle assessments 117–136; predictions of net zero building 41–57 incentives, regulatory drivers 75–77 India 46–47, 81, 85 indirect benefits 42–43, 45, 48–54 indirect demolition energy 118 indirect embodied energy 118 individualists 132–133 indoor air quality 75, 86 induced energy 36, 119–120, 125 initial embodied energy 118 inorganic phase-change materials 100–101 insulation 142; advanced materials and systems 97–103, 107; evolution aspects 4–8, 12; future drivers and economics 79, 86–87; metrics and assessments 22–26, 33; nanotechnology 97–98, 100; predicted impacts 53 integrated frameworks, eco-districts/green urbanism 68–69 International Energy Conservation Code (IECC) 78 International Green Construction Code (IGCC) 78 Italy 83, 139 Japan 11, 20, 78–81 key performance indicators (KPI) 148–149 Kistler, Walter P. 112 Korea 20, 34–36, 68–69, 78–81, 85 Korsgaard, Vagn 5 KPI see key performance indicators labor force building 48–51 land use impacts 121

158

latent heat 100–102 laws of thermodynamics 1, 13, 58, 100 LCA see life cycle assessments LCLL see low-carbon living lab Leadership in Energy and Environmental Design (LEED) 9, 45–46, 54, 62, 91, 122 LED see light-emitting diodes Letchworth, United Kingdom 139–140 life cycle assessments (LCA) 117–136, 142–152; energy assessments 58–70, 118–120, 143–152; environmental impacts 126–133, 142–152; health 126–127, 131–134, 142–152; renewable energy 61–70; social aspects 126–127, 131–134, 142–152; water 126–130, 142–144, 147–152; zero impact building 117–136 life cycles 58–74; embodied energy 62–70, 118; energy consumption 58–70, 118–120, 143–152 life-style aspects 66–70 light-emitting diodes (LED)/materials 112–113 lighting 138, 147, 150; advanced materials and systems 103–104, 109–114; daylighting 12, 21–25, 30, 47, 114, 150; evolution aspects 4–5, 12; future drivers and economics 78, 88–90; life cycle assessments 117, 122–124, 131; metrics and assessments 21–25, 30; predicted impacts 44–47, 70 low-carbon living lab (LCLL) 150–151 low-density developments 66–69 maintenance, technology drivers 75, 87–88, 92 Malmö–renovation, Sweden 141–145, 150, 152 mandates 76–85 materials: advanced systems 12–13, 60–61, 86–87, 96–116; human health 75, 86–87 metrics and assessments 17–40 MHUR see Ministry of Housing and Urban-Rural Development Minergie standard 8, 18–19 Ministry of Housing and Urban-Rural Development (MHUR), China 11–12 MIT solar house projects 2, 101 Molecular/Nano Engineering Building, University of Washington 103 motivation measures 122, 124, 131 nanotechnology 96–103 National Energy Code of Canada for Buildings (NECB) 78

Index

National Institute of Standards and Technology (NIST) 9 National Renewable Energy Laboratory 4, 7, 17, 128 natural ventilation 21, 23, 25, 107 nearly zero energy building 10–12, 19–20, 77, 90 NECB see National Energy Code of Canada for Buildings net energy concept origins 1–2, 5, 13, 58–70 The Netherlands 3, 23, 26–28, 44 net zero building, definitions 17–20, 117, 125–126 net zero energy cost building 5–7, 17–19, 23, 26–28, 30, 34, 36–37 net zero energy emissions 7, 17–20, 23–24, 28–30 net zero site energy building 6–7, 17–23, 25, 30, 33–34, 36–37 net zero source energy 7, 17–20, 23–25, 30, 33–36 New Lanark, United Kingdom 138 New Zealand, regulatory drivers 82 NIST see National Institute of Standards and Technology North America 7, 41, 82, 104–105, 128, see also United States Norway 20, 23–25, 44, 64, 77 Nouvel, Jean 114 obsolescence types 63, 65 occupant’s transport energy 118–119 Oceania, regulatory drivers 80, 82 Odum, Howard 2, 58–59 OPEC see Organization of the Petroleum Exporting Countries operating energy 58, 69, 117, 123, 128–129, 151 opportunity measures 122, 124, 131 organic phase-change materials 100–102 Organization of the Petroleum Exporting Countries (OPEC) 3–6 origins, net energy concept 1–2, 5, 13, 58–70 “overdiscounting the future” aspects 53 ozone depletion 75, 123, 125, 129–130 passive design 21–23, 26–30 Passive House Pioneer Award 5 Passive House standards 5–8, 18, 43–44, 77, 144 passive phase-change materials 103–105 Passivhaus standard 5, 18, 43–44 PAVEGE flooring systems 112–113

PCM see phase-change materials phase-change materials (PCM) 99–108 photochromic materials/paints 109–110 photoluminescense 113 photovoltaic systems 9, 23, 25–27, 66–67, 112 piezoelectric materials/tiles 109, 112–113 policy, regulatory drivers 75–82 positive energy buildings 18–19, 37, 46, 90 “positive illusion” 53–54 Powerhouse Kjørbo, Sandvika, Norway 23–25, 44 predicted impacts of net zero building 41–57 predictive maintenance 75, 87–90, 92 primary energy see source energy principles of energy flow 1–2, 58–61 principles of zero energy building 17–40 productivity benefits 44–47, 119, 131–133 qualitative/quantitative impacts 121, 129 radiant time series method (RTSM) 32 rapid development aspects 9–10 Register, Richard 140 regression methods 32 regulations, building regulations 10–12, 37, 66, 69, 76–84, 117, 126–127, 147 regulatory drivers 75–85, 92 Reinventing Green Building 54 renewable energy: advanced materials 100; costs and economics 61–62, 69–70; embodied energy 63; “free” label/viewpoints 61–62, 69–70; future drivers and economics 78–80; historical perspectives 4–5, 7, 10; impacts of net zero building 44, 49–52, 117–119, 123, 128–130, 137–138, 144–145, 149–152; life cycle assessments 61–70; metrics and assessments 17, 19–20, 23, 28, 30, 34–36; unintended consequences 61–63, 66, 68–70, see also solar energy resource conservation 42–44, 49, 52–53 responsive materials and systems 109–114 reuse phases, embodied energy 63, 65 Rosenfeld, Arthur 3–6 RTSM see radiant time series method Russia 8–9, 84, 97 SageGlass 110–111 Saltaire, United Kingdom 138–139 Salt, Titus 138–139 Saudi Arabia 6, 51 scenario analysis 132–133

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Index

Sculpture Building and Gallery, Yale University 98 secondary energy see site energy second energy crisis 7–9 Sekisui House Head Office (Umeda Sky Building), Sakai City 79 self-awareness 75, 87–88, 90 self-organization 48–61 self-sustainability 48 sensible heat 100 sick building syndrome 45, 85–86, 126 Silent Spring 52 Singapore 42–43, 81, 147–152 Sino-Singapore Tianjin Eco-city 147–152 site energy building 6–7, 17–23, 25, 30, 33–34, 36–37 smart buildings 87–90, 96–116 smart-cities 66, 68–69, 87–90, 139 smart lighting 12 smart windows 12, 110 smog 34, 66, 75, 123, 125, 129–130 social aspects: future drivers and economics 76, 86–87, 92; green lifestyles 66–69; historical perspectives 1–2, 13; impacts of net zero building 42–54, 119, 122–127, 131–134, 137–152; life cycle assessments 126–127, 131–134, 142–152; metrics and assessments 26, 38; social-community building 51–54; suburban sprawl 66–69; unintended consequences 66–70 Socolow, Robert 4 Soddy, Frederick 1 sodium sulfate decahydrate 3 solar energy: 1930–1969: early solar house 2–3, 18; advanced materials 97, 101–103, 110–112; Brabantwoningen (Brabant House) 26–27; embodied energy 63, 66–70; evolution aspects 2–7; historical perspectives 2–5, 7–8, 18; impacts of net zero building 122, 144, 151; metrics and assessment 17, 20, 25–27, 30, 33; photovoltaics 9, 23, 25–27, 66–67, 112; Powerhouse Kjørbo, Sandvika, Norway 25; principles of zero energy building 17, 20, 25–30, 33; sustainability and self-organization 59–60; unintended consequences 59–60, 63, 66–70, see also renewable energy source energy 7, 19–20, 24–25, 30, 33–36 South America, regulatory drivers 84 South Korea 20, 34–36, 68–69, 78–81, 85 Soviet Union 8–9 sprawl 53, 61, 66–69, 121, 137–138

160

standards: building codes/standards 10–12, 75–85; California 10–12, 78; Minergie standard 8, 19; National Institute of Standards and Technology 9; Passive House standard 5–8, 18, 43–44, 77, 144 structures, nanotechnology 98–99 suburban sprawl 53, 66–69 super-insulation, evolution aspects 5–7 survival needs 87 sustainability: drivers of 76–78, 82–83, 87, 90–92; self-sustainability 48 Sweden 20, 64, 68, 84, 141–145, 150, 152 Switzerland 8, 19, 77, 104–105 system approaches, life cycle energy assessments 144 Technical Alliance 1 techno-cities 139–140 technology drivers 75–79, 82–83, 87–92 Telkes, Maria 3 TFM see transfer function method thermal response factor method (TRFM) 31–32 thermal storage 102, 104–108 thermochromic materials 110 thermodynamics 1, 13, 58, 100 Tianjin Eco-city, Singapore 147–152 Title 24, Californian standards 10–12, 78 Tokyo Climate Change Strategy 11 Tokyo Metropolitan Environmental Master Plan 11 Trainer, F. E. 61–62 transduction responsive materials 109–113 transfer function method (TFM) 31–32 transport energy 118–119, 123, 125 TRFM see thermal response factor method triple bottom line concept 131–132 UK see United Kingdom Umeda Sky Building, Sakai City 79 uncertainty analysis 132 unintended consequences of net zero building 58–74 United Kingdom (UK): asset value–market demand 46, 48; carbon-neutral development 138–140; energy and resource conservation 43; historical perspectives 1, 5; impacts of net zero building 43–47, 51, 138; metrics and assessments 34, 37; productivity and well-being benefits 44–46; regulatory drivers 84; social-community impacts 51; unintended consequences 65 United States (US): advanced materials and systems 96–97, 100, 103;

Index

cultural-social shifts 52; energy and resource conservation 43–44; future drivers and economics 77–78, 82, 85, 87–88, 92; historical perspectives 3–7, 9; impacts of net zero building 41–54, 117–119, 121, 128–129, 152; labor force building benefits 48–50; metrics and assessments 17, 19, 23, 34–36; productivity and well-being benefits 45–46; regulatory drivers 77–78, 82; socialcommunity impacts 51; unintended consequences 64–65, 68–69; West Berkeley Public Library, USA 21–23, 44, see also American. . .; North America University of Washington, Molecular/Nano Engineering Building 103 urbanisation/urbanism 117–134; carbonneutral development 68–69, 137–152; China 11–12, 42, 65–66; eco-districts and integrated frameworks 68–69; health impacts 122–126, 131–134; impacts of net zero building 117–126, 130–134, 137–152; land use impacts 121; lifestyles/societal impacts 66–69; sprawl 53, 61, 66–69, 121, 137–138 US see United States value–market demand, assets 46–48 vanadium oxide thermochromic smart windows 110 ventilation: advanced materials and systems 103, 105–107; evolution aspects 4; future drivers and economics 85–86; life cycle assessments 117, 131, 142; metrics and assessments 21, 23–26, 30; natural ventilation 21, 23, 25, 107

Wargocki, P. 45 wastewater 130, 144, 151 water: conservation 42–44, 46, 122–123, 125–130; life cycle assessments 126–130, 142–144, 147–152; quality 125, 130, 143–144 Weatherization Assistance Program 5 well-being benefits 42–47, 75, 85–87, 122, 147 West Berkeley Public Library, USA 21–23, 44 Wilkinson, Sara 63 wind flow impacts 122, 124 windows: advanced materials and systems 103–105, 109–111; electrochromic materials 12, 110–111; evolution aspects 4–5, 8; metrics and assessments 22–24, 30; phase-change materials 103–105; predicted impacts 46–48 wind turbines 17, 63, 144, 151 wireless access 75, 87–88 World Green Building Trends 2016 42, 46, 51 Yale University Sculpture Building and Gallery 98 Yom Kippur War 3 Yudelson, J. 54 ZEH see Zero Energy House Zero Carbon Building, Hong Kong, China 23, 28–30, 44 zero energy emissions 7, 17–20, 23–24, 28–30 Zero Energy House (ZEH) zero impact building (ZIB) 117–154

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