Aluminium: A Studio Design Guide [1 ed.] 9781859467060, 9781032648217

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Aluminium A Studio Design Guide

Michael Stacey

© Michael Stacey, 2023 Published by RIBA Publishing, 66 Portland Place, London, W1B 1AD ISBN 9781859467060 The rights of Michael Stacey to be identifed as the Authors of this Work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 sections 77 and 78. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of the copyright owner. British Library Cataloguing-in-Publication Data A catalogue record for this book is available from the British Library. Commissioning Editor: Liz Webster Production: Marie Doinne Design: Mercer Design, London Typesetting: Fakenham Prepress Solution Printed and bound by Short Run Press, Exeter Cover image: © Foster + Partners Endpapers: The Everyman Theatre, Hope Street, Liverpool, Haworth Tompkins (architect) with Alan Baxter Associates (structural engineers) and Watermans (environmental engineers), 2013. Image by Philip Vile. While every efort has been made to check the accuracy and quality of the information given in this publication, neither the Author nor the Publisher accept any responsibility for the subsequent use of this information, for any errors or omissions that it may contain, or for any misunderstandings arising from it. www.ribapublishing.com DOI: 10.4324/9781032648217

Contents About the Author

iv

Dedication

iv

Foreword

v

Sponsor

vi

Introduction

1

CHAPTER 1

A Light Metal

4

CHAPTER 2

Aluminium Pioneers

16

CHAPTER 3

Flexible

54

CHAPTER 4

Durability and Finishes

88

CHAPTER 5

Light and Strong

118

CHAPTER 6

Performative Façades

150

CHAPTER 7

Economical, Powerful and Sympathetic

176

CHAPTER 8

Sustainability

206

Notes

232

Index

238

Image credits

242

This book is dedicated to my grandchildren Phoebe, Nye, Cecily and Thea.

About the author Michael Stacey is convenor of Michael Stacey Architects and Professor of Architecture and Tectonics at the Bartlett School of Architecture, UCL. His professional life combines practice, teaching and research.  First published in the Architects’ Journal in 1985, he is the author of a wide range of publications and books and has also contributed a chapter on aluminium in the forthcoming book Materials: an environmental primer. Recent and current research programmes include: Towards Sustainable Cities: quantifying the in-use benefts of Aluminium in Architecture and the Built Environment with KieranTimberlake for the International Aluminium Institute and Living Architecture Systems with Philip Beesley Architects. Michael Stacey Architects’ aim is to contribute to people’s lives and the culture of contemporary society through an informed knowledge of humanity, study of architectural precedents and urban habitats, combined with a detailed understanding of materials and fabrication processes.

Acknowledgements The author would like to acknowledge the input into the research and publication of this book: Jim Eyre, Founding Partner of WilkinsonEyre. Laura Gaskell, Michael Ramwell, Jenny Grewcock and Philip Noones, architects, who formed the TSC research team at Michael Stacey Architects, with additional graphics by James O’Hara. Stephen Kieran, James Timberlake, Stephanie Carlisle, Efrie Friedlander and Billie Faircloth of KieranTimberlake. Helen Castle, Publishing Director of RIBA Elizabeth Webster, Senior Commissioning Editor, RIBA Publishing Chris Bayliss (Former Deputy Secretary General) Pernelle Nunez (Director of Sustainability) and Marlen Bertram (Director – Scenarios & Forecasts) of the International Aluminium Institute (IAI). All the clients, extruders, fabricators, fnishers, manufacturers, project directors, project engineers, project architects, smelters, referred to in the text, including Roberts Limbrick Architects.

Studio Design Guide Series Aluminium: a studio design guide is the second book in the RIBA Publishing series written by Michael Stacey. The frst Concrete: a studio design guide was published in 2011.

Foreword

It was clear to me, when we were students together at Liverpool University School of Architecture in the late 1970s, that Michael Stacey – the true intellectual in our year – was already developing his interest and talent for design to take him further than the rest of us in really looking hard at the properties of materials and how they could be put together. This was in a time when the new architecture that was most exciting to us was pushing technical boundaries and celebrating a highly refned use of metal, glass, and modular panels. Hi-tech was an optimistic aesthetic based on the advantages of of-site fabrication and a belief in the superiority of factory-made components. Perhaps the most memorable example of that time of his enthusiasm for fnding out how to do more with less was the fabric covered bamboo gridshell structure he erected in Abercrombie Square at the end of one year. There are as yet still no codes for the structural use of bamboo, so in professional practice it is no surprise that a material as versatile, strong and light as aluminium should feature so prominently in his career.  Professor Stacey’s thoroughness in his analysis of the manufacture and uses of aluminium in construction reminds us that there is much to learn about this particular material. As architects we should always look closely at the suitability of each of the components in our designs. What might start as a hunch or a vision about materiality is tempered by taking time to think about a material’s properties in its component form, particularly how it interacts or is combined with other materials. While as architects we have been used to paying attention to the basic functional properties of materials and how they are detailed – as well as, of course, the aesthetic qualities of appearance – we know now we must look more closely to the provenance of materials and their impact on the environment. Aluminium is the standout material for multiple re-use, and as it is deployed extensively in so many building types its future in construction is assured. 

Jim Eyre, OBE, RIBA, Founding Partner of WilkinsonEyre

v

Sponsor

Thank you to Barley Chalu for their support and sponsorship of the book.

Barley Chalu is a leading UK-based supplier, specialising in the quality and fnish of architectural aluminium profles. It ofers services in the polyester powder coating, polyamide and polyurethane thermal break, stripping, pre-anodising, anodising and electrocolouring of aluminium: www.barleychalu.co.uk

Introduction

Aluminium can provide beauty and persistence. The versatility of aluminium and its alloys in production, fabrication and fnishes delivers high-quality and durable architecture that ofers signifcant in-use carbon benefts. Aluminium can contribute towards the creation of sustainable cities – a key task now that over half of humanity lives in urban areas.1 Norman Foster has suggested that the city is the greatest invention of humankind: ‘The future of society is cities; but what makes a city work? The city is about values, about aspirations, they are enlightening as well as ofering prosperity.’2 It should not be a concern that cities provide the majority of homes for humanity. However, humankind needs to hone its skills in designing and developing the urban realm within climate change targets of carbon usage, while protecting the overall biodiversity of planet Earth. Aluminium has become a vital yet background material of our contemporary cities. Based on data from 2020, the carbon footprint of UK cities is currently lower than rural areas – for London it is 3.2 tonnes CO2e per person annually, and the UK average is 6.2 tonnes CO2e per person annually, whereas the US average is 15 tonnes CO2e per person annually.3 While reviewing the role of aluminium in the construction of the built environment and how it can be marshalled as an ongoing resource for humankind, it is important to use a clear and efective defnition of sustainability. For architecture and the built environment, sustainability is the balancing of economic, ecological, political and cultural objectives within a spatial project.4 Thus, sustainable development ‘seeks to meet the needs and aspirations of the present without compromising the ability to meet those of the future’, stated Gro Harlem Brundtland in 1987.5 This book takes a long view of the built environment and is based on practice, research, inspection and testing, including the Towards Sustainable Cities (TSC) research programme, undertaken by the author with Michael Stacey Architects and KieranTimberlake for the International Aluminium Institute. The overriding theme that emerged from the TSC Symposium at the Royal Botanic Gardens, Kew, in 2016, was as follows: Application of aluminium in architecture and the built environment should not seek wholesale replacement or displacement of other constructional materials. Instead, the aim should be to maximise the potential use of aluminium via an active and collaborative dialogue between end users, notably architects, engineers and product designers, with the aluminium industry; from smelters, extruders, fnishers and fabricators.6 In our multi-material world, how we select and combine materials to create architecture and infrastructure is key to achieving sustainability. We should do this using precedents, long-term research and life cycle analysis (LCA), combined with the skills of integrated design teams. The contribution of aluminium in creating sustainable cities is demonstrated by the case studies set out in this book, which serve humankind well. Aluminium provides high-performance components that ofer durability and long-term service. In your hands, it is a servant of sustainability.

1

0.1 The River Thames in central London – aluminium has become the background material of our contemporary cities.

CHAPTER 1

A Light Metal Aluminium is a light, ductile and highly corrosion-resistant metal and is, in itself, unchanged since it was identifed by Sir Humphry Davy in 1808, as a constituent of alumina.1 Aluminium was frst produced in signifcant quantities by Hans Christian Ørsted in 1825, and in purer form by Friedrich Wöhler in 1827. Aluminium is the third most abundant material in the Earth’s crust and the most abundant metal. Aluminium is 8% of the Earth by mass, typically found in the form of bauxite.2

1.1 (opposite) Billets of 6063-H aluminium alloy.

The cost of producing aluminium was very signifcantly reduced towards the end of the 19th century by three factors: the Hall-Heroult electrolysis process, the Bayer process and the reduction in the cost of producing electricity as it became wildly adopted. The Hall-Heroult electrolysis process was simultaneously invented in the USA and France in 1886 and named after its three inventors, Charles Martin Hall, with his sister Julia Brainerd Hall, and Paul Heroult. The Bayer process for converting bauxite into alumina was invented by Karl Josef Bayer in 1888. In the 1850s, the cost of one kilogram of aluminium produced by chemical reduction was over $70, reducing to $33 by 1886 and only 40 cents in 1915.3 Alloyed with other metals, such as copper, it has become the frst-choice material for many contemporary applications. Aluminium has seven primary qualities that make it ideal for use in applications within architecture and the built environment. It is: • durable • recyclable • fexible • light and strong • efcient • economical • sympathetic. It is also very conductive, which in many architectural applications is detailed out by combining it with highly insulating materials.

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1.2 Graph of the frst use of aluminium alloys in aircraft and aerospace applications, 1910 to 2010, based on Alcoa data.

100

Key

7055-T77 7055-T79 777 A380

90

Upper Wing 7178-T651 707

80 7075-T651 B29

70

60

2024-T3 DC3 Wings, Fuselage, Other

Yield Strength, ksi (Typical, L-Direction) 50

7150-T651 757/767

2324-T39 737

7075-T7351 DC10

A6013-T6 A318

2224-T3 737

Lower Wing 2099 A380

2324-T39 Type II 777

2097 Thick Plate F16 Bulkhead

7050-T7451 A6

2020 RA5C Vigilante Wing Plate

2017-T4 Junkers F13 Wings, Fuselage, Other

7085-T7X51 A380

7150-T6151 A310/MD11 7075-T7651 L1011

7055-T76 A380

7150-T7751 C17

2524-T3 777

2026-T3511 A340-500/600

Fuselage Skin

Thick Plate

C4333-T351 A340-500/600

Al-Li Alloys

40

30 1910

1920

1930

1940

1950

1960

1970

1980

1990

2000

2010

Year First Used in Aircraft or Aerospace

Aluminium alloys are set out in ‘International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys’, issued by the Aluminum Association of the USA.4 This is a four-digit system in which the frst digit, from 1 to 9, indicates the principal alloying element. This system is used in British and European Standards, for example BS EN 575:1996, Aluminium and Aluminium Alloys.5 The application of aluminium in construction, and even the material itself, continues to be developed as new technical discoveries are made and exploited. The development of new alloys can ofer increased performance and/or workability (see Figure 1.2 for the development of new alloys for aerospace applications). A new alloy can be registered with the Aluminum Association in under 90 days.6 1.3 1100 aluminium alloy food tray, which has been washed prior to recycling.

Aluminium alloys 1000 series alloys are 99% aluminium or higher purity. Common applications include electrical power lines, food packaging and foils. 1350 alloy is often used for electrical applications and 1100 alloy for food packaging trays and foils for vapour check layers and vapour barriers. Aluminium foils were frst produced in Kreuzlingen, Switzerland, in 1910.7 Copper is the primary element added to 2000 series alloys, but typically not more than 5%. 2000 series alloys can be strengthened by heat treating, which is discussed below. This alloy series provides toughness and high strength; however, the presence of copper limits its corrosion resistance and therefore components should either be protected by a coating system or by cladding with a high-purity aluminium alloy. 2024 alloy, with 3.8 to 4.9% copper,

6

A L I G H T M E TA L

1.4 The Boeing 247D, 1933, is regarded as the frst 2000 series aluminium alloy semimonocoque airliner and utilises cantilever wings.

is often used in aircraft assemblies. The frst aircraft built from this series of aluminium alloys was the Boeing 247D, introduced in 1933.8 It has a semi-monocoque structure (monocoque is the French word for single shell, such as a hen’s egg). A semi-monocoque structure uses the skin structurally but is stifened with internal ribs.

1.5 Aluminium Coca-Cola cans have a 3004 aluminium alloy deep-drawn body and a 5182 alloy cap.

Manganese is the primary element added to 3000 series alloys, with typically between 0.3 and 1.5%, and magnesium is also used, between 0.2 and 8%, depending on the specifc alloy. 3000 series alloys ofer reasonable strength and are readily worked. The body of an aluminium drinks can is typically formed from 3004 alloy and the ends are made from 5182 alloy. Incidentally, Coca-Cola was frst produced in 1886, the same year that the Hall-Heroult process was invented. Silicon is the primary element added in 4000 series alloys, which lowers the melting point of the aluminium. In 4043 alloy, between 4.5 and 6% silicone is used. Typically produced as a wire, 4043 is used for welding 6000 series components in automotive and structural applications. In 5000 series alloys, the primary element added is magnesium. Between 4 and 4.9% magnesium is used in 5083 alloy. The Aluminum Association advises that 5000 series alloys ofer ‘moderate to high strength characteristics, as well as good weldability and resistance to corrosion in the marine environment’.9 5000 series alloys are often used for sheet products. 5005 anodises well and is used in architectural applications, 5083 in marine environments and, as noted above, 5182 is used to make drinks can lids.

1.6 Audi’s welded aluminium space frame of the Audi A8, introduced in 1994. It was the frst mass-production car to utilise an aluminium structure to reduce its overall weight while providing structural rigidity.

In 6000 series alloys, the primary elements added are magnesium and silicon, which combine to form magnesium-silicide within the alloy. This series is very versatile, ofering excellent corrosion resistance and good strength, as well as being heat treatable, highly formable and weldable. 6000 series alloys are readily extruded and are often used in structural applications, as shown in Chapter 5, and for relatively complex sections used to fabricate windows and 7

A LU M I N I U M : A S T U D I O D E S I G N G U I D E

curtain walling. 6063 anodises well and is the most commonly used alloy. 6082 has two-thirds the tensile strength of steel; however, this alloy has variable grain structure, which can be visible on the surface of the components after anodising. If appearance is critical, it may be necessary to brighten the section by manual or electrolytic polishing before anodising. Hydro has developed a new 6000s alloy for high-strength applications in automobile design. It has been researched and developed as an alternative to 7000s alloys, which are more difcult to extrude and relatively more expensive. Hydro’s test shows that the new alloy has a yield strength above 350MPa and 10% elongation.10 1.7 Silicone-bonded 6000 series alloy-framed fush curtain walling of 240 Blackfriars Road, London, by Allford Hall Monaghan Morris, 2014.

1.8 Schüco AWS 75SI, tripleglazed window system using 6000 series alloy extrusions, insulation and polymer thermal breaks.

8

A L I G H T M E TA L

7000 series alloys utilise zinc, often in combination with magnesium, copper and chromium; these alloys are heat treatable and ofer high strength. 7050 alloy comprises 5.1 to 6.4% zinc, with 2.1 to 2.9% magnesium, 1.2 to 2.0% copper and 0.1 to 0.25% chromium. Manganese, silicon, iron and nickel are also present in this alloy. 7050 and 7075 alloys are widely used by aircraft industries (the 7000 series was often known as aerospace grade).11 7000 alloys are increasingly being used in bicycle manufacture, and the exclusive association with aerospace is diminishing as other relevant lightweight applications are found, which includes Apple iPhones. Apple developed a new 7000 series alloy to produce the case of the iPhone 6, launched in 2014. 7005 alloy is used to extrude the weldable sections of lightweight yet stif mountain bikes. 1.9 The case of Apple’s iPhone 6 is made from a new aluminium alloy in the 7000 series.

1.10 The author’s 25-year-old Marin mountain bike, with a welded 7005 aluminium alloy frame. Note the precise yet visible welding of the aluminium frame.

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1.11 7000s aluminium alloys are used in the assembly of the Airbus A380 jetliner; it is 80% aluminium alloys. (Photographed at the Paris Air Show, 2015.)

8000 series aluminium alloys use a diversity of principal alloying elements. For example, in 8001 alloy the principal alloying element is nickel. It is zinc for 8007 alloy, iron-vanadium for 8009 and 8022 alloys, cerium for 8019 alloy, tin for 8081 and 8280 alloys, and lithium for 8024 alloy. For 8011 alloy, iron-silicon is the principal alloying element. Typical uses of 8000 series alloys include the following: • 8001 alloy is used for corrosion resistance • 8081 and 8280 alloys are used to make bearings • 8024 alloy is typically used in aerospace applications • 8011 alloy is used to make heat exchangers. 9000 series is being held in reserve for future alloys of aluminium. Aluminium alloys can also be placed in two groups: heat-treatable alloys and non-heattreatable alloys. The heat-treatable alloys are: • 2000 series • 6000 series • 7000 series. Non-heat-treatable alloys are: • 3000 series • 4000 series • 5000 series. 10

A L I G H T M E TA L

1.12 Welded mill-fnish aluminium oil rig pedestrian bridge, using a combination 5083-H321 and 6061-T6 alloys, designed and fabricated by MAADI Group, 2014, being installed, published with permission of the oil extraction company.

The Aluminum Association describes the process of heat-treating alloys as ‘strengthened by solution heat-treating, where the solid, alloyed metal is heated to a specifc point. Next the alloy elements (solute) are homogenously distributed, forming a solid solution. The metal is subsequently quenched, or rapidly cooled, freezing the solute atoms in place. These atoms consequently combine at room temperature (natural aging), or in a low-temperature furnace (artifcial aging) creating a fnely distributed precipitate,’ and thus an aluminium meeting the required performance.12 Non-heat-treatable alloys are strengthened through cold working, which occurs during rolling or forging, building up dislocations and vacancies in the structure; inhibiting movement of atoms relative to each other increases the strength of the alloy.

The Temper of Aluminium Alloys A temper is a stable level of mechanical properties produced in a metal or alloy by mechanical or thermal treatment(s). Following the four-digit code of wrought or cast aluminium alloy, a letter followed by numbers designates its temper. F is as fabricated, cold working is H, for example H1 is strain hardened only to obtain the desired strength without supplementary heat treatment. Heat treatment is designated by T and the basic heat treatments are designated T1 to T9. For example, an oil rig pedestrian bridge, designed and fabricated by MAADI Group, is in part fabricated from 6061-T6 aluminium alloy extrusions. This is a specifc 6000 series alloy that has a temper of T6, meaning it was solution heat treated and then artifcially aged. For a complete description of temper designation, see Properties of Aluminium and its Alloys (2014).13 11

A LU M I N I U M : A S T U D I O D E S I G N G U I D E

Table 1.1 Basic cold-working designations of aluminium.

Table 1.2 Basic heat-treatment designations of aluminium.

Symbol

Description

O

Annealed, soft

F

As fabricated

H12

Strain-hardened, quarter hard

Н14

Strain-hardened, half hard

H16

Strain-hardened, three quarter hard

H18

Strain-hardened, fully hard

H19

Strain-hardened, extra hard

H22

Strain-hardened, partially annealed, quarter hard

H24

Strain-hardened, partially annealed, half hard

H26

Strain-hardened, partially annealed, three quarter hard

H28

Strain-hardened, partially annealed, fully hard

H32

Strain-hardened, and stabilised, quarter hard

H34

Strain-hardened, and stabilised, half hard

H36

Strain-hardened, and stabilised, three quarter hard

H38

Strain-hardened, and stabilised, fully hard

Heat Treatment T1

Cooled from an elevated temperature, shaping process and naturally aged to a substantially stable condition

Т2

Cooled from an elevated temperature shaping process, cold worked and naturally aged to a substantially stable condition

Т3*

Solution heat-treated, cold worked and naturally aged to a substantially stable condition

T4*

Solution heat-treated and naturally aged to a substantially stable condition

T5

Cooled from an elevated temperature shaping process and then artifcially aged

T6*

Solution heat-treated and then artifcially aged. Applies to products which are not cold worked after solution heat-treatment

T7*

Solution heat-treated and then artifcially aged. Applies to products which are artifcially aged after solution heat-treatment

T8* Т9*

Solution heat-treated, cold worked and then artifcially aged Solution heat-treated, artifcially aged and then cold worked

* Some 6000 or 7000 series alloys attain the same specifed mechanical properties whether furnace solution heat-treated or cooled from an elevated temperature shaping process at a rate rapid enough to hold constituents in solution.

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Duraluminium One of the key pioneers of aluminium alloys was Alfred Wilm, a German metallurgist. In 1903, he was experimenting with an aluminium alloy with 4% copper, seeking an alloy that was as strong as mild steel. Having become frustrated that quenching the alloy had no efect on its strength and it was still easily bent, Wilm left for a river cruise – according to materials scientist Mark Miodownik. On Wilm’s return, days later, the aluminium had become stronger: he had accidentally discovered age hardening.14 By 1909, he had developed and patented Duraluminium, an age-hardened aluminium alloy with copper, magnesium and manganese. Its properties are close to mild steel but one-third the weight. John Dwight observes, ‘It was the start of what we now term the 2000 series alloy group.’15 Dwight notes: A scientifc explanation of age-hardening did not appear until 1920, soon after which a second kind of age-hardening alloy emerged, namely the Al-MgSi [aluminium, silicon and magnesium] type. This alloy group (the present day 6000 series) has a tensile strength in its strongest version of some 300N/mm2, and is thus generally weaker than the 2000 series. But it has other features that have since led it to become the ‘mild steel’ of aluminium.16 Thus, age hardening is like many discoveries: experimentation and tactile knowledge preceded scientifc theory. Dwight explains, ‘By 1939 all of today’s main alloys had thus arrived except one, namely the weldable kind of 7000 series alloy. This was actively developed after the [Second World] War.’17 Yoshio Baba notes that the frst development of 7075 alloy, which has strength characteristics comparable to steel, was in Japan during the Second World War by Sumitomo Metal, in 1943.18

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1.13 Timeline of aluminium up to the Jet Age.

1800

1808

1821

1827 1825

1855 1854

1858–60

Aluminium is discovered by Sir Humphry Davy as a constituent of alum, in England

Pierre Berthier discovers bauxite ore in Les Baux-de-Provence, southern France

Friedrich Wölher isolates aluminium, in Germany HC Ørsted produces signifcant quantities of aluminium, in Denmark

Aluminium spoons and forks used by visiting dignitaries at the Court of Napoleon III, in France Henri Étienne Sainte-Claire Deville enhances Wölher’s method of isolating aluminium and chemical production of aluminium commences in France

Aluminium casting of Diane de Gabies by Paul Morin et Cie, in France

A L I G H T M E TA L

1960

1957 1954

1931

1934

1940

1950s 1949

Development of anodising and aluminium extrusion processes

Empire State Building, New York, USA, by William F. Lamb: cast aluminium spandrel panels

Anodised aluminium windows installed at University of Cambridge Library, architect Sir Giles Gilbert Scott

Anodised aluminium windows installed at New Bodleian Library, architect Sir Giles Gilbert Scott

UN Secretariat Building, New York, clad in aluminium curtain walling, executive architects Harrison & Abramovitz Pioneering of aluminium curtain walling in USA Unitised aluminium curtain walling by Jean Prouve for Federation du Batiment Ofce, Paris

Jean Prouve designs extruded aluminium curtain walling for CIMT Jean Prouve’s Aluminium Centenary Pavilion is built to celebrate the 100th anniversary of the industrial production of aluminium in France Alcoa Building ‘The worlds frst aluminum skyscraper’, Pittsburgh, by Harrison & Abramovitz

1920s

Otto Wagner’s Postsparkasse, Vienna – cast and sheet aluminium Alfred Wilm invents Duraluminium in Germany First powered fight by Wright brothers, Kill Devil Hills, USA, using a cast aluminium engine Aluminium is the key material in the interior of St Mary the Virgin, Great Warley, Essex

1953

1906 1903 1903 1902

1950

1897 1895 1892 1891 1890 1888 1886

Aluminium sheet cladding of the cupola of the church of San Gioacchino, Rome Aluminium ceiling installed at Church of St Edmund, King & Martyr, Derbyshire, Fenny Bentley Cast aluminium sculpture of Eros at Piccadilly Circus, London First aluminium boat fabricated in Switzerland First use of aluminium for overhead electric power cables Pittsburgh Reduction Company founded to develop the Hall-Heroult process Bauxite refning, the Bayer process is invented & patented by Austrian scientist Karl Josef Bayer Hall-Heroult process – afordable volume production of aluminium Invented by, Julia Brainerd Hall and Paul Heroult Cast aluminium pyramid cap to the Washington Monument, in USA 1884

CHAPTER 2

Aluminium Pioneers There is a rich history of the use of aluminium to assemble buildings, dating back to 1895. All the examples presented in this book are of high-quality architecture that incorporate a signifcant use of aluminium. The vast majority of the projects are still in use. The earliest recorded use of aluminium within the realm of architectural construction is at the Church of St Edmund, King and Martyr, Fenny Bentley, near Ashbourne in Derbyshire. The ceiling of the Beresford family chapel in the northwest corner of the church is made of decorated aluminium panels with additional wooden bosses, ‘carved by members of the rector’s wood-carving class, one of which shows the date of 1895’, when the ceiling was installed.1

2.1 (opposite) The aluminiumclad dome of San Gioacchino, Rome, by Rafaele Ingami, 1897.

2.2 Aluminium ceiling panels painted by Alice M Erskine in the Church of St Edmund, King and Martyr, Fenny Bentley, Derbyshire, installed in 1895.

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The painted aluminium panels present a remarkable set of components for this time period. In 1888, ‘the price of aluminium produced in Stoke-on-Trent was £3,000 a ton, with a production rate of about 85 tons per year’.2 The introduction of the electrolytic process in the decade after 1886 began to reduce production costs. It is therefore possible that the aluminium sheets were ‘pre-production prototypes given to the church by AS Bolton of Oakamoor, a director of the British Aluminium Works of Milton in Stoke-onTrent’.3 The ‘30 panels of 99.1% purity aluminium’ are thought to be ‘0.033" [0.84 mm] thick’.4 The aluminium shows very little sign of ageing and there has been no record of maintenance since it was installed 120 years ago. The vibrant ceiling panels, painted by Alice M Erskine in 1895, still display with clarity the detail with which they were originally painted. San Gioacchino in Prati Church in Rome was designed by the architect Rafaele Ingami. Construction of San Gioacchino began on 1 October 1891 and the building opened to the public on 20 August 1898.5 The dome of this church, completed in 1897, is the earliest extant example of external aluminium cladding. The 1.3mm-thick aluminium cladding was selected for its lightness, durability and economy. The aluminium cladding of the dome has been inspected and tested during its more than 120 successful years of service. San Gioacchino is a large church, on a Latin cross plan, with a central dome. Its Neoclassical form is probably due to Pope Pius IX banning ‘the modern’ in his Syllabus of Errors in 1864.6 The dome is a lightweight construction with a steel structure, which is clad on the outside in 1.3mm-thick aluminium sheets. The internal skin is also a lightweight panel construction and it is reasonable to suggest that this is also aluminium sheet, like the aluminium ceiling in St Edmund, King and Martyr that predates San Gioacchino by three years. The aluminium cladding of the dome of San Gioacchino remains in excellent condition to this day. The cladding of this dome has regularly been inspected and tested during its life: EW Skerrey reported in 1982, ‘Examination in 1938 and 1953 indicate very little damage to the metal with pitting less than 0.1mm (0.004”).’7 Skerrey observed that the aluminium sheeting is 98.8% pure, whereas ‘the lowest purity in use today is 99.0%’.8 Ingami selected aluminium to clad the dome because it was lightweight, durable and economical in comparison to a lead sheet roof.

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2.3 The 1.3mm-thick aluminium panels of the dome of San Gioacchino are still in excellent condition, photographed in 2013.

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2.4 The internal cladding of the dome of San Gioacchino is also in excellent condition, photographed in 2013.

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St Mary the Virgin is a Grade I listed parish church, designed by Charles Harrison Townsend in collaboration with the sculptor and interior designer Sir William Reynolds-Stevens.9 It is located in Great Warley, Essex. Completed in 1902, this is one of only three Art Nouveau church interiors in the UK. This church possesses an aluminium interior, celebrating the material for its value, durability and decorative character. The apse of the church sparkles with a hemispherical dome clad in aluminium, deployed like gold leaf. This is ofset by vine leaves embossed in aluminium and cherry-red grapes. The nave is articulated by arches that carry embossed aluminium organic bas-reliefs, which are all signed by Reynolds-Stevens. Townsend also designed the Whitechapel Art Gallery (1899) and the Horniman Museum (1901), both in London, and was one of England’s leading Art Nouveau architects. Although this interior is characteristically Art Nouveau, it also demonstrates Arts and Crafts infuences – particularly in the palette of other materials selected, including beaten copper for the pulpit, with brass and even mother of pearl in the rood screen. AL Baldry’s review of the church in The Studio magazine (1905) considered aluminium to be an appropriate and durable part of this material palette.10

2.5 St Mary the Virgin, Great Warley, Essex, by Charles Harrison Townsend, 1902.

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2.6 The nave of St Mary the Virgin has an aluminium-rich Art Nouveau interior by Sir William Reynolds-Stevens. Note the embossed aluminium panels on the arches, designed and made by Reynolds-Stevens.

2.7 Detail of the aluminiumleaf-clad hemispherical dome of the apse behind the altar, at St Mary the Virgin.

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The expense of aluminium production before the Hall-Heroult process meant that fne and decorative arts led the pioneering use of aluminium. William Alexander and Arthur Street cite Napoleon III’s prestigious all-aluminium dinner service.11 The oldest known aluminium sculpture is a one-third scale copy of a classic marble sculpture named Diane de Gabies, which was rediscovered in Gabies in Italy. The cast aluminium version was produced by Fabrique d’Aluminium, Paul Morin & Cie at Nanterre, France, between 1858 and 1860.12 This sculpture predates the cast aluminium pyramid that caps the Washington Monument, completed in 1884 (see Figures 2.9 and 7.40). This aluminium pyramid also serves as the point of the lightning conductor of this highly symbolic American monument. Nine years later, in 1893, the cast aluminium sculpture known as Eros, dedicated to Lord Shaftsbury, was erected at Piccadilly Circus, London.

2.8 Diane de Gabies, 1858–60, is the oldest extant aluminium sculpture in the world.

2.9 The Washington Monument was completed on 6 December 1884 with a 229mm-tall cast aluminium pyramid that also serves as the point of the lightning conductor.

2.10 Known as Eros, this cast aluminium sculpture by Alfred Gilbert is Eros’s brother Anteros. It was unveiled in Piccadilly Circus, London, on 29 June 1893.

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The Postsparkasse or Austrian Postal Savings Bank in Vienna was designed by Otto Wagner and completed in 1906. Postsparkasse is one of the masterpieces of early 20th-century architecture. Nikolaus Pevsner considered it an exemplar of the development of Modern architecture as it demonstrated an ‘artistic economy and clarity, of which there is virtually no parallel in this period’.13 Famous for its use of aluminium in its façades, it is the frst example of a world-class work of architecture that extensively uses aluminium in its construction, interior and furnishings, at a time when the total world production of aluminium was only 6,000 tonnes.14 The Postsparkasse was founded by Dr Georg Coch in 1893 based on the model of British savings banks. It rapidly became very successful and outgrew the rooms provided for it in a Dominican monastery. This resulted in a competition in 1903, won by Wagner. The site, a complete city-block just inside the Ringstrasse in Vienna’s city centre, had previously been identifed by Wagner as the site for a bank in his 1892 strategic plan for the development of Vienna.

2.11 Postsparkasse, Vienna, by Otto Wagner, 1906, viewed from Georg-Coch-Platz.

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2.12 (opposite) The main banking hall of the Postsparkasse.

2.13 The 4.3m-high cast aluminium sculpture Winged Victory, by Othmar Schimkowitz, standing on the projecting cornice of the Postsparkasse.

2.14 Drawing of the Wright Flyer, 1903. The National Air and Space Museum in Washington, DC, observes: ‘The Wright Flyer was the product of a sophisticated fouryear programme of research and development conducted by Wilbur and Orville Wright, beginning in 1899.’15

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2.15 The aluminium-clad columns of the Postsparkasse, with spun aluminium bases, support the entrance canopy. The handrails are also made of aluminium.

2.16 Otto Wagner’s cutaway perspective of the front façade of the Postparkasse.

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The cornice of the entrance façade is completed by 4.3m-high cast aluminium Winged Victories by the sculptor Othmar Schimkowitz. He also sculpted the six cast aluminium swags and laurel wreathes at the corners of the bank. In the year Wagner won the Postsparkasse competition in Vienna, proposing the extensive use of aluminium, the Wright brothers, Orville and Wilbur, in the USA, achieved the frst powered fight, in the Wright Flyer, with Orville at the controls, on 17 December 1903. This aircraft was powered by a petrol engine, with a lightweight cast aluminium engine block – the benefts of aluminium were being taken up by many felds of human endeavour, including architecture and transport, efectively at the same time. The frieze above the entrance facing the Ringstrasse is flled by the name of the bank, Österr, Postsparkasse, in delightful Art Nouveau lettering, punched from aluminium sheet. The steel columns supporting the scalloped translucent glass canopy sheltering the entrance are clad in aluminium. The head and base of the cladding are formed from aluminium spinnings. Construction of the Postsparkasse started on 12 July 1904 and was completed in 16 months – a key to delivering this speed of construction was the bolted cladding of 100mm-thick granite to the base and frst foor and 20mm Sterzing marble for the next four foors and cornice. Siegfried Gideon believed that the façades were fxed with aluminium bolts. He observed that Otto Wagner ‘strongly stressed the function of the wall as a plain surface. The façade of this building is clad with marble panels; and these are fastened down with solid aluminium bolts, the heads of which are clearly visible.’16 The 17,000 bolts used in the façade are steel protected from corrosion by lead with aluminium caps. Wagner selected this technique to facilitate rapid construction; he also thought that the layered façade referred back to the cladding of buildings such as the Pantheon in ancient Rome, where marble is used as a facing to brickwork. This is characteristic of Wagner’s approach to architecture after the publication of his book Modern Architecture in 1895; he embraced tradition and change, working with clarity within the city, yet using modern materials, particularly aluminium, which was almost unknown in architecture at the time.17 The central portion of the marble façade above the entrance is more densely studded with aluminium-capped bolts to emphasis the entrance. Wagner consciously references a strongbox or treasure chest as a metaphor for a reliable bank. Popularly, the building soon became known as the Pincushion. Three years from competition to completion remains a tight timescale for the delivery of a major work of architecture, even in the 21st century.

2.17 Aluminium-capped bolts showing the longevity of aluminium compared to the rusted steel.

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The plan of the Postsparkasse has a simple directness that makes it readily navigated by customers. The central space is the main banking hall, which has a glass foor to provide light to the foor below and is roofed by a glass-and-steel double roof. The inner layer of the roof is of translucent glass that provides a gentle and even daylight. This space was originally warmed by the tubular aluminium heaters clearly articulated from the walls. Following the refurbishment of the bank in 1995, these have been converted to air extractors, in essence they retain their original role. The steel columns of the banking hall are clad in aluminium. This cladding was removed during the restoration work in 1995 to enable the corroded steel to be treated and painted. The aluminium cladding was simply cleaned and reinstated.18

2.18 (opposite) Aluminium heaters of the Postparkasse’s main banking hall, now functioning as air extractors.

The Postsparkasse is an exemplar of gesamtkunstwerk: total work of art. Wagner engaged in designing everything in the bank, including carpets, counters and clocks; all the interiors, including furnishings and fttings, were designed by Wagner’s ofce. He made Thonet chairs more durable by the use of aluminium feet and articulated the function and structure of the chairs with further aluminium details. The Postsparkasse was completed in 1906, less than 100 years after the identifcation of aluminium by Sir Humphry Davy. Although aluminium was a relatively new material to architecture, Wagner had a very clear idea of its durability. Did this refect his own observations of samples or was he advised by scientists at Austrian universities? At the end of the 19th century, Vienna was noted as a city transformed by science. Wagner had links to this intellectual community as he was Professor of Architecture at the Vienna Academy of Fine Art. Not surprisingly, following the success of the Postsparkasse, Wagner used aluminium on subsequent projects in Vienna, including the Döblegergass 4 Apartment Building, in 1912, and the Second Wagner Villa in 1913. Jan Tabor observes that Wagner’s use of aluminium on the Postsparkasse was ‘an unusual building material at the time – and even today’.19 Wagner thought that ‘what is impractical cannot be beautiful’, a lesson many contemporary digital architects could learn from.20 The design of the Postsparkasse by Wagner represents a hinge in the history of aluminium in architecture. With its cast aluminium sculptures and decorative sensibility, it is part of the early decorative use of aluminium, a phase in which aluminium was enjoyed as an exotic and rare material. The Postsparkasse, however, also signifes the start of the use of aluminium as an afordable, durable and repeatable building component, where components are used hundreds or even thousands of times to produce architecture of the highest quality, delivered by economical and rapid construction processes.

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The Empire State Building, New York, designed by William F Lamb, of Shreve, Lamb & Harmon, was completed in 1931 and has a steel frame clad in vertical bands of masonry with limestone alternating with steel-framed windows and cast aluminium spandrel panels. A wythe (a single leaf of masonry) forms the wall behind the cast aluminium spandrel panels, which were described as ornamental, yet have a role like a contemporary rainscreen panel. Prefabrication of components enabled the construction to be completed in one year and 45 days. In 1993, the Empire State Building was refurbished, during which all 6,400 corroded steel windows were replaced; the original aluminium spandrel panels did not require refurbishment. Cast aluminium was used extensively between the two World Wars, especially in North America, as cladding and decoratively.21

2.19 Isometric drawing showing the detail of the assembly of the windows and cast aluminium spandrel panels of the Empire State Building, by William F Lamb, of Shreve, Lamb & Harmon.

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2.20 The Empire State Building, New York, by William F Lamb, 1931, viewed from Fifth Avenue.

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The University of Cambridge Library, designed by Sir Giles Gilbert Scott, was constructed between 1931 and 1934. This impressive brick-built library is glazed exclusively with anodised aluminium windows. Some suggest it is reminiscent of Sir Giles Gilbert Scott’s industrial architecture that includes Bankside Power Station in London, which is now Tate Modern. The central tower of the library is 48m high. The anodised aluminium windows, with clear single glazing, were manufactured by James Gibbons in Wolverhampton and are still in good working order. In the ofces, the windows have had openable secondary glazing added to improve their thermal performance. In the library’s circulation spaces, the windows are in their original condition from the 1930s. Gilbert Scott used the same window manufacturer to produce the anodised aluminium windows of the New Bodleian Library in Oxford, in 1940. This project is discussed in Chapter 4. 2.21 The University of Cambridge Library, by Sir Giles Gilbert Scott, completed in 1934.

2.22 Anodised aluminium windows of the University of Cambridge Library.

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2.23 The Dymaxion House, designed by Buckminster Fuller, under construction in 1946.

The Dymaxion House, designed by engineer Richard Buckminster Fuller, was completed in 1946 at Wichita, Kansas. It was part of a series of dymaxion experiments dating back to 1927. Buckminster Fuller considered lightweight (minimal mass) to be the key factor in the design of architecture. He applied four key criteria to the design of the Dymaxion House at Wichita: 1. Achieve minimum weight by the minimum use of material. 2. Reduce wind loading by shape and concealed detailing. 3. Achieve a maximum enclosure of volume with a minimum surface. 4. Apply fne tolerances necessary in metal-based assemblies.22 Therefore, the Dymaxion House makes extensive use of aluminium extrusions as framing and aluminium sheeting as cladding. This is combined with stainless-steel rods in the form of a masted circular structure, which is internal to the cladding. The AIROH aluminium bungalow resulted from a UK central government initiative in 1944 to bridge the anticipated post-Second World War housing shortage. One system of prefabricated housing, or prefabs, was developed by the Aircraft Industries Research Organisation on Housing (AIROH). The AIROH prefab manufactured in 1948, shown in Figure 2.24, was re-assembled at the Museum of Welsh Life at St Fagans, near Cardif, in 1998. The specifc model is a Type B2 AIROH house and it was one of 40 prefabricated three-bedroom homes built by the aircraft industry for Llandinam Crescent in Cardif. There is also a group of 30 aluminium prefabs in Redditch, which were saved from demolition in 2002. 35

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2.24 An AIROH aluminium prefabricated house, originally constructed in 1948 and re-assembled at St Fagans, Wales, in 1998; photographed in 2013. 2.25 One of the four sections of an AIROH prefabricated house being craned in at the From ‘War to Peace exhibition’, June 1945, behind Selfridge’s, London.

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The AIROH prototype house was built at the factory of the Bristol Aircraft Company (BAC), one of the members of the AIROH.23 Designed to take up spare capacity in the aircraft industry factories that had once assembled Spitfres, the AIROH prefabs were produced in four sections, which were bolted together on site. In total, 54,500 AIROH houses were manufactured, about one-third of all post-Second World War prefabs. These modest detached houses with gardens proved very popular and far exceeded their predicted life expectancy of 10 years. Why were these homes given such a short life expectancy? This was politically expedient as the houses were provided by central government. Under Scottish Building Regulations, the life expectancy of an AIROH prefab was rated as 60 years.24 On visiting the AIROH prefab at St Fagans, the only overt aluminium detail is the aluminium canopy that shelters the front and back door from wet weather. However, each house used aluminium extensively. Wall panels are aluminium sheets riveted to aluminium extrusions, flled with an aerated cementitious insulation, with plasterboard internal linings. The roof is an aluminium truss, clad inside and out with aluminium sheet. The services, furnishings and kitchen, including cooker and refrigerator, were all installed in the factory. The four sections were placed on modest foundations and were simply and quickly bolted together. The parents of Neil Kinnock, leader of the Labour Party in opposition to Prime Minister Margaret Thatcher in the 1980s, lived in an AIROH prefab. He remembered, ‘It had a ftted fridge, a kitchen table that folded into the wall and a bathroom. Family and friends came visiting to view the wonders. It seemed like living in a spaceship.’25 The AIROH prefabs proved to be durable and popular homes. In 1949, the pioneering metalworker Jean Prouve designed unitised aluminium curtain walling, with a module width of 1.45m and a weight of only 92kg, for the Federation Nationale du Bâtiment Ofces in Paris. When Brookes & Stacey designed unitised curtain walling for an ofce building in the City of London in 1989, this practice of full prefabrication was still seen as ground-breaking, although it has since become the norm for high-quality curtain walling projects on tight urban sites.

2.26 The kitchen of an AIROH home.

Although Manhattan in the 1950s was a key location of the development of aluminium curtain walling, this should be set in a wider context of the development of the use of aluminium in architecture. The aluminium curtain walling of the UN Secretariat Building is described as the frst curtain walling in New York, as it was installed before Lever House, designed by Skidmore, Owings & Merrill (SOM). The site was cleared in 1947 and construction started in 1948; the UN Secretariat Building was completed in 1950, and the complete facility opened in 1952. The Advisory Board of architects for the UN Secretariat Building consisted of ND Bassov (Soviet Union), Gaston Brunfaut (Belgium), Ernest Cormier (Canada), Le Corbusier (France), Liang Seu-Cheng (China), Sven Markelius (Sweden), Oscar Niemeyer (Brazil), Howard Robertson (UK), GA Soilleux (Australia) and Julio Vilamajó (Uruguay), with Harrison & Abramovitz acting as executive architects. This team produced a series of designs from which Le Corbusier’s and Oscar Niemeyer’s design proposals were

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2.27 UN Secretariat Building, New York, executive architects Harrison & Abramovitz, 1950, photographed in 2013.

merged together to create a hybrid project named 42G. The UN Secretariat Building was refurbished between 2007 and 2012, including full replacement of the curtain walling, which retains the original appearance yet is much more energy efcient. Metal was mutable, purposeful and poetic in the hands and imagination of Jean Prouve. Much remains to be learnt from this pioneer of the use of aluminium to assemble architecture. Pavilions are test beds for ideas for future architecture and new (or newer) technologies and techniques, which often cross over into mainstream contemporary architecture and infrastructure in a very short timescale. Jean Prouve’s Aluminium Centenary Pavilion was built in 1954 on the south bank of the River Seine at Quai d’Orsay in Paris, to celebrate the 100th anniversary of the industrial production of aluminium in France.26 This pavilion combines cast, pressed and press-braked aluminium components, forming both structure and cladding. 38

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2.28 The Aluminium Centenary Pavilion, designed, fabricated and assembled by Jean Prouvé in 1954, was relocated to Villepinte, Paris, in 2000.

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2.29 The gasketed aluminium curtain walling grid of the General Motors Styling Administration Building, by Eero Saarinen, 1955, with the aluminium-clad dome of the Styling Auditorium in the background, also by Eero Saarinen.

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The General Motors Technical Center, in Warren, Michigan, was designed by Eero Saarinen as a campus of three-storey buildings arranged around the fve staf groupings of the company: research, engineering, process development, styling and service. Saarinen believed that architecture should be expressive of its time and technology. Based on technology developed by General Motors, the Technical Center is clad in the world’s frst gasketed curtain walling on extruded aluminium mullions and based on a 5ft module (1.524m). Polychloroprene (trade name neoprene) had been invented in the 1930s by DuPont. The frst well-documented

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installation of neoprene gaskets was the assembly of the Harrisburg West Interchange Turnpike Booths in Pennsylvania, in 1949. In 1985, Alan Brookes noted, ‘The gaskets on this project are still providing sound weathering and structural retention.’27 The frst block of the Technical Center, the Dynamometer Building, constructed in 1951, soon leaked as the sealant caulking failed to adhere to either the aluminium framing or the panelling, which was glass and vitreous enamel. General Motors, based on its experience with gaskets in the automobile industry, applied its resources to solving the problem and produced a weather seal similar to that used on the Harrisburg Turnpike Booths.28 This zipper-type gasket allowed the glass to be accurately positioned within the aluminium framing before pressure was applied via the gasket. The gaskets appear to have been butted and glued; vulcanised corners were a later development. These gaskets were not continuously stretched around a curved corner, as in a car windscreen. In total, 4,600m of neoprene gaskets were installed at the Technical Center. Saarinen’s goal was ‘an architecture of precision’ to honour the vehicles mass produced by General Motors.29 The dome of the Styling Auditorium, completed in 1955, is formed from 9.5mm steel-plate shell, which is a semi-monocoque (see Chapter 1), as there are internal stifening angles. Saarinen protected the steel dome with 25mm-thick rigid insulation. It is fnished with 2mm-thick aluminium shingles, which minimise rainwater penetration, like rainscreen cladding. The insulation is protected from any water ingress by a waterproof membrane below the aluminium cladding. Galvanic corrosion (or bimetallic corrosion) between the steel structure and aluminium cladding is prevented by the use of neoprene washers, ensuring that the two reactive metals, which have a galvanic potential, never come into direct contact.30 The Alcoa Building is a 30-storey ofce tower in downtown Pittsburgh, Pennsylvania, designed for Alcoa by architects Harrison & Abramovitz and opened in 1953. Popular Mechanics described it as ‘the world’s frst aluminum skyscraper’ in December 1953.31 It is clad in unitised pressed aluminium curtain walling, measuring 1.829m by 3.658m, which was pre-glazed.32 The curved corner aluminium windows rotate for internal cleaning and are sealed by an infatable gasket. Aluminium was also used extensively in the construction of these ofces, from aluminium air-handling ducts to plaster lathes. The curtain walling was the subject of extensive prototypes and full-scale mocks-ups by Alcoa in collaboration with Wallace K Harrison and Max Abramovitz. Alcoa considered the building to be a ‘30-storey demonstration of aluminium’s usefulness, economy and beauty… showing aluminium to be at once practical and economical in almost every phase of building construction’.33 The curtain walling, as well as being unitised, is detailed with bafed open joints, anticipating the development of rainscreen panels in the 1960s.34 Inspected in the summer of 2013, this project was described as being in remarkably good condition.35 During 2015–16 it was converted to mixed use, including retail, ofces and apartments. 41

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2.30 The Alcoa Building, Pittsburgh, Pennsylvania, by Harrison & Abramovitz, 1953, ‘the world’s frst aluminum skyscraper’.

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2.31 (above left) Drawing of the unitised aluminium curtain walling of the Alcoa Building.

2.32 (above right) The frst unitised curtain walling panel being installed on the Alcoa Building. The panels are secured to fanged fttings bolted to freproofed steel beams.

2.33 Internal details of the Adlake aluminium windows of the Alcoa Building, which were fabricated by Adams & Westlake, who also manufactured aluminium railway coaches.

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2.34 Slender aluminium curtain walling on the Manufacturers Hanover Trust Company Bank, 510 Fifth Avenue, New York, by Skidmore, Owings & Merrill, 1954.

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Manufacturers Hanover Trust Company Bank is a modest four-storey bank on New York’s Fifth Avenue (No. 510). It was designed by SOM and completed in 1954. The design demonstrates a clear structural logic and precise detailing, which ofers transparency by both day and night. Apparently, the client, Manufacturers Hanover Trust Company, wanted to create a prestige bank without lettable foors above – under the New York zoning laws, this building could have been much taller. The aluminium curtain walling is a bespoke assembly of open sections, which was still crisp in appearance when inspected and photographed in 2013 (by this time, the former bank had become a fashion store).36

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The Reynolds Metals Company ofce, located fve miles north of central Richmond, Virginia, was designed by SOM as an elegantly detailed three-storey building, and completed in 1958. One of the design aims was to showcase the company’s expertise in the production of aluminium components. The particular signifcance of this building in the history of architecture in the 20th century lies in the design and specifcation of vertical and adjustable solar control louvres for the east and west façades in an era when many architectural historians suggest solar control was ignored. The louvres are made up of two matching open aluminium extrusions fxed to an aluminium extruded box section, forming a tapered louvre in cross section. SOM’s confdence in designing with aluminium was clearly growing with their consistent use of the material during the 1950s.

2.35 (left) 510 Fifth Avenue, New York, photographed in 2013.

2.36 (right) Internal view of the aluminium curtain wall of 510 Fifth Avenue, photographed in 2013.

The following year, in 1959, Minoru Yamasaki’s design for the Reynolds Metals Regional Sales Ofce in Southfeld, Michigan, was completed with a fligree solar shading veil of aluminium. This project would not look out of place in a contemporary architectural magazine because of its crisp and elegant detailing. 45

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2.37 Reynolds Metals Company ofce, Richmond, Virginia, by Skidmore, Owings & Merrill, 1958. View of the inner courtyard.

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2.38 Detail of the encircling canopy with adjustable aluminium sun louvres of Reynolds Metals Company ofce, Richmond, Virginia.

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2.39 Filigree aluminium solar shading of the Reynolds Metals Regional Sales Ofce, Southfeld, Michigan, by Minoru Yamasaki, 1959.

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2.40 Entrance level of the Reynolds Metals Regional Sales Ofce, Southfeld, Michigan.

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The former World Headquarters of the Pepsi-Cola Company is located on a corner block at 500 Park Avenue, New York. This crisply detailed 11-storey ofce was completed in 1959. SOM used a recessed service tower, clad in black granite, to separate this ofce from its neighbour. The street façade has an articulated aluminium curtain walling, which creates an elegant and transparent yet modest ofce tower. The spandrel panels are 6.35mm-thick (¼ inch) anodised aluminium and the external I-beams are polished aluminium extrusions. The grey-green glass panes are single sheets of 13mm (½ inch) polished plate glass measuring 2.743m high by 3.962m wide. The curtain walling is an assembly of open extruded aluminium sections with the primary architectural expression being generated by the external aluminium I-beam mullions. Gordon Bunshaft was the design partner working with project architect Natalie de Blois and her team within SOM. The World Headquarters is described in the Landmarks Preservation Commission listing as an ‘understated monument to corporate America’.37 2.41 The World Headquarters of the Pepsi-Cola Company, 500 Park Avenue, New York, by Skidmore, Owings & Merrill, 1959.

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2.42 500 Park Avenue is currently occupied by ABNAmro Bank, photographed in 2013 across this busy Manhattan street

2.43 Bespoke aluminium curtain walling mullion of the World Headquarters of the Pepsi-Cola Company.

2.44 External details of the articulated aluminium curtain walling of 500 Park Avenue, photographed in 2013.

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The Climatron is a 53m-diameter geodesic dome designed by Buckminster Fuller with architect Murphy and Mackey and completed in 1960. This dome, in St Louis, Missouri, houses a conservatory with a range of climatic conditions, from tropical rainforests to dry tropical and oceanic climates. The external structure of aluminium tubes and aluminium rods was sealed by an acrylic skin, which is held in place by neoprene gaskets. Between 1988 and 1990, the Climatron was refurbished, including the replacement of the acrylic skin with 2,425 panes of heat-strengthened laminated glass with an inner low-emissivity coating, which helps to retain solar energy, thus reducing heating costs.

2.45 The Climatron, St Louis, Missouri, by Richard Buckminster Fuller, 1960.

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The Metalka Building in Ljubljana, Slovenia, was designed by architect Edo Mihevc and completed in 1963. It was the frst high-rise ofce building in the city. Metalka is an import/ export frm dealing with metal products, including aluminium sheets, castings and extrusions produced by IMPOL. Boeing is one of its customers. Metalka’s intention was that the ofce building should express its business and showcase the use of modern materials, especially aluminium. Mihevc used the Seagram Building in New York, designed by Ludwig Mies van der Rohe and completed in 1958, as an inspiration for the new building in Ljubljana, especially its urban massing of a high-rise tower set back from the street and fronted by a public square. The façade, however, is based on the Alcoa Building in Pittsburgh, designed by Harrison & Abramovitz. The façade was designed and developed by Branko Kraševac in 1960 and 1961. It is assembled from aluminium curtain walling with pressed aluminium sheets, where the form provides rigidity. The aluminium panels are silver anodised with a little golden refectivity. By the 1960s, aluminium and its alloys had become an everyday material, contributing to a mixed-material built environment.

2.46 The Metalka Building, Ljubljana, by Edo Mihevc, with façade design by Branko Kraševac, 1963.

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3.1 A 7-tonne coil of hotrolled aluminium sheet at Norsk Hydro.

CHAPTER 3

Flexible When a metal component is being intelligently designed many factors are taken into account: the cost of the fnished article, its strength, reliability in service and appearance. Often the facilities and skills of the manufacturer cause one or other process to be selected. WILLIAM ALE X ANDER AND ARTHUR STREET1

Design and Fabrication Processes The primary reason for the widespread adoption of aluminium for the components of human life – from Apple laptops to curtain walling – is its inherent fexibility, not necessarily its physical fexibility. In some applications its stifness, provided by a high strength-to-weight ratio, is of vital importance. In many applications it is the fexibility of designing with aluminium that is key. Aluminium extrusions can adopt complex forms without additional costs, details can be built in that facilitate the fabrication process – such as a screw groove that ensures fxings remain correctly placed or screw ports that enable aluminium sections to be fxed together. Aluminium can be cast, extruded, roll formed, press moulded and spun. It can be readily drilled, machined, laser cut, waterjet cut and bonded or welded. It accepts fnishes well, ofering long-term durability, as set out in the next chapter. Extraction Aluminium Building / Infrastructure In Use

Smelting

Recyclable

Recycling Further Recycling Cast / Extrusion & Rolling Finishes Fabrication / System Architectural Design Maintenance

3.2 All participants in the aluminium industry add value: including the owners and managers of architecture and infrastructure, key stakeholders of sustainability – via inspections and maintenance during the in-use phase.

Inÿnitely Recyclable

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Forming Sheet Aluminium Although metals have a crystalline structure, the bonds between crystals and crystalline layers are relatively weak. Metals are therefore mutable and thus forgeable and formable. The starting point for forming sheet aluminium is a cast slab ingot of a chosen alloy. This is machined to remove surface roughness resulting from the cooling of the aluminium during vertical casting and then heated to about 360°C. It is then hot rolled to create a homogenous metallic structure. This slab, about 300mm thick, is fed into a rolling mill that in its most basic form is two high-precision steel rollers, known as work rollers. The rollers reduce the aluminium to a specifed thickness; typically, this is the frst stage in achieving a fnal specifed gauge for the sheet or foil. A number of passes through the rolls may be required, or a second-stage mill will be used. Although mills are now computer numeric controlled (CNC) with specifcation parameters displayed in real-time during the process, the metal structure undergoes quantum efects, and the craft skills of the operatives remain of vital importance in achieving the specifed product. The hot rolling and cold rolling are two stages of a common process, where a 7-tonne slab, about 6,000mm by 300mm, will become a coil 3mm thick and 1,500m long, or at 0.2mm thick (the gauge for, say, a food carton), the coil will be about 40km long. Cold rolling is undertaken at a temperature low enough for strain hardening to occur; typically, a hot-rolled coil is allowed to cool to ambient temperature before cold rolling.

Forming Sheet Metal Components All the processes for forming sheet metal are dependent on the ductility of the chosen metal or its alloy. If a metal is pre-fnished with a polymeric coating, for example, the capability of the fnish to withstand the forming process also needs to be considered. There are fve basic methods of forming sheet metal into components: • hand forming • roll forming • press braking • spinning • pressing or stamping. Hand forming components from sheet metal involves stretching the metal by striking it with a hammer or mallet. The 1948 prototype aluminium body panels of the Jaguar XK120 sports car were hand formed. Pressing or stamping involves two steel formers (top and bottom) and considerable mechanical pressure. An example is shown in Chapter Four – the pressed aluminium cladding panels of Herman Miller Distribution Centre, Chippenham. The other three methods of forming sheet metal components are discussed below.

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Roll Forming Profled sheet cladding or roofng are very familiar linear building components. However, the process and its constraints remain unfamiliar to many architects. Most roll formers purchase the sheet metal in coil or pre-cut blanks. This may be mill fnish, embossed or coil-coated aluminium. Roll forming is applicable to a wide range of metals of appropriate hardness, including steel and copper. The aim of roll forming is to produce a rigid component from a thin sheet metal by developing a cross section of sufcient depth for the required span. The profle is formed by the progressive development of the shape by roll-forming tools (see Figure 3.3). It is essential that the fnal form is developed progressively in stages. A tool to develop an apparently simple square edge will have eight stages. If a desired form is produced in too few stages, too abruptly, the form will lack precision. The multiple stages minimise the risk of faring, where the sheet, say a panel skin, will be wider at the two ends than the middle. This is the result of tension being released at the end of the profle. If a sheet is not fed through square to the tool, residual stress will result in the sheet not being fat, which is unacceptable in the face of a cladding panel, for example. This is known as crabbing.

3.3 Roll forming the edges of a metal sheet to form the face of a metal composite panel.

One constraint on roll-formed sheet components is the availability and size of sheet material. The constraint is primarily the width; the typical maximum is 1.25m, depending on the metal substrate and additional process required, although a 1.5m-wide sheet is available in some metals. It is important to remember that the width of the fnal product is a result of the developed form. Essentially, any stretching of the metal is minor and can be negated; the width is a result of the surface length of the profle. Press Brake One way to avoid faring in forming a sheet component, such as a metal tray, is to use a press brake. The metal is formed by the action of the upper press tool into the bed or lower tool of the press. The pressure necessary is dependent on the gauge, or thickness, of the metal. As the force is applied as a uniformly distributed load over the length of the section, an even fold results, thus avoiding faring. For a square section, it is a one-stage process. One constraint of a press brake is the length of the press – typically 3 to 4m. Presses up to 12m can be found in Europe. It is possible to use two press brakes together with staggered tools. Sheet metal up to 10mm thick can be press braked, however the associated tolerances typically increase with thickness. Press brakes are inherently fexible, with interchangeable top and bottom tools. Tool selection is based on the angle and radius required in the pressing. The minimum radius at the corner of a 90° uncoated press-braked section is a function of the thickness of the metal, where internal radius equals the thickness of the metal. For a pre-coated metal, the radius should not exceed the stretchability of the coating (see Figure 3.5). When press braking aluminium, it is essential that the alloy and work hardening of the sheet are carefully controlled. If an inappropriate alloy is used, the fnal component will not be stif enough or stretch cracking and/or brittle failure will occur, thus a component will either not function correctly or will look unsightly, or premature failure will result. 57

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3.4 A–H The eight stages of forming two 90° returns on a metal sheet cladding ‘skin’ or panel face.

3.5 Recommended minimum radius for press braking a coilcoated metal – PVDF (polyvinyl fuoride coating).

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In designing a press-braked component, it is essential that there is sufcient room for the tool to be withdrawn. This has led to the development of swan-neck tools, which allow deep channel sections to be formed. If a narrow channel section is required, it may be necessary to make the vertical side asymmetrical in height, to enable the component to be removed from the tool (see Figure 3.6). It is possible to press brake smooth curved sections, as demonstrated by the press-braked and then anodised aluminium gutter of East Croydon Station, by Brookes Stacey Randall Fursdon, and produced by Majors of Croydon. The details of the restored roof of John Nash’s Royal Pavilion at Brighton (1815–22) used the same production method. The constructional aesthetic is governed by design and not the technology. In producing a smooth curve, it is essential that the section is pressed in small increments, otherwise telegraphed lines will show. This process can be aided by the use of a computer numeric controlled (CNC) press brake. The presence of telegraphed lines can also be a function of thickness. Curved column casings with folded fxing fanges are an example of

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components that can only be press braked, as it would be impossible to design a roll-forming tool through which such formed sheets could travel. Roll forming and press braking produce linear components. If a rotated geometry in metal is desired, or required, a spinning should be considered. Spinning Components produced by the spinning process are probably familiar to many readers in the form of aluminium light fttings. The spinning process starts with a fat sheet of the chosen metal, which is rotated at speed and formed over a hardwood or steel tool. It is also possible to form thin-walled rotated forms using spun castings. In many applications, aluminium is the frst-choice material to form spun components. 3.6 It is essential to design for removal from the press tool.

3.7 Aluminium spinnings on Selfridges Department Store, Birmingham, by Future Systems, 2003.

3.8 A laminated birch-ply spinning tool.

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Selfridges Department Store, in Birmingham, was designed by Future Systems and completed in 2003. The store has a steel frame and a sprayed-concrete building fabric that was then coated in 80mm of Sto insulated render. Each of the 15,000 aluminium spinnings is fxed back to the concrete by a single bolt, which is capable of carrying the weight of a person (to deal with unofcial climbers). The building fabric takes inspiration from and expresses the world of fashion within the store. The Sto render is fnished in Yves Klein blue and the aluminium spinnings were inspired by a dress designed by Paco Rabanne (c.1967–68), with linked-polished aluminium panels. The aluminium spinnings, 3mm thick and with a 660mm diameter, were organised by James and Taylor, specialists in façade engineering and procurement. The spinnings are silver anodised with 25µm, in accordance with BS 3987:1991. Deyan Sudjic believes that this project has become part of the identity of the city: ‘Selfridges’ discs have become shorthand for the store and thus a new Birmingham, busy trying to shrug of its bleak post-war image.’2 Selfridges was refurbished in 2021 because, after 17 years, leaks occurred. There was also a need to double the depth of insulation to 150mm of mineral wool. The anodised aluminium spinnings were all found to be in good condition and were stored before reinstalment.3 1

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Feature dome – 660 dia Support ring Quarter turn security fastener Outer sealing components Inner sealing components

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3.10 Selfridges façade prototypes: Future Systems also prototyped a bright-yellow ground colour.

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Superplastic Alloys The limitation of cold forming metals under pressure is their ductility and thus the dangers of either brittle failure or wrinkling. This can be overcome by the use of superplastic alloys, which are capable of elongation of up to 1,000%. This compares to an elongation of 30 to 40% for typical steel or aluminium alloys. Superplastic aluminium is now extensively used to form automotive, aerospace and architectural components. The superplastic quality of an alloy is the product of a fne and stabilised grain structure resulting in high ductility. Superplastic aluminium is appropriate when a doubly curved element or a component with a complex surface is required. The aim could be to create stifness in an otherwise fat component, such as a cladding panel, or to interface with the geometry of other components, such as in an aero-engine air intake. The range of superplastic aluminium alloys available includes: 100 and 150 (2004), Supral 5000 (5251), 5083S PF, 7475 SPF and 8090 SPF. Alloys are selected on the basis of required stifness and forming method. The four primary methods of superplastic forming are: • cavity forming – conventional and drape • diaphragm forming • bubble forming • back pressure forming.

3.11 A comparative elongation test of superplastic aluminium and other aluminium alloys.

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3.12 Indicative design guidance for superplastic aluminium.

The profled cladding panels of Sainsbury’s supermarket, Camden, London, by Nicholas Grimshaw & Partners, 1988, were produced by cavity forming. Designers should note that the thickness of the sheet reduces in the ‘deepest’ parts of the mould.4 Diaphragm forming is a relatively expensive process and has primarily found applications in the production of aerospace and defence components. However, the perforated acoustic ceiling panels in the subway of Stratford Jubilee Line Station, 1999, by WilkinsonEyre, were produced by diaphragm forming. 5 Overall size is dependent on tooling and available sheet. Taking an architectural example, Superform’s maximum size for a formed panel is 3,000mm by 2,000mm, with a depth of 600mm. Figure 3.12 gives indicative guidance on radii and aspect ratios for ribbed sections. It can be more economical to form a panel with a fat edge and clamp it into a pressure-plate curtain walling system, as at Gatwick North Piers, 1980, by YRM. 63

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The Sainsbury Centre for Visual Arts, at the University of Norwich, designed by Foster Associates (now Foster + Partners) and completed in 1978, was originally clad in an integrated system of aluminium panels, aluminium louvres and panels that were fully glazed, yet had the same aluminium edge detailing. The ribbed panels were formed using superplastic aluminium and fnished with natural anodising. These panels had to be replaced due to premature failure of the superplastic aluminium. The cause of the failure of the superplastic aluminium cladding has never been formally reported; however, it is understood to be the combination of two factors: excessive thinning at the hemispherical corners and the production of sulphuric acid, caused by water being in contact with the phenolic core, leading to corrosion of the 3.13 The Sainsbury Centre for Visual Arts, original panel detail by Foster Associates, with ladder gasket and superplastic aluminium panels.

3.14 Superplastic aluminium cladding and glazing of the Sainsbury Centre for Visual Arts, by Foster Associates.

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aluminium. Too often building ‘failures’ are buried in insurance settlements. It should be noted that the Sainsbury Centre, which was completed in 1978, was a very innovative application of superplastic aluminium.6 Cost savings can be achieved in comparison with fabricated or assembled parts by using superplastic aluminium. A single superplastic component will ofer weight savings, and structural and visual continuity. When formed in aluminium, the component retains all the advantages of ‘conventional’ aluminium alloys, including the range of fnishes and a good strength-to-weight ratio. In comparison to die-casting, the tooling costs are signifcantly lower. Superplastic components have the beneft of ofering form and grain to a product or building. An alternative method for forming aluminium cladding panels is explosion forming, as undertaken by 3D-Metal Forming BV of the Netherlands, which was founded as a spin-of company from TNO (the Netherlands Organisation for Applied Scientifc Research) in 1998.7

Milling, Machining and Cutting The bedrock of aluminium fabrication processes is milling, machining and cutting. Most aluminium alloys are relatively soft and this aids all of these processes, especially in comparison to mild and stainless steels. Apart from the use of computer numeric control (CNC) systems, these processes would be familiar to the workers in a 19th-century workshop. The general practice is for the system houses to sell the CNC control cutting centre as well as the curtain walling and window systems. Interestingly, Schüco places a strong emphasis on improving the workfow and certainty of fabrication processes for its clients, the fabricators. This is embodied in fabrication data centres that bring the building information modelling (BIM) and all of Schüco’s systems, also in 3D, into the fabricator’s workshop in the form of a robust touch screen.

3.15 A CNC machining centre cutting a circular port in a square extruded aluminium section at Unterfurtner, during the fabrication of Vague Formation, a mobile music pavilion, by soma, 2011.

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Laser Cutting A laser is computer numeric controlled (CNC) to cut sheet materials. Laser cutters come in three types: moving material, fying optics and hybrid systems. In the frst type, as the name suggests, the laser optics are fxed and the material moves (with the supporting bed). In the second type, the table is stationary, and the cutting head moves – hence fying optics. This technique includes fve-axis machines, thus sophisticated angled cutting is practical. In hybrid laser cutting, the bed moves in one direction, say the X-axis, and the cutting head along the Y-axis. Laser processing of materials is a well-developed technology. Peter Houldcroft (Deputy Director of The Welding Institute) is credited as the frst person to use laser cutting to cut metal, when in 1967 he cut 1mm-thick steel sheet with an oxygen-assisted focused CO2 laser beam.8 The frst laser was produced in the USA by Ted Maiman in 1960.9 Typically, aluminium sheet up to 8mm thick can be cut by a laser, with aluminium alloys more readily cut than pure aluminium. AGA advises that ‘anodised aluminium is easier to cut due to the enhanced laser light absorption in the thick surface layer of aluminium oxide’.10 Philip Beesley, a pioneer of digital fabrication since 2003, has produced immersive installations, primarily from fat stock materials. He took one process, laser cutting, and initially two materials, acrylic and Mylar, and produced an inventive and immersive three-dimensional installation. He used minimal materials with the minimum of waste via carefully considered packing geometry.11 In 2012, working in collaboration with the author, Dr Chantelle Niblock and their students, Philip Beesley designed the Protocell Mesh. For the frst time he used laser-cut aluminium components to form the hyperbolic grid shell of this installation.

3.16 MARS students assembling the Protocell lilies in Nottingham.12

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Philip Beesley takes inspiration from Richard Buckminster Fuller, yet the geometry is more organic. Protocell Mesh was part of the Living Architecture research programme. It was the key installation in the ‘Prototyping Architecture Exhibition’ 2012–13, organised by the author and exhibited in Nottingham and London, England, and Cambridge, Ontario, Canada.13

3.17 Protocell Mesh, designed by Philip Beesley, frst assembled in Nottingham in 2012 for the ‘Prototyping Architecture Exhibition’.

The umbrella stays for Protocell Mesh were fabricated from 3.2mm-thick aluminium and the chevrons from 1.6mm-thick aluminium. Both were laser cut from 3003-H14 aluminium alloy and left mill fnish. These components proved somewhat challenging to one’s fngers, as they were assembled by hand. The temper also proved to be too ductile during disassembly, which occurred three times (in Nottingham, London and Cambridge, Ontario). A higher, stifer temper would make a better specifcation in future. Waterjet Cutting To cut metals with a waterjet cutter, it is necessary to add abrasives to the pressurised water. The mixture of water and abrasives is typically delivered through a nozzle at 40 million pascals. In common with all digital fabrication technology, waterjet cutters are computer numeric controlled (CNC). The bed of a waterjet cutter is a protective sacrifcial matt. The cutting process does not heat the aluminium being cut; however, the process is very noisy. Five-axis waterjet cutting is capable of producing three-dimensional components from sheet aluminium of an appropriate gauge. The waterjet-cut aluminium components of the Everyman Theatre and the Hive are discussed in Chapters 6 and 7, respectively. 67

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Welding Aluminium should no longer be considered difcult to weld. The skin and structure of the Networker 465 commuter train (1991) is formed from welded sheet aluminium to form a smooth outer profle and a monocoque construction. Contemporary examples of welded aluminium bridges are discussed in Chapter 5. The TIG (Tungsten Inert Gas) welding process was invented in the 1940s. In this process, an arc is struck between a non-combustible tungsten electrode and the work piece, with fller rod being fed independently. 3.18 Welding of the extruded aluminium structure for the Vague Formation, a mobile music pavilion, by soma, 2011.

3.19 Fillet and butt welds.

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Fluxes are unnecessary and oxidisation is prevented by a shield of inert gas, such as argon, that envelopes the weld area. In MIG (Metal Inert Gas) welding, a direct current of reverse polarity is struck between the work piece and a continuously fed welding rod, which acts as fller and electrode. Penetration of the work piece cannot be as closely controlled as in TIG welding. Welding of aluminium is now commonly used as a means of joining sections and can be successfully carried out on site, although the controlled conditions of a factory are often preferable to achieve good quality control. Where fnishing is critical, the specifcation of the fller metal and the process of welding should be adjusted to accommodate the fnishing method. Great care should be taken in the use of welding of components that are going to be anodised. The fller metal used for welding should match the alloy of the parent metal and the component should not contain silicon, if it is to be anodised. Friction Stir Welding Friction stir welding (FSW) was invented in December 1991 at The Welding Institute (TWI), with Wayne M Thomas named in the UK patent.14 It is typically used for joining aluminium extrusion and sheets. FSW is a solid-state joining process, where the metal is not melted; rather it is softened by a friction-induced increase in temperature and joined by mechanical pressure. FSW is, in essence, quite simple, although a brief consideration of the process reveals many subtleties. The principal features are shown in Figure 3.20. A rotating tool is pressed against the surface of two abutting or overlapping plates. The side of the weld where the rotating tool moves in the same direction as the traversing direction is commonly known as the ‘advancing side’; the other side, where tool rotation opposes the traversing direction, is known as the ‘retreating side’.15 London Underground S-stock trains, frst introduced in 2010, use large-scale aluminium components that are FSW. Touchdown start

Stop withdraw Start Tool shoulder

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3.20 The principal processes in friction stir welding, courtesy of TWI.

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3.21 Friction stir welding at Bayards: the bottom tray of the Large Hadron Collider.

TWI has continued to research and develop FSW. WM Thomas advises: ‘Bobbin stir welding is diferent from conventional FSW in that there is no need of an anvil support plate. The constraint and support necessary of the bobbin weld region is provided by near and far side shoulders of the tool. Friction stir welding using a self-reacting bobbin tool has been shown to be efective for joining hollow extrusions and lap joints.’16 He notes that primary advantages of bobbin stir welding will ‘eliminate partial penetration, lack of penetration or root defects’.17 Current applications of FSW include the welding of extruded aluminium bridge deck sections, as discussed in Chapter 5.

Additive Manufacturing In 1988, stereolithography and the stl 3D digital fle format was introduced. Initially the 3D printers were based on polymers and mineral powders, with the printers layering up the geometry topographically.18 By the middle of the frst decade of the 21st century, these and related techniques, such as multi-jet wax printing, were widely adopted by pioneering architects and engineers as a method of 3D representation, modelling and rapid prototyping.19 Multi-jet wax printing can be used as a stage in a casting process, such as the aluminium cast solar shading of Nasher Sculpture Center, in Dallas, Texas, by Renzo Piano Building Workshop and engineers Arup.20 In the second decade of the 21st century, it became possible to directly print metal parts and components. The process, known as additive manufacturing (AM), is the direct fabrication of end-use products and components employing technologies that deposit 70

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3.22 Plan drawing of a Nematox II node.

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metals layer-by-layer. It enables the manufacture of geometrically complex, low-to-mediumvolume production of components in a range of materials, with little, if any, fxed tooling or manual intervention beyond the initial product design.21 Renishaw produces metal powder bed fusion AM, using four lasers to digitally print fully functional components in tungsten and aluminium. Many consider that AM is primarily applicable to medical, aerospace and automotive applications. However, Nematox II is a digitally printed aluminium node for curtain walling, which was researched and developed by Holger Strauss of Hochschule Ostwestfalen-Lippe, Detmold, in collaboration with Kawneer-Alcoa. It is an example where there is no technological time lag between aerospace/automotive industries and architecture.22 The context for the development of Nematox II is the technological progression of building envelopes in the 20th and early 21st century. Nematox II seeks to address the geometric complexity of many contemporary façades by digitally printing an integrated node. AM ofers a path to seamlessly integrate this complexity into a directly printed aluminium component. Digital planning and digital fabrication ease the difcult details in fabrication and during assembly on site, requiring simple 90° cutting of extrusions, providing geometric precision. AM is not on a technology transfer wish list, it is available as part of the repertoire of the contemporary construction industry.

3.23 AM (additive manufacturing) digital printing in aluminium delivers the geometrical complexity of the Nematox II nodes.

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Aluminium Extrusions The aluminium extrusion process enables architects, engineers and designers to produce sections made to their exact requirements, at a surprisingly low cost. It is also a very direct process, allowing close control over the quality of the product, and is a very accessible means of production. There are four distinct routes whereby aluminium extrusions can become part of a building: • as part of a system, for example curtain walling • from stockholders’ stock lengths, for example standard sections such as T-bars, round tube, Zs and box sections (dimensions are often still in imperial!) • from extruders’ stock dies, for example mouldings, fashings, trims and edgings • from specially designed custom dies, for example for bespoke sections for a particular design. Proprietary systems: Most manufacturers would consider altering their system for special projects, but only where the installed value of the (sub)contract is substantial, that is, say, over £500,000. The key is the weight of aluminium required and the complexity of the new section. In some nations, it is also possible to get government grant aid for the cutting of new dies as part of a product or project research and development process. Bosch Rexroth ofers a range of aluminium extrusions as a structural system of components typically used to create laboratory assemblies and mass production lines. In 2006, KieranTimberlake used a standard Bosch Rexroth extruded aluminium frame to assemble the Loblolly House in Maryland.23 Stock lengths: One disadvantage of using stock items is that there is a limited range of sections and a traditional dependence on existing imperial dimensions. This often makes them incompatible with close-tolerance metric assembly. Stock dies: All extruders will produce aluminium sections from their range of stock dies, which are the copyright of the extruder, not its customer. Although a wider range of sections is obtainable than from stockholders, the only real advantage of stock dies over customdesigned dies is that the die exists. This therefore eliminates the drawing approval period, die cutting and associated costs, thus reducing the time from the order to the availability of the section. Custom dies: There are many companies, in most regions of the world, that can provide aluminium extrusions to customers’ orders. Companies such as Constellium, Kaye, Hydro or Nedal will provide bespoke extrusions to order. A typical timescale is six weeks to approve the sample extrusion, and a further four weeks for production. The steel dies required to extrude a given shape are relatively inexpensive, the cost being related to the size and complexity of the section (see below).

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3.24 Loblolly House, Maryland, by KieranTimberlake, 2006.

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3.25 Loblolly House was assembled using a standard Bosch Rexroth extruded aluminium frame, which is exposed internally. It was assembled by Bensonwood Homes, specialists in offsite fabrication of housing.

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3.26 Loblolly House is a beautiful and bourgeois home – a poetic demonstration of refexive technology providing comfort and wellbeing.

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3.27 A die maker from WEFA installing a porthole die for extruding a hollow aluminium section.

The combination of fnite element analysis with computer aided design and computer aided manufacture in the 1980s led to reductions in extruded aluminium section weight without loss of strength.24 Leslie Parks observed in 1986, ‘Extensive use is made of the CAD/CAM approach to section design to save weight without penalising strength in extruded [aluminium] sections. Average percentage weight reductions achieved 1982–1985 by industry are: building sections 10.2, window sections 26.4, carpet edging 22.7 and greenhouses 33.9.’25 Extruders ofer a prompt service, producing die drawings including sectional strength characteristics, weight and surface area. This software is available for architects and engineers to use directly in the design process. Die maker WEFA, formerly part of Alusuisse, has worked with ETH in Zurich to develop fow-modelling software of the forging process of extruding aluminium. This has been further developed into a standardised design knowledge database that enables dies produced by WEFA to run frst time, efectively eliminating extrusion trials. Joachim Maier of WEFA observes, ‘To compete in the contemporary global aluminium market a die maker needs to be capable of extruding more complex sections, with high surface quality and better extrusion speed – balancing the competing factors, thus proving certainty to the extruders.’26 Extrusion process In the production of aluminium extrusions, cylindrical or elliptical billets of aluminium, typically weighing about 200kg, are frst heated to a temperature of around 500°C before being placed in a steel container and forced, while still in a hot plastic state, through a steel die by a hydraulic ram to form the extrusion. The shape of the resulting section is governed by the 76

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die and by the ram forces applied. By using preheated billets and an autoloader, the hydraulic press can produce a continuous extrusion, the force of the ram being sufcient to weld the front of the new billet to the rear of the old as they are forced through. The emerging section is air cooled and guided down a run-out table of rollers before being automatically cut into production lengths of up to 40m; this is governed by the length of the run-out table. A controlled stretch is then applied to each length to straighten it before being cut to order. The length may need to be oversize to allow for anodising or other fnishing processes. The process is rapid. A hydraulic press can extrude at rates in excess of 20m/min, depending upon the size and shape of the section. For heat-treatable alloys, the process is completed by a precipitation or ageing treatment, the extruded length being ‘baked’ in an oven at 175°C for fve to ffteen hours. 3.28 Diagram of an extrusion press.

3.29 Extruded aluminium tubular sections, before straightening, at Sapa Tibshelf, Derbyshire, England, 1973 (designed by Foster Associates).

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The size of an extrusion is dependent on the size and ram pressure of the press; predominately circular die chambers and cylindrical billets of aluminium are used. The size of the die is therefore determined by the circumscribing circle diameter (CCD), which is defned as the minimum diameter that can contain the extrusion. Hydraulic presses are described by their ram pressure and by the maximum size extrusion that can be produced. The maximum size extrusion section is therefore governed by the combination of the maximum ram pressure and the size of die the press can accommodate. The common size within the UK is 180mm press, which leads to a maximum size of 170mm to allow for the structural stability of the steel die. Extrusions up to 400mm CCD can be produced in the UK. Constellium (formerly known as Alusuisse), in Singen, developed a press with a wider slot, like a London Underground sign, which enables it to extrude sections up to 600mm in diameter or 800mm wide, but only 100mm high. This was frst developed for the foor pan of the German high-speed ICE train, in the 1990s. Often the constraint of the size of the die can be overcome by design, enabling a number of extrusions to form the overall component, as in bridge decks, for example. Although rare in architecture, very small extrusions (10mm) are produced by the indirect method, where the billet is held frm and the die is pressed into the softened aluminium. Extrusion presses are expensive pieces of capital equipment; however, the steel dies are relatively inexpensive. The relative economy of a new extrusion die means that to produce a purpose-made extrusion does not require a multimillion-pound R&D budget. The cost of a new die is dependent on size and complexity: a die for an extrusion without voids, which could ft within a diameter of 180mm, can cost £2,800 to £3,000. A hollow die of a similar size can cost £4,000–£5,000.27 The cost of the extruded section is related to the weight of aluminium used, measured in kilograms, and is infuenced by the complexities of the section, such as the number of enclosed voids. Secondary processes, for example rolling in high-performance pultruded polyamide thermal breaks, are available directly from the extruder but add to the sectional cost. 3.30 Aluminium porthole dies, or mandrel dies, manufactured by WEFA, for extruding hollow aluminium sections.

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The die cost of specially made extrusions, then, is rarely a signifcant proportion of extrusion cost where typical commercial quantities are ordered. The cost of extruded metal per kilogram is infuenced by dimensions and confguration of the section, metal thickness, alloy, speed it can be extruded, tolerance limits and required surface fnish. Extrusion costs per kilogram are lowest for solid shapes and highest for complex hollow shapes, so efort should be made to obtain the desired structural result with extrusions that are as simple as practicable. An extrusion with a semi-hollow or deep recess requires a tongue in the die, whereas a fully enclosed void requires a two-part die with a mandrel supported by a bridge or webs. Both types must be supported securely to enable the die to withstand the extrusion pressure. Such features add to the die cost and usually reduce extrusion speed. Often only a slight change in a shape converts it to a less expensive classifcation, yet without compromising its function or appearance. To obtain a good extrusion, the designer will beneft from observing certain principles and early dialogue with the extruder.

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Design features The extrusion process can enable specially designed shapes to be produced at relatively low cost. The designer has to observe certain principles to obtain a good extrusion cost efectively, remembering that details such as screw grooves can be designed in efectively at no extra cost. These are listed below. • Extrusion factor: The thinner the section, the greater the likelihood of distortion during extrusion. Check the ratio between the circumscribing circle diameter (CCD) and the section thickness. • Thickness uniformity: The metal thickness throughout the extrusion should be as uniform as possible. Where changes are required, for example to increase the strength of a section at a particular part of the extrusion, these changes should be as gradual as possible. • Symmetry: The section of the extrusion should be as symmetrical as possible to reduce the efect of the section twisting as it leaves the die, but like many rules, this is often broken at a cost. • Open to hollow: Open sections with open voids, such as a C-shape, are produced using a tongue or plug in the die. These are generally easier to extrude than sections with enclosed voids, which are produced using two-part dies comprising a mandrel, which is held in place by bridges or webs. • Corners: Corners should be curved where possible. A minimum radius of 0.5mm is commonly used, which is still visually crisp. Internal corners are governed by the need to produce a readily extruded section or the ft of mating components, such as internal jointing sections.

Initial design

Final design – where possible design out voids and sharp corners 1 1

4 3

Guidance on groove depth: 3:1 can be increased to 4:1 with increased radii on entry

• Grooves: Avoid deep narrow slots as much as possible. A good aspect ratio is 3:1, or 4:1 with radii on entry. • One section or two: It can be easier to design a component as two interlocking extruded sections rather than one single section. • Design in details: These include screw grooves, screw guides, snap ft and other details that provide process advantages in production and assembly. • Finish and tolerance: The designer needs to identify the critical faces of the extrusion. The tolerances laid down in BS EN 755 and BS EN 12020 provide permissible deviations on thickness, length, straightness, angular and sectional dimensions. There is general agreement within the industry that the size of die, area balance and section thickness afect the economics of an extrusion. The speed with which an extrusion can be produced will afect its price per kilogram. However, it is notable that in the past 25 years leading extruders have pushed the boundaries of the possible when the architects and engineers have good reason to be demanding, be this a heat sink assembly for a data bank or the H-Post extrusion for the freestanding option in Dieter Ram’s 606 Universal Shelving System.

Screw grooves and other details can be designed in to an aluminium extrusion at no extra cost

A snap-ft joint between two aluminium extrusions

3.31 Design guidance on aluminium extrusions.

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Die size The size of a die is determined by the circumscribing circle diameter (CCD), which is the minimum diameter of the circle within which the section of extrusion may be contained. In order to keep an unbroken structural ring around the die, the CCD is usually at least 40mm less than the internal diameter of the billet container and a minimum of 5mm from the edge of the die. Both die cost and minimum allowable wall thickness increase as the CCD increases.

3.32 Extruded aluminium heat sink, courtesy of Aluminium Shapes.

650 400

3.33A and B Maximum die sizes at Sapa (a) and Nedal (b).

250

200

300

400

25 MN 40 MN 55 MN

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Area balance As far as possible, the cross section of the extrusion should be distributed equally around the centre of the CCD. Metal fow is slower towards the outside of the die in any extrusion, so a more even fow of metal can be obtained by placing thicker parts of the section near the periphery. A well-balanced cross section aids extrusion because it reduces cross fow of metal on the billet side of the die, so the extrusion speed may be higher. Carefully designed unbalanced shapes, however, are usually readily extrudable, but at slower speeds and higher costs. Thickness of metal is probably one of the most important factors governing extrudability and is more complex than simply quoting a fraction of CCD, which is often used as a method of estimating thickness. Section thickness afects extrudability both by its actual and relative position in the die. Small positioning lugs are not considered as having a signifcant efect on thickness, but excessively thin details and thin ends of elements should be avoided. Thick-thin junctions are also to be avoided, but if required should be cornered by rounding or use of fllets. Even a 0.5mm radius improves the metal fow compared with a sharp corner. Compared with a cold-rolled or hot-rolled steel section, these radii are not perceptibly rounded.

3.34 Stair tread of Lloyd’s of London.

3.35 Stair tread detail section of Lloyd’s of London, designed by Richard Rogers Partnership, drawing dated 24 June 1983.

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However, as with all areas of human invention, guidance on the design of aluminium extrusions is only a starting point and extruders can produce sections which bend the rules or even redefne the possible. The stair tread of the Lloyd’s Building, 1986, is a perfect example. The general rule is to minimise or avoid the use of voids. This single extruded aluminium tread, produced by Nedal in the Netherlands, has multiple voids. Apparently, the inspiration for this design was John Young, of Richard Rogers Partnership, seeing a stack of rectangular extrusions in Joseph Gartners’ works in Germany. Still in service at Lloyd’s, the stair tread section can now also be seen in the Science Museum, London, as an exemplar of the use of the aluminium extrusion process. Tolerances In many cases, the close control of the tolerance of the aluminium extrusions is critical to the success of an application. The tolerances for aluminium extrusion are set out in a number of Euro Norms, including: BS EN 755, BS EN 12020 and BS EN 13957. Tolerances are given for cross-sectional dimensions, wall thickness, straightness, contour, convexity and concavity, twist, angularity and radii of corners. This is not an exhaustive list and direct reference to the standards is recommended; however, most extruders can achieve two-thirds of the tolerance levels given in the Euro Norms. East Croydon Station, designed by Brookes Stacey Randall Fursdon and completed in 1992, was designed to serve 14 million passengers a year and is southeast England’s busiest through station; in 2015 it served more than 20 million passengers. The glazing system is an example of a purpose-made extrusion used to produce a project-specifc assembly, although the overall contract of the new station was under £4.5 million. The structure spans onto the existing abutments at either side of the six railway tracks, creating a 55m clear space. This minimised disruption to the railway and created a column-free interior. Below the external masted steel structure is a highly glazed envelope, which provides a sophisticated shelter. The glazing system, specially developed by Brookes Stacey Randall Fursdon for this project, provides maximum transparency, yet is robust enough to meet the day-to-day demands of a railway station. The glazing system aims to maximise the potential of the toughened glass and the extruded aluminium supporting structure. Each pane of clear toughened glass is only supported at four points. The aluminium extrusion supports the glazing assembly and primarily resists wind loads via stainless-steel cast arms that reach 300mm into the 3m width of the glass pane, thus reducing the efective span to 2.4m and accessing a benefcial hogging moment. Thus defection of the glass is limited to span over 112. The form of the extrusion is elliptical to achieve an elegant and rigid structural form with minimum profle. The use of stainless-steel castings at the head end of the base transforms the essentially linear extrusion into a threedimensional building component. The East Croydon glazing system was tested at Taywood Engineering to BS 5368, parts 1–3 (EN 42, 86 and 77). 82

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3.36 Entrance to East Croydon Station, by Brookes Stacey Randall Fursdon, 1992.

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3.37 The glazing system of East Croydon Station, designed by the author, was tested at Taywood Engineering to BS 5368, parts 1–3.

The extrusion was also designed with front and rear grooves; it is a symmetrical and well-balanced section. The front groove is used to receive extruded silicone gaskets, acting as closure pieces at wall junctions, and the groove to the rear of the extrusion has been designed to carry door tracks, signage and receive internal glazing, as shown in Figure 3.38b. This economical solution is fexible and provides a visual alternative to the standard curtain walling box profle. The author chose to fnish the mast sections with silver anodising to retain the inherent metal aesthetic of the aluminium, with the beneft of anodising, which is a very hard fused oxide layer. However, care should be taken in its use and the following issues considered. • Ensure that everyone knows which are the signifcant surfaces – to avoid jig marks. • Suitable protection in transit is essential. • Protection on site from mechanical damage and mortar is also essential. The mortar or concrete will cause the anodising to go permanently ‘milky’ as a result of an alkaline reaction, which is impossible to reverse. • The location of the mandrel bridges in extrusions with voids should be agreed, as the chemical structure of the aluminium varies as it resolidifes after the mandrel. This can form a crystalline or dichroic structure, which has a diferent refectance to the section generally, thus modifying the appearance of the anodising in this zone. • The acceptable level of die marks should be agreed at the outset and checked on the trial run. 84

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3.38A–C East Croydon Station mullion: author’s initial sketch (a), Brookes Stacey Randall Fursdon’s tender drawing (b) and MAG’s (Modern Art Glass’s) inspected shop drawing (c).

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3.39 Dieter Rams’ 1955 sketch of a Braun Showroom.

3.40 The 606 Universal Shelving System, designed by Dieter Rams for Vitsœ + Zapf in 1960.

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Dieter Rams is famous for being Head of Design at Braun, 1961–95; however, he has also designed furniture for Vitsœ + Zapf. Rams designed the 606 Universal Shelving System in 1960. It is a universal system as all the details are fully reversible and the shelves can be reconfgured and extended with more components depending on the needs of the user, be this a homeowner, librarian or ofce worker. It was designed for ease of assembly and disassembly about 20 years before design for disassembly (DFD) had been coined.28 Vitsœ Managing Director Mark Adams sees ‘recycling as a defeat. That’s what you have to do if you fail to re-use.’29 At the core of the 606 Universal Shelving System today are four purpose-made aluminium extrusions: an E-track, an X-post, an H-post and a cross rail. Rams’ use of aluminium extrusions traces the developed of the extrusion process from open section in the 1950s to a multicellular extrusion H-post in 2012. Jonathan Ive considers Rams to be one of the most important designers of the 20th century: Rams’ ability to bring form to a product so that it clearly, concisely and immediately communicates its meaning is remarkable. The completeness of the relationship between shape and construction, materials and process, defnes his work and remains a conspicuously rare quality.30 Aluminium is fexible by design, fexible in manufacture and fnishing, yet provides components that meet high performance standards in terms of strength and stifness, while providing long-term durability.

3.41 (far left) The extruded aluminium x-post of the 606 Universal Shelving System, with an E-track attached.

3.42 (left) The extruded aluminium H-section of the 606 Universal Shelving System.

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4.1 Tin House on the Isle of Skye, by Rural Design, led by Alan Dickson and Gill Smith, 2016. The house is clad in millfnish profled aluminium sheets.

CHAPTER 4

Durability and Finishes The stewardship of buildings and infrastructure is a key component of long-term sustainability of the built environment. The durability of aluminium and its fnishes are two of the primary reasons it is specifed for architecture and infrastructure projects. Mill-fnish aluminium will rapidly develop a coating of aluminium oxide on exposure to air that forms a protective grey oxide coating on exposed aluminium components of about 4µm, which will patinate in time. It is a durable fnish in urban and rural locations. Tin House, by Rural Design, is set in the stunning landscape of the Isle of Skye and is wrapped in sinusoidal mill-fnish aluminium sheets. Sawmill Shelter, in the woodland of Hooke Park, was designed and built by students of the Architectural Association’s Design + Make MArch. The experimental tensile-timber canopy is weather-proofed by a mill-fnish aluminium skin.

4.2 Sawmill Shelter, Hooke Park, Dorset, designed and built by students of the Architectural Association’s Design + Make MArch, 2016.

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The durability of mill-fnish aluminium, exposed to the weather, is infuenced by a range of factors.1 The starting point for the consideration of aluminium and durability is the alloy itself; in simple terms: the purer the better. The introduction of other metals, such as copper to improve strength, will reduce the durability of the aluminium alloy. One option is a dual alloy with pure aluminium cold rolled, if it is a sheet material; the second option is to anodise or polyester powder coat (PPC) the aluminium.

4.3 The frst Kalzip aluminium standing-seam roof in Europe on the Nuremberg Congress Hall was installed in 1968. It has also been subject to long-term testing by the German Federal Institute for Materials Research and Testing (BAM).5

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The science of the atmospheric oxidation and corrosion of aluminium appears to be well understood, except the composition of electrolyte layers.2 Following initial oxidation and the formation of an ever-changing electrolyte layer, aluminium alloys progress to a stable state, when considered over a human timescale rather than a geological timeframe.3 The location of a site and microclimatic considerations need to be taken into account. The order of risk of corrosion (in ascending order) is rural, urban, industrial (highly polluted atmosphere), with coastal plus industrial being the worst case. However, there are examples of cast aluminium proving durable in highly polluted urban situations, for example the sculpture of Eros in London, or aluminium roof sheeting proving durable in a maritime/polluted context, for example Hamburg Docks. In Europe, since tighter pollution controls have come into efect, some consider the diference between rural, urban and industrial to have less signifcance in terms of corrosion.4 Clearly this is not the case in all regions of the world, especially where industry is not tightly regulated.

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Kalzip is an aluminium-sheet, standing-seam roof system that was invented in the USA and has become very successful in Europe as it ofers a very durable roof, formed of continuous sheets with no visible fxings or penetrations. The 21st-century applications of Kalzip are discussed in Chapter 7. The aluminium Kalzip roof of the Packing Hall of the Schumacherwerder Overseas Centre, in the Freeport of Hamburg, was installed in 1970. The hall is situated in the harbour area of the city, a marine environment where sodium chloride is the major atmospheric corrosive. This was one of three buildings tested by the German Federal Institute for Materials Research and Testing (BAM) to evaluate the durability and corrosion of aluminium. The tests showed that the diference between the inner and outer surfaces after nearly 40 years of exposure was 7µm (inner 47µm, outer 40µm). BAM stated in its report, ‘After 40 years’ exposure, the bulk material is not yet afected. At the present moment the function of the roof is completely in a good condition.’6

4.4 Graphs comparing the weathering of aluminium alloy NS3, in diverse climates and locations.

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4.5 The weathering of aluminium alloys (based on K Barton, Protection Against Atmospheric Corrosion: Theories and Methods, Wiley, 1976).

4.6 Holiday Inn Express, Nottingham: abseilers cleaning the aluminium cladding, 2012.

Aluminium is more durable when washed by rain and therefore architects and engineers should detail buildings, where possible, to facilitate the washing of the surface by rain. This contrasts with the traditions of masonry construction detailing. Aluminium components and systems should be detailed to avoid crevices, where water can be trapped and remain for long periods, either by open joint details such as a rainscreen cladding or sealing with a gasket or silicone seal. A logical extension of this is to wash periodically the aluminium sections, be this cladding or window extrusions. Guarantees of up to 40 years are available for super-durable polyester powder coating; however, such guarantees are dependent on periodic cleaning. Architects should design-in cleaning and maintenance access, even if this is not yet part of the legislative framework of the country they are working in. The need for regular cleaning does not appear to be well understood by building owners, but there is evidence that major facilities management frms have better understanding of the need for regular cleaning.

Microns Matter in Contemporary Architecture

4.7 Periodic cleaning is better than repainting, especially for fnishes on aluminium.

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The human eye is arrested by the surface of a building. In daylight the human eye can discern the texture of the building envelope, its colour, refectance and, in the case of aluminium panel, whether they are perforated, even from many, many metres away. The story of fnishes on aluminium is one of continuous and steady improvements over the past 40 years, based on long-term testing and improved processes and formulation. Finishing aluminium further enhances its durability, while retaining its inherent colour or providing an almost infnite range of colours. There are three main methods of fnishing aluminium components: anodising, polyester powder coating (PCC) and wet paint systems, including polyvinyl fuoride coatings (PVDF or PVF2).

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Anodising Anodising, or anodic oxidation, is an electrolytic process that deposits a chemically stable oxide layer on the surface of the aluminium. The resultant oxide flm is thicker and stronger than aluminium’s natural oxide covering. It is hard, porous, transparent and is an integral part of the metal surface so it will not peel or fake of. Once deposited, the oxide flm can then be coloured, electrolytically or with organic dyes, before it is sealed. All anodised surfaces have a satin matt appearance arising from the base aluminium, unless chemical brightening or mechanical pre-treatment has taken place. Anodising is suitable for extruded, cast, rolled, drawn and forged aluminium products. Note that cast aluminium components with high levels of silicone should not be anodised.7 Anodising for external application requires a flm thickness of 25 microns. As anodising is transparent, consideration of grain structure in sheet aluminium applications and dye quality and weld zones in extruded aluminium application are visually important. Anodising was frst used in architecture during the 1930s. Silver or natural anodising is a clear, transparent anodised flm, which shows the silver lustre of the underlying aluminium. It is achieved by omitting the colouring stage in the process sequence and going straight to sealing from anodising. Electrocolour anodising results in a range of colours, from light bronze to black. It is achieved by depositing cobalt or tin at the base of pores in the anodic flm. The colour is produced by absorption and refection of specifc light frequencies at an atomic level. For example, cobalt absorbs the blue element of the light falling on the surface, resulting in a bronze hue being refected. As the coloration is obtained through optical efects dependent on atomic particle size, it is totally fade-free. Interference anodising gives a spectrum of colours, of which the range of blue-greys are the most practical. It is the result of light interference caused by nickel in the base of enlarged pores in the anodic flm. Again, as the colour is the result of optical efects dependent on particle size, it is totally fade-free.8

Pre-Treatment

Rinsing

Etching (chemical milling) prepares the aluminium for anodising by chemically removing a thin layer of aluminium

Desmutting removes unwanted particles not removed by the etching process

Sealing

Colouring

Anodising

4.8 Key stages of the anodising process.

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4.9 Silver anodised perforated aluminium cladding of the Optic Cloak, Greenwich Peninsula, London, by artist Conrad Shawcross with Architect CF Møller Architects, 2016. In many weather conditions, this cladding has a glass-like appearance.

4.10 Optic Cloak: dawn to sunrise on 25 May 2017, photographed at fve-minute intervals.

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4.11 Anolok II™ dark-grey anodised elliptical extruded aluminium mast supporting the solar array of the Thames Water Tower, London, by Brookes Stacey Randall Fursdon, 1995.

Combination anodising provides a wide range of blues, reds, turquoises, greens and oranges, achieved by combining electrocolour bronze shades with lightfast organic dyes. Combination anodising is fade-resistant rather than totally fade-free. The hard oxide coating of anodising can reveal the grain structure of a rolled product, or the quality of a die and weld zones in extrusions with internal cavities. Anodising, introduced in the 1920s to protect aluminium aircraft components, is now a computer-controlled process, therefore colour should be sufciently consistent not to require maximum and minimum samples or range samples. Anodising is popular with many architects as it ofers the best possible durability, with a service life of over 80 years, and reveals the inherent quality of the aluminium components. If coloured anodising is specifed, a set of range samples should be agreed, especially if a dark colour is to be used; see, for example, the purple-blue anodising of Vertical Shell (see Figure 4.12). 95

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4.12 Vertical Shell, by artist Tobias Putrih with engineers Price & Myers, 2015, in the reception of the South Bank Tower, London.

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4.13 Specialist aluminium fnisher Barley Chalu’s computer-controlled anodising line, installed in 2016, is so tightly controlled that range samples may not be required for coloured anodising such as bronze.

Variation in colour is particularly noticeable in large uninterrupted expanses of fat panels, where even the grain of an aluminium sheet can become apparent. Foster + Partners specifed silver anodised aluminium for the cladding and curtain walling of the Commerzbank in Frankfurt. On this project, the architect avoided the potential pitfall of colour variation by the control of the alloy quality, which is critical, as is the orientation of the grain of the sheet aluminium, which is a rolled product. The plan form of this building and the articulation of the façades, combined with the careful placement of the anodised components, all helped to achieve a consistent appearance. This was achieved by close cooperation between the architects and the curtain-walling suppliers, Gartners. Anodising is a batch process and the maximum sizes of aluminium components that can be anodised are governed by the chemical bath sizes a particular anodiser has invested in. Applicator

Finish

Length (mm)

Width (mm)

Depth (mm)

Barley Chalu Barley Chalu United Anodisers

PPC Anodising Anodising

7,000 7,000 7,000

360 590 450

1,900 1,000 2,000

Table 4.1 Indicative maximum sizes from Barley Chalu and United Anodisers for polyester powder coating (PPC) and anodising.

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4.14 Silver anodised aluminium rainscreen cladding and curtain walling of the Commerzbank, Frankfurt, by Foster + Partners, 1997.

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Pre-Treatment Before Polyester Powder Coating Pre-treatment replaces the natural oxide flm of aluminium and can be a chemical process or an electrolytic process. Correct surface preparation of the metal is vital to ensure that the powder coating gives the full durability as expected by the coating manufacturer. Pre-treatment of aluminium involves a multistage aqueous process applied by either spray, rollers or immersion, which includes cleaning, surface etching and conversion coating of the metal.9 Chromate conversion coating is the simplest pre-treatment method. However, EU directive 2000/S3/EC recognised the environmental hazards of using heavy metals and required them to be phased out by 2017, although this has been delayed to September 2024.10 Applicators are progressively renewing technology and removing chromate-based pre-treatment processes. Alternatives include an automated, multistage immersion pre-treatment line using titanium/zirconium or fash anodising. Post chromate pre-treatments are as durable and date back to 1996.

Polyester Powder Coating Powder coatings are solvent-free paints applied to metals and other conductive surfaces. The coating is applied electrostatically and is cured under heat to allow fow and formation of a hard fnish that is tougher than conventional paint. Powder coatings yield less waste compared to liquid coatings and do not require a solvent to keep the binder and fller in a liquid suspension form. Polyester powder coating (PPC) is a two-stage process. Firstly, a manufacturer produces the powder; secondly, the powder is applied to the surface of the aluminium components. There are two types of powder coatings, thermosetting and thermoplastics (refecting the fundamental types of synthetic polyester plastics). Thermosetting coatings include a crosslinker in the formulation – when the powder is baked, it reacts with other chemical groups, increasing the molecular weight and improving performance properties. Thermoplastics do not undergo any additional reactions during the baking process, they simply melt to create the fnal powder coating.11 PLC controlled submersion systems (non-chrome)

Pre-Treatment

Chromating

Drying

Electrostatic Coating

Packing

Curing

4.15 The key stages of the powder coating process.

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4.16 Electrostatic application of polyester powder coating.

Today, powder can be produced without organic solvents; this ensures there is no volatile release of organic compounds (VOCs) into the atmosphere. The method of application allows the powder coating to be applied in one process. Excess powder is extracted, collected and reused; therefore the application process results in higher efciency, lower wastage and a lower economic cost.12 The production of polyester powder coatings involves the following stages: • The polymer granules are mixed with hardener, pigments and other powder ingredients. • The mixture is heated in an extruder. • The extruded mixture is rolled fat, cooled and broken into small chips. • The chips are milled to make a fne powder. The application of polyester powder coatings involves the following stages: • part preparation – the removal of oil, soil, lubrication greases, metal oxides and welding scales • pre-treatment • powder application • curing.

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4.17 A pre-treatment cleaning tank at Powdertech: pretreatment is critical to the durability of polyester powder coating.

4.18 A computer-controlled automated polyester powder coating line at Powdertech, which achieves very even coverage, combined with full recycling of unused powder.

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Long-term testing and quality control has been the key to the development of durable fnishes for aluminium. In 1986, Qualicoat was formed to raise the quality of coatings on aluminium on a global basis. It provides guidance and specifcations, as well as licensing applicators and monitoring processes. Powder manufacturers, including Axalta and AxoNobel, ofer coatings in a bold range of colours, typically designated by a RAL number,15 including metallic silvers and greys, and even soft coral pinks.16 4.19 Long-term exposure testing of polyester powder coatings in Florida, where insolation is high. Image courtesy of Qualicoat.

Table 4.2 Guarantees available for all classes of polyester powder coatings (PPC) in the UK. These guarantees are based on periodic cleaning, which depends on location.14

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PPC Class

Guarantee

Test exposure in Florida

Gloss retention

Standard

Durable: Class One PPC Durable: Class Two PPC Durable: Class Three PPC

30 years

1,000 hours

At least 50%

Qualicoat 16th edition

40 years

1,000 hours

At least 50%

Qualicoat 16th edition

40 years

Three years

At least 80%

Qualicoat 16th edition13

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4.20 R7, King’s Cross, London, aka ‘Pinky and Perky’, by Morris + Company, 2017; a superdurable PPC was specifed, Qualicoat Class Two, supplied by Interpon Powder Coatings with a 40-year guarantee.

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4.21 Morris + Company’s drawing of the fnely coordinated curtain walling and cladding of R7, King’s Cross, London. Key: 1. Extruded PPC aluminium fn 2. Insulated PPC aluminium spandrel panel 3. Fixed glazing 4. Extruded aluminium mullion 5. Precast concrete column

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4.22 R7, King’s Cross, London.

R7, King’s Cross is a mixed-use and ofce building, completed in 2017. The client was Argent, and the architect Morris + Company. It is known as ‘Pinky and Perky’, after the 20th-century children’s television puppets. Major PPC suppliers also ofer ranges that are memetic of other materials, from anodising, through terracotta to concrete-like fnishes. The Shard, designed by Renzo Piano and his Building Workshop (RPBW) in collaboration with Adamson Associates, is also known as the London Bridge Tower. This 72-storey mixed-use building, completed in 2012, is located at London Bridge Station on the south bank of the River Thames, in central London. This project is a response to the urban vision of the then London Mayor Ken Livingstone and to his policy of encouraging high-density development at key transport nodes in London. This sort of sustainable urban development relies on its proximity to public transport, to discourage car use and help reduce trafc congestion in the city. At 309.7m, the Shard is the tallest building in the UK and was briefy the tallest building in Europe. It is clad through with an all-glass unitised aluminium curtain walling system, designed and installed by Permasteelesa in response to RPBW’s visual and performative criteria. In total, 11,000 unitised panels of double-skinned curtain walling were used for the Shard’s building envelope. RPBW described the skin of the Shard as follows: The extra-white glass [low-iron glass] used on the Shard gives the tower a lightness and a sensitivity to the changing sky around it, the Shard’s colour and mood are constantly changing. It required a particular technical solution to ensure the façade’s performance in terms of controlling light and heat. A double-skin, naturally ventilated façade with internal blinds that respond automatically to changes in light levels was developed. The logic is very simple: external blinds are very efective in keeping solar gain out of a building, but unprotected external blinds are not appropriate for a tall building, hence the extra layer of glass façade on the outside.17 105

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The extruded aluminium sections of the curtain walling are coated in Qualicoat Class Two polyester powder coating. This super-durable polyester powder coating comes with a 40-year guarantee, subject to periodic cleaning, which is undertaken by skilled abseilers. Delaying the requirement for repainting this 72-storey building, while maintaining the visual quality of the architecture, is important for the long-term stewardship of this project. It is now possible to specify PPC that appears black (RAL 9005) to the human eye yet provides a refectance of infrared light that is 25% higher than the standard formulation of black (RAL 9005) PPC.18 Infrared light is invisible to the human eye; however, it accounts for 49% of solar gain on a sunny roof or wall. Megadur® Powder Coatings produces a Cool Coating polyester powder coating, which is Qualicoat Class Two approved, providing an ultra-durable coating that is ofered with a 40-year life expectancy until the need to repaint. The polyester powder-coated aluminium needs to be washed periodically; the frequency of cleaning is dependent on location.19 Axalta produces Alestra® Cool, which is up to 20% more refective than conventional dark polyester powder coatings. When tested, Alestra® Cool black RAL 9005 provides the same level of refectance as a standard white power coating RAL 9010.20 High-refectance powder coatings reduce the surface temperature of aluminium components, including roof sheeting, cladding and curtain walling, when subject to solar radiation. This can reduce the energy required to cool a building by limiting solar gains. Furthermore, insulation materials such as expanded polystyrene have a melting point of 80ºC. In northern Europe, a conventional black polyester coated aluminium cladding panel on a sunny summer day can easily reach a surface temperature of 90ºC, which, in the case of a composite panel, will cause delamination. Highly refective polyester powder coatings eliminate this risk.

4.23 (opposite) Guy’s Hospital overcladding, designed by Penoyre and Prasad with Arup Facades, 2014, and the Shard, designed by Renzo Piano Building Workshop, 2012: both have equally durable but distinct fnishes on their aluminium building envelopes – anodising and super-durable PPC.

Polyvinyl Fluoride Coatings Polyvinyl fuoride coatings (PVDF or PVF2) are based on a mixture of polyvinylidene fuoride resin (minimum 70%) and acrylic resin (maximum 30%). This is not commercially available in powder form and therefore needs to be sprayed using wet techniques. PVDF is a multicoat system requiring a colour coat and a top clear coat, therefore PVDF paints are relatively expensive. This method of fnishing aluminium is less economical than powder coating. However, PVDF coatings have very high resistance to ultraviolet light and are therefore popular in regions of high insolation or sun-drenched regions such as the Middle East and southern USA. PVDF coatings are not as scratch resistant as PPC, but ofer greater resistance to weathering, staining, chalking and fading.21 All prefnished components need careful coordination and protection on site; anodising, for example, will be permanently marked by splashes from concrete or mortar, leaving whiteish marks that cannot be removed. Early consideration and interaction with the potential fnishes and fnishers of the components of your next project is strongly recommended. It is the surface, the fnal microns, that arrest the eye.

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4.24 Financial Times Printworks, London, by Grimshaw and Partners, 1988. On inspection in 2012, the Duranar PVDF-coated superplastic aluminium cladding looked as new. Similarly, the silver anodised extruded aluminium cladding rails appeared ageless.

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Durability by Inspection and Testing The author investigated the durability of aluminium reviewed by inspection and testing, focusing on projects in the date range 1933 to 1989.22 All are older than the known guarantees ofered on the specifed aluminium fnishes when they were constructed.23 The buildings are a wide range of typologies – a university library, ofces, industrial, retail and housing – demonstrating that aluminium is used in all sectors of contemporary construction. The projects are still standing and all in productive use.24 Following the inspection of over 50 projects, three were selected for non-destructive testing – the anodised aluminium windows of the New Bodleian Library, 1940, by Sir Giles Gilbert Scott; the polyester powder-coated (PPC) cladding system of the Herman Miller Distribution Centre, Chippenham, 1983, by Nicholas Grimshaw and Partners; and the bronze anodised curtain walling of 1 Finsbury Avenue, 1985, by Arup Associates – as part of a Towards Sustainable Cities (TSC) research programme in 2013. The tests were undertaken by an independent testing house, Exova, facilitated by Michael Stacey Architects.25 The full results of this testing are set out in Aluminium and Durability and in a peer-reviewed paper by the author and C Bayliss, ‘Aluminium and Durability: Reviewed by inspection and testing’.26 The New Bodleian Library was constructed on a spacious site north of the Bodleian Library in Oxford, between 1936 and 1940.27 It is a steel-framed building clad in English limestone with anodised aluminium windows. Used primarily as a book repository, the New Bodleian Library, although clearly a civic work of architecture, was not a public building. It frst saw service during the Second World War under the control of British Naval Intelligence. It opened in August 1940 to mixed reviews from JM Richards and Nikolaus Pevsner.28 Gilbert Scott’s design is an example of stripped Classicism, built using contemporary construction methods. Pevsner suggests, ‘It’s not neo-Georgian by any means, yet it seems undecided how

4.25 The New Bodleian Library, Oxford, photographed in the summer of 1940.

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far the safe anchorage in history might be loosened [with] Georgian window proportions.’29 The library was Grade II listed on 1 September 2003 by Historic England.30 This listing recognises the high quality of Gilbert Scott’s design and the careful selection of materials throughout the library, recording the use of aluminium alloy windows, but with no reference to the fnish.31 In 2008, Toby Kirtley, estates project ofcer for Oxford University Library Services, observed how reliable these windows had proved in over 70 years of use.32 Gilbert Scott had used the same specifcation for the windows as at the University of Cambridge Library (1934; see Chapter 2). James Gibbons of Wolverhampton manufactured the windows for both projects.

4.26 The Weston Library (formerly the New Bodleian Library), Sir Giles Gilbert Scott, 1940, refurbished by WilkinsonEyre, 2015.

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The New Bodleian Library was renamed the Weston Library in 2015 in honour of the £25 million donation given by the Garfeld Weston Foundation. The reinvention of the library as a publicly accessible building was led by WilkinsonEyre. The expenditure on the overall refurbishment of this library was over £80 million. Following its formal reopening in March 2015, the reinvented library has received an excellent reception. It won an RIBA 2016 National Award in recognition of WilkinsonEyre’s design excellence and the sensitivity of their handling of Gilbert Scott’s original architecture. It was also shortlisted for the RIBA 2016 Stirling Prize.

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The external coating thickness of the library’s 75-year-old (when tested in 2013) silver anodised aluminium windows was measured with a dry flm thickness (DFT) meter, from a sample of 11 windows, across all four elevations, with 10 tests per window. The internal anodising of a window was tested as a control.33 Anodising was found to be present on all external surfaces, with a wide range of flm thickness, from 30.0µm to 7.1µm; on the internal side of the reference window the anodising ranged from 16.5µm to 11.0µm. Arguably, these ranges are representative of anodising thickness and variability at date of installation. Only one window tested would pass the coating thickness standard required by BS EN ISO 7599:2010. When James Gibbons of Wolverhampton organised the anodising of these windows, this was a relatively new technology, which had only been available since the 1920s (it was frst patented in Japan in 1923).34 Based on the durability of the anodised aluminium windows, the design team decided that the windows were satisfactory for another 60 years or more, requiring only cleaning and reglazing. 4.27 Inspection and nondestructive testing of the anodised aluminium windows of the library during its refurbishment.

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4.28 (below right) Herman Miller Distribution Centre, Chippenham, by Nicholas Grimshaw and Partners, 1983, photographed in 2013.

4.29 (below) Detail by Nicholas Grimshaw and Partners showing the interchangeable pressed aluminium cladding panel of the Herman Miller Distribution Centre – a simple neoprene gasket provides weatherproofng at each vertical joint.

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The Herman Miller Distribution Centre, in Chippenham, designed by Nicholas Grimshaw, with project architect Neven Sidor, was completed in 1983. This award-winning building was very successfully used by Herman Miller until 2017.35 The fexible and interchangeable panel system, based on a 2.4m by 1.2m grid, has proved its value in the ease with which Herman Miller added a new roller shutter door to the eastern end of the south façade. Farrell and Grimshaw’s earlier Herman Miller Factory in Bath, completed in 1977, is clad in beige-coloured glass-reinforced polyester (GRP) interchangeable panels. For the Chippenham building, 2mm-thick pressed aluminium panels were manufactured by Kinain Workshops and fxed by RM Douglas. They were polyester powder coated by Acorn Anodising, using three blue Syntha Pulvin polyester powders: the panels and windows used light blue – RAL 5012; the external pods used dark blue – RAL 5010; and the T-Bar aluminium extrusion used cobalt blue – RAL 5003. All were gloss, with 100% refectivity, as this was the only option for PPC at the time of specifcation. All three blues, exposed to prolonged sunshine over 30 years, have faded. This is particularly noticeable on the RAL 5012 panels. The average gloss level result for the exposed light blue panels was 18.4%, for dark blue panels was 7.6% and for cobalt blue extrusions was 10%. Considering the PPC had been exposed to weathering for 30 years when tested in 2013, fading and loss of gloss is not surprising. Current formulations, pre-treatment, manufacturing and installation of PPC aluminium are much more durable than those of the 1970s and 1980s, benefting from extensive research and long-term testing in areas of high insolation, such as Florida, USA.36

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4.30 A DFT meter, used to measure coating thickness, and an x-Rite colour meter.

4.31 Geof Addicott, of Exova, undertaking the nondestructive testing at Herman Miller Distribution Centre, Chippenham, October 2013.

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4.32 Valspar Powder Coatings: typical contemporary performance of polyester powder coatings, based on Florida high-insolation testing.

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1 Finsbury Avenue, a purpose-built office building in London, was designed by Arup Associates, completed in 1985, and was Grade II listed by Historic England in 2015.37 The sophisticated suite of bronze anodised aluminium extrusions, which forms the curtain walling, brise-soleil (access walkways) and cladding were designed and engineered by Josef Gartner of what was then West Germany, at the time the best curtain walling company in the world.38 1 Finsbury Avenue now sits comfortably within a well-considered, treelined hard landscape, forming the first phase of the Broadgate ‘groundscraper’ development. This is a sophisticated work of architecture that reflects Arup Associates’ expertise as a multidisciplinary practice and its expertise in the design of offices, including Gateway 1 (1976) and 2 (1984) in Basingstoke. The design of the curtain walling system with bespoke extrusions by Gartner is equally sophisticated. The bronze anodising is generally in very good condition, having weathered in a very similar manner to bronze itself. When tested in 2013, the thickness of bronze anodising on the curtain walling ranged from 19µm to 37µm, with an average value of over 25µm. The reference sample, which had been indoors for the past 28 years, exhibited a range of 22µm to 26µm and an average value of just over 24µm; it should be noted that this is only a short section of extrusion. Both external and reference samples are just outside the BS/EN/ISO 7599:2010 standard for 25µm external anodising, which states a minimum of 80% of the specified thickness (achieved by the reference; narrowly missed by four of the six external curtain walling samples) and an average equal to or greater than the specified value of 25µm (narrowly missed by the reference and three of the six external samples).

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4.33 1 Finsbury Avenue, London, by Arup Associates, 1985, with bronze anodised curtain walling by Josef Gartner.

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The timescales for the durability of aluminium demonstrate that the service life of aluminium windows, used by organisations including building research establishments, should be at least 80 years. Site- or programme-specifc issues may limit these life expectancies, such as the use of aluminium within a swimming pool or an aggressive industrial interior. For PPC, the recoating methods need to be well specifed, but the oldest PPC aluminium still in service in the Towards Sustainable Cities study is more than 45 years old (in 2023) and has not been recoated, while the guarantees ofered in 1973 were only 10 years. The oldest example of PVDF-coated aluminium reviewed is more than 30 years old (in 2023) and is very similar in appearance to its frst inspection in 1988. Aluminium-based architecture is performing well in our towns, cities and rural landscapes. The durability of this aluminium architecture should be recognised and celebrated.

4.34 (opposite) The southeast façade of 1 Finsbury Avenue, London.

4.35 A reference sample bronze anodised aluminium extrusion was taken to site for testing, November 2013.

4.36 Non-destructive testing of 1 Finsbury Avenue, London.

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5.1 The visible materials of the interior of the Bridge of Aspiration are oak, aluminium and glass.

CHAPTER 5

Light and Strong The role of lightness is less apparent in architecture and the built environment when compared to aerospace and transportation. Perhaps lightness is a useful metaphor when designing: to touch the earth lightly. In many applications, lightness is equally important in architecture, be this the craning of large prefabricated building assemblies, the placement of slab formwork for the casting of concrete or the carrying of components by hand by a single worker (which needs to be under 25kg to follow contemporary health and safety guidance).1 The high strength-to-weight ratio of aluminium produces building components that use less energy to transport, less energy to install and less energy to disassemble. Inspired by Richard Neutra’s Lovell Health House (1929), Chris Lowe’s brief for an apartment in central London with views of St Paul’s Cathedral was to be able to sleep under the stars, despite the apartment being part of a warehouse conversion. A key element of Brookes Stacey Randall Fursdon’s response to this brief was simply to open up a complete section of roof above the sleeping mezzanine. This was achieved by working with four specialist subcontractors, synthesising their contributions and delivering the roof light as a complete prefabricated product. Therefore, the light weight and strength of aluminium was key in the framing and in the solar shading. The total weight of the roof light was important for transportation and the crane lift into place. It is also of vital importance to the hydraulic operation of this roof light on a day-to-day basis.

5.2 Craning the aluminiumbased prefabricated roof light of the Lowe Apartment, London, designed by Brookes Stacey Randall Fursdon, 1997.

5.3 Guidance on lifting and lowering from the Health and Safety Executive’s Manual Handling Operations Regulations (1992).

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5.4 The roof light forms a complete section of roof in the Lowe Apartment, which opens up to enable the owner to sleep under the stars, even in central London.

5.5 The sleeping mezzanine in the Lowe Apartment is accessed via a structural glass staircase designed by Brookes Stacey Randall Fursdon with engineer Tim Macfarlane.

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5.6 The Ski Haus, designed by Richard Horden Architects, being lowered onto the Swiss– Italian ridge in the Alps at about 3,980m above sea level.

A dramatic example of lightweight prefabrication using aluminium is Richard Horden’s Ski Haus (1991). This hard tent needs to be lifted into place with a helicopter at diverse locations in the Alps. Richard Horden observed, ‘It is nearly 100% aluminium and when empty weighs just over 300 kilos.’2 The Ski Haus serves very successfully as a refuge for climbers and skiers. The primary advantages of prefabrication are: • speed of construction • factory-based quality control • controlled condition of a sheltered factory environment • minimisation of waste combined with closed-loop recycling of ofcuts • a better gender balance is often found in factories compared to building sites. In 1941, de Havilland developed a jet aeroplane, codenamed Spider Crab, using a jet engine of its own design, but based on Frank Whittle’s jet engine invention, lodged with the Patent Ofce in 1935. This jet fghter, with its all-aluminium construction, frst few in 1943, becoming the successful DH 100 Vampire fghter. It entered service with the RAF in 1945. However, Sir Geofrey de Havilland’s primary interest was civilian aircraft and in February 1945 his company commenced the design development of the de Havilland DH 106 Comet, the world’s frst commercial jetliner.3 On 27 July 1949, test pilot John Cunningham few the Comet One prototype for the frst time, from de Havilland’s Hatfeld Airfeld, in Hertfordshire. To test, develop and maintain the Comet, de Havilland realised it needed a hangar and other facilities to support this process. Based on its experience using aluminium to build aircraft, de Havilland encouraged its architect, James M Monro & Son, to use this light metal for the construction of the hangar. 121

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5.7 A row of de Havilland Vampire fghter jets and a Comet jetliner in the Comet Flight Test Hangar, 1955.

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The Comet Flight Test Hangar, at Hatfeld, Hertfordshire, has a clear span of more than 66m, comprising 12 aluminium portals set at 9.14m centres with the roof generously oversailing the full-width sliding folding doors at the southern and northern ends. Across the span, the portals have a constant depth of 3.05m and the legs are 2.44m deep, except at the knee brace that links these two elements forming a stif portal. The structure was designed to the loading criteria in BS 449: 1948. The structure creates a useable foor space of 61m by 100.58m combined with a clear height of 13.72m.4 The aluminium structure was designed by Structural and Mechanical Developments Engineers Ltd in close collaboration with the architect. The components of this riveted aluminium structure were extruded using HE 10 WP aluminium alloy in accordance with BS 1476, supplied by Southern Forge Ltd and TI Aluminium Ltd. The roof takes the form of a sawtooth with trapezoidal roll-formed aluminium alloy sheeting, supplied by British Aluminium Co, 12.7mm (½ inch) of insulation and two layers of bitumen felt with a mineralised fnish on the southern roof pitches. The roof sheeting was roll formed from NSE ¾ H aluminium alloy in accordance with BS 1476. The Comet Flight Test Hangar is a generously daylit workplace. Each portal supports 23 north light trusses. The north lights are 2.82m deep with extruded aluminium glazing bars at 2.82m centres supporting 6.3mm- (¼ inch) thick Georgian wired clear cast glass. The HE 10 aluminium alloy was selected for its high strength-to-weight ratio. This aluminium portal framed structure weighs only one-seventh of an equivalent steel structure. Aluminium was chosen for its material efciency and it enabled large-scale prefabrication and rapid assembly on site. The components of the aluminium structure were cold riveted in controlled factory conditions. The cold-squeezed rivets were made from NE5 and NE6 aluminium alloys and were 9.53mm (⅜ inch) and 15.88mm (⅝ inch) in diameter. The cold-squeezed rivets are driven by a yoke exerting 22.68-tonne pressure, and do not contract on cooling as experienced in hot riveting, thus each rivet totally flls the hole in the sections being fxed together.5 This aluminium structure was erected in 13 weeks by 18 people using little scafolding and two 4.4-tonne hand-operated cranes.6 The Architect’s Journal technical editor, R Fitzmaurice, noted that aluminium was chosen as ‘large factory elements can be more easily transported and more work done in the factory’.7 The prefabricated components of the aluminium structure were bolted together on site using sherardized turned and ftted steel bolts and spun black galvanised bolts connecting the sections with gusset plates, comprising either 9.53mm-thick (⅜ inch) or 12.7mm-thick (½ inch) aluminium. The pins at the base of the portals are prevented from spreading by 457.2mm by 457.2mm (18 inch by 18 inch) prestressed concrete ties, using the Freyssinet system.8 The east façade and west façade are clad in sinusoidal aluminium sheeting. The hanger was completed in 1953, followed by the ofces and fight control tower in 1954. If the 18-year-old Norman Foster, yet to attend Manchester School of Architecture, had in 1953 asked James Monro how much this aluminium-structured aircraft hangar weighed, he could have turned to the table published in Architect and Building News, reproduced in Table 5.1

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Table 5.1 The weight of the Comet Flight Test Hangar and its components, in SI units.

Element or components

Structural sections Plate Sheeting Roof decking Glazing Lining Steel components Total weight of aluminium Total weight of other materials Total weight Weight kg per m2

Aluminium

Other materials

tonnes

tonnes

96.13 36.29 9.07 36.29 3.63

113.40 25.40 9.98 28.12

181.44 176.90 358.40 58.44

using SI units.9 Fewer than 182 tonnes of aluminium were used to fabricate and clad this aircraft hangar, with an almost equal quantity of other materials. The hangar area is 6,131.6m2 and it weighs 58.44kg per m2. The Welwyn Hatfeld Times observed that de Havilland had ‘this hangar completed within 12 months of asking for it’.10 Architect and Building News found it ‘interesting to note that in a building of this size, aluminium structures are economically competitive with steel and reinforced concrete, particularly when ease of erection and availability of material is taken into consideration. Furthermore, the structural designers may calculate the economic size of a member and have an extrusion die made so that the exact section required is used.’11 John Peter in 1958 heralded the hangar as ‘a structure every bit as dynamic as the jetliners it shelters’.12 5.8 Cold riveting the aluminium trusses for the Comet Flight Test Hangar using a suspended half-ton yoke.

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On 21 September 1998 Historic England listed the complete Comet Flight Test Hangar, ofces, fre station and control tower Grade II*. The listing observes that the ‘Comet Hangar was the most sophisticated example of aluminium construction and was also the world’s largest permanent aluminium structure at the time, comparable with the demolished Dome of Discovery at the Festival of Britain and more innovative than the hangar at London Airport’.13 This smaller aluminium structured hangar, with a 45.72m clear span,14 at London Heathrow Airport, renamed in 1966, has also been demolished. The Dome of Discovery is discussed in Chapter 8.

5.9 The Comet Flight Test Hangar, ofces, fre station and control tower, photographed in 1954, shortly after completion.

The frst BOAC Comet Jetliner completed a scheduled fare-paying journey on 2 May 1952, fying from London to Johannesburg. With its fast and smooth operation, large – almost square – windows and pressurised cabin, at frst the Comet appeared to be a great success. Queen Elizabeth II, the Queen Mother and Princess Margaret few on a Comet as guests of Sir Geofrey and Lady de Havilland in 1953. However, the UK’s pioneering of mass air travel was soon to meet a series of fatal setbacks. Historic England frequently cites technological reasons for the listing of buildings, both innovative means of construction or ground-breaking work by the users of a work of architecture. However, the listing for the Comet Flight Test Hangar is the only listing citation to discuss fatal air accidents: ‘Between 1953–4 three Comets exploded in the sky, and 11 people were killed.’15 This led to a ground-breaking testing programme. These tests found that the stress at the abruptly radiused corners of the windows was much higher than expected. The failure was caused by metal fatigue, due to 125

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5.10 In 2004, the Comet Flight Test Hangar was converted into a tennis club and hotel by Roberts Limbrick Architects.

5.11 View across two of the tennis courts in the former Comet Flight Test Hangar, looking north, photographed in 2016.

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stress reversal resulting from the pressurisation cycles. The Comet Four frst few on 27 April 1958; the frst fight of a Boeing 707 was 17 October 1958. De Havilland had lost its lead in the design and construction of jetliners. In 2004, the Comet Flight Test Hangar and related facilities were converted by Roberts Limbrick Architects into a Tennis Club and Hotel. In the spring 2016, the author revisited the hangar at Hatfeld. The airfeld is long gone, replaced by housing, business buildings and a university campus. However, the 66m-span aluminium hangar remains and is full of people engaging in exercise, even on a weekday.16 This early high-tech shed has become a fun-palace. The most visible activity is tennis, being played and tutored in generous daylight, yet the players of all ages are protected from the vagaries of the British weather, just as the Comet jetliners were in the 1950s. The Comet Flight Test Hangar appears to be a triumph for the listing of technologically and culturally signifcant architecture as the spirit of the space lives on and is full of life. The mill-fnish aluminium structure, which was pressure-washed in 2004, is brightly refective: after more than 50 years, it appears to be a contemporary new build structure. The success of the Comet Flight Test Hangar begs the question why there have not been more roof structures built using aluminium, when the saving in self-weight is such an important issue for roof structures. Furthermore, in the 21st century we have vastly improved extrusion techniques, have a wider range of aluminium alloys and have improved joining techniques for aluminium, including welding. In 2007 Eurocode 9 was introduced for the Design of aluminium structures.17 5.12 The former Comet Flight Test Hangar’s aluminium structure and aluminium roof deck, photographed in 2016, remain highly refective, looking like the roof of a contemporary project.

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Lord’s Cricket Ground is the home of Marylebone Cricket Club (MCC), which was founded in 1787 and moved to its current location in St John’s Wood, London, in 1814. It is named Lord’s in honour of the founder of MCC and original owner of the ground, Thomas Lord.18 By the mid-20th century, Lord’s was a wonderful ground to watch test cricket, and architecturally it was characterised by the handsome faience-clad Victorian pavilion designed by architect Thomas Verity, built in 1889–90. Starting with the Mount Stand by Michael Hopkins Architects, completed in 1987, MCC became one of the most unexpected patrons of cutting-edge contemporary architecture. In 1995, Future Systems, led by architect Jan Kaplicky, won the MCC’s competition for a new media centre with an audacious proposal for a ‘glass-fronted white aluminium disk, raised on two legs’ and hovering above the stands.19 Prefabrication was key to this project, as it had to be built outside the cricket season to avoid disturbing games. Kaplicky, who worked at Foster Associates before founding his practice, had a long-held interest in new technology: often technology that had long roots but was being underused by the construction industry. The Lord’s Media Centre ofered the opportunity to explore and realise a monocoque aluminium structure. The scale of this cantilevered aluminium structure necessitated the use of internal stifening ribs, generating a semi-monocoque structure. Deyan Sudjic records that during the design development process, glass-reinforced plastic (GRP) was considered, but, ‘Future Systems were determined to use aluminium, conceptually a much more elegant material.’20 The thickness of aluminium used to form the components, or prefabricated ‘chunks’, of this semi-monocoque structure varies between 6mm and 18mm, depending on the structural design of the shell. 5.13 Lord’s Media Centre, by Future Systems, 1999, photographed in 2022, with the Compton Stand, by WilkinsonEyre, 2021.

5.14 Jan Kaplicky’s sketch of the Media Centre at Lord’s Cricket Ground.

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5.15 (top) Future Systems’ section through the Lord’s Media Centre.

5.16 (above) The trial assembly of the Lord’s Media Centre by Bayards in its main hall in Nieuw-Lekkerland.

5.17 (left) The aluminium semimonocoque structure of Lord’s Media Centre.

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5.18 Lord’s Media Centre under construction in 1999, clearly showing the prefabricated aluminium components.

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Future Systems appointed Pendennis, a shipbuilder from Falmouth in Cornwall, as the specialist contractor. The Media Centre was, however, fabricated in the Netherlands by Bayards in its main hall in Nieuw-Lekkerland. The prefabricated components were then transported to site in London, temporarily supported and then site-welded into a single shell. The welding of aluminium should no longer be considered difcult, although it is a highly skilled activity. By the early 1990s, the techniques of welding developed in the factory or fabricating yard could be reliably applied to site conditions.21 For example, TIG (Tungsten Inert Gas) welding can be carried out on site-based aluminium components at a range of 200m from an appropriately equipped van. On completion of the welding of the semi-monocoque structure of the Media Centre, a high-performance white paint system was site applied. Completion of the project took two winters and it opened in 1999.

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Lord’s Media Centre has proved a great success, providing uninterrupted sightlines for journalists and commentators in the comfort of air-conditioning. Deyan Sudjic considers the white aluminium shell ‘to hover above the ground, an enigmatic, ambiguous form, whose scale and form are initially hard to read’.22 It both signals the presence of the Test venue and it ‘has become a defining image of Lord’s, even though this last quality was never part of the brief.’23 In 1999, the Lord’s Media Centre won the RIBA Stirling Prize, the highest honour available in UK architecture. Between the Pavilion and the Media Centre at Lord’s lies a field of dreams and over 100 years of technological advancement in the potential for constructing architecture. Vague Formation Mobile Music Pavilion, designed by architects Kristina Schinegger and Stefan Rutzinger of soma, was the winner of an open, two-stage competition in October 2010.24 It was erected for the first time in the historic centre of Salzburg in March 2011 for a period of three months and housed the contemporary music festival Salzburg Biennale. Subsequently, it has been assembled in Krakautal, Austria, and Maribor, Slovenia. The aluminium structure was designed parametrically, but the diversity of components often associated with freeform geometry was eschewed in favour of aggregating a standard component. Working with engineer Bollinger + Grohmann, soma developed a bottom-up design strategy based on a repetitive element that does not change shape, yet creates a palette of spatial patterns depending on the rules of aggregation. The base component is a mill-finish aluminium box section 100mm by 100mm with a wall thickness of 4mm extruded from a standard stock die. To facilitate transportation, the structure of the pavilion is divided into five-arched segments that in turn are broken down into six sub-segments.

5.19 Vague Formation, by soma, Salzburg, 2011.

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5.20 Sample images of the design team’s parametric model of the structure of Vague Formation.

5.21 Vague Formation: formed from standard extruded aluminium box sections, yet it is an apparently random structure.

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The architects did not want the construction to be read in a conventional manner – in contrast, for example, to Renzo Piano’s travelling IBM exhibition pavilion from the early 1980s, which was formed from arched bays of polycarbonate and timber linked by elegant aluminium castings.25 The aluminium structure is prefabricated in 95 layers or arches – each arch spans 10m and has a unique aggregated curvilinear geometry. The aluminium box extrusions are welded together with 90mm-long circular aluminium extrusions, where layers of arches are bolted together during erection; these 90mm-long circular aluminium extrusions conceal the M10 stainless-steel connecting bolts. The expression is based on aggregation rather than articulation of the detailing. The apparent complexity is underscored by the clarity of the fabrication. It generates a striking and delightful architecture both inside and outside; appropriately, this could be seen as a contemporary example of architecture as frozen music.

Aluminium Bridges Durability is very important in the design and construction of bridges. In the UK, bridges in the public realm are designed to last at least 120 years, subject to annual inspection and appropriate minor maintenance, if necessary. The oldest extant aluminium bridge is Arvida, a road bridge spanning the Saguenay River at Saguenay–Lac-Saint-Jean in Quebec. It was built between 1948 and 1950. It is 10.4m wide, 154m long and the primary arch spans 88.4m. This bridge, fabricated from 2024-T6 aluminium alloy, is still performing well, having been refurbished in 2013–14. Since the mid-1990s, architects have increasingly become involved in bridge design – linking the art and science of construction. Typically, bridges have a very clear identity and the design of bridges is not unlike product design. Architects bring to a bridge design skills in being able to access and analyse the context, releasing the spatial potential of the bridge. Providing a holistic approach to all of the components of a bridge, in essence the whole becomes greater than the sum of the parts.

5.22 Arvida Bridge, 1950, an all-aluminium road bridge spanning the Saguenay River.

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The Bridge of Aspiration, in Covent Garden, London, was completed in 2003. The brief WilkinsonEyre received called for a bridge crossing Floral Street, to link the Royal Ballet School with EM Barry’s Royal Opera House, and to provide direct access for the dancers to rehearsals and performances. It also encourages young dancers to mix with professionals in the cafes of the Royal Opera House. Two existing openings were identifed; however, they were asymmetrically placed in terms of both plan and level above the street. Jim Eyre’s initial sketch, sent to structural engineers Flint & Neill, was a series of rotating squares in space translating the geometry between the two buildings and resulting in a gently ramped walking plane. This movement of frames in space is reminiscent of the display Ripley is viewing in the landing sequence in Ridley Scott’s science fction movie Alien, released in 1979.

5.23 The Bridge of Aspiration, viewed from Floral Street, Covent Garden, London, by architect WilkinsonEyre and engineers Flint & Neill, 2003.

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The realised design is composed of 23 aluminium frames, each rotated in space by 3.91°. The frames are linked together by a twisting aluminium box beam, which is only apparent during assembly. The bridge is articulated by the rotating aluminium frames and united by a glass skin that is translucent and clear. The translucent glass conceals the structure but more importantly provides privacy for the dancers from the street below. This gives way to clear glass that provides views out. One way of reading this bridge is the interplay of two forms, each made of translucent and clear glass. Internally, the aluminium frames are

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5.24 Jim Eyre’s initial drawings of the Bridge of Aspiration: the ends and centre are key drawings in the design of all bridges.

5.25 The Bridge of Aspiration was delivered digitally following the initial sketches – this image shows the 23 rotated frames of the bridge.

5.26 WilkinsonEyre’s plan of the Bridge of Aspiration.

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5.27 The assembly of the twisted aluminium spine beam of the bridge at GIG’s north London facility.

5.28 (above left) The Bridge of Aspiration being trucked across London to Covent Garden.

5.29 (above right) The Bridge of Aspiration being craned into position, London, WilkinsonEyre with engineers Flint & Neil, 2003. The bridge links the Royal Ballet School with EM Barry’s Royal Opera House.

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partially clad in oak, to accommodate the glass that is not parallel with the mullions and to accentuate the reading of the twisting geometry. Oak is also used to form the walking plane or foor. The Bridge of Aspiration was totally prefabricated by Austrian company GIG in its north London facility, which is more typically used for prefabricating unitised curtain walling. Thus, GIG has all the advantages of the controlled conditions of factory production yet avoids transporting large prefabricated assemblies across continental Europe and the Channel. The bridge is literally a translation in space; however, it also serves as a metaphor of the movement of a dancer through space, an architectural overture of the performance in the Royal Opera House – just a few dance steps away across Floral Street.

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5.30 Carefully positioning the bridge to match the asymmetrical openings of the Royal Ballet School and the Royal Opera House.

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5.31 Westdork Bridge, Amsterdam, designed by MVSA Architects, fabricated by Bayards, 2003 – an allaluminium bascule bridge.

5.32 Westdork Bridge, Amsterdam, opening at dusk.

5.33 St Clements’ Bridge, Victoria Dock, Aberdeen, 1953.

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Westdork Bridge is a 5m-wide and 48m-long bridge over an Amsterdam canal for pedestrians and cyclists. The central span is a 16m single-leaf bascule to allow boats to pass. The bridge was designed by MVSA Architects and fabricated by Bayards; it was assembled in 2003.26 The client for this bridge was the Amsterdam City Development Corporation. The lightweight all-aluminium structure of this opening bridge facilities its day-to-day operation. Bayards actively promotes collaboration with architects in the design of bridges, using its experience in designing and fabricating prefabricated assemblies in aluminium since 1963. Bayards manufactures structural assemblies from aluminium on a bespoke basis using robust and reliable technologies. This can be contrasted with Sapa’s standardised approach to the design of bridge decks, which is discussed below. The world’s frst aluminium bascule bridge was built in the UK in 1948, serving Hendon Dock in Sunderland. It was built by Head, Wrightson & Co of Stockton. This bridge was 37m long and 5.64m wide. The second aluminium bascule bridge, St Clements’ Bridge, was assembled at Victoria Dock in Aberdeen, by Head, Wrightson & Co, to a similar specifcation, but it was only 30m long.27 It was opened by the Queen Mother on 30 September 1953.28 Both bridges were decommissioned in the 1970s.

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Blainville Equestrian Park Bridge, in Blainville, Quebec, was designed for use by pedestrians, horses and riders and opened in 2012. It is an 18m single-span all-aluminium bridge with a clear width of 3m and a self-weight of almost 7 tonnes or 380 kg/m. It was fully prefabricated in Boucherville, Quebec, by MAADI Group. It is an open truss with a gently curved profle fabricated from MIG (Metal Inert Gas) welded, square hollow section (SHS) aluminium extrusions in two sizes, 125mm and 150mm. This mill-fnish, single-span aluminium bridge rests on simple concrete abutments. It also has an Ipe hardwood deck and kick plates with aluminium guardrails.

5.34 Blainville Equestrian Park Bridge, an aluminium bridge with a hardwood deck, designed and fabricated by MAADI Group.

An All-Aluminium Pedestrian Bridge Linking Two Oil Rig Platforms was also designed and fabricated by MAADI Group. It spans 46.3m between two platforms and is a walk-through box truss with a clear width of 1.2m. It has an aluminium grip span® deck, aluminium kick plates and guardrails. The self-weight of the bridge is only 13.7 tonnes or 296 kg/m. The bridge is fabricated from welded 150mm and 200mm SHS aluminium extrusions, using a combination 5083-H321 and 6061-T6 alloys, all left mill fnish. It will require very little maintenance, even in an exposed maritime location. Both 139

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5.35 A 46.3m oil rig pedestrian bridge, designed and fabricated by MAADI Group. This allaluminium bridge links two ofshore platforms. (Published with permission of the oil extraction company.)

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MIG and TIG welding was used to fabricate this bridge. It was fully prefabricated in Boucherville, Quebec, shipped to site in fve 12.2m shipping containers and installed as a single-span element. MAADI Group produces a diversity of aluminium pedestrian bridges, typically based on welded fabrication. However, it has also developed weld-free prefabricated aluminium bridges, including a rapidly deployable military bridge for the Canadian armed forces.29 Designed for pedestrian and light vehicles to overcome obstacles in the battlefeld, such as rivers and ravines, this bridge has an overall length of 18.3m, to be able to span a maximum 16m, with a clear width of 1.5m. Eight to ten people can deploy the bridge in 80 minutes. The quick-ft prefabricated assembly of aluminium components is locked of with stainlesssteel bolts, with reusable stainless-steel split pins on stainless-steel wire tethers.30 It has a capability of being crossed by 127 soldiers if their weight is well distributed. The vertical frequency of this bridge is 5.8Hz, signifcantly greater than the 3Hz required by the AASHTO (American Association of State Highway and Transportation Ofcials) LRFD Code for the Design of Pedestrian Bridges (2009). The guidance to this code refers to the problems on the Millennium Bridge in London and states that the lateral frequency needs to be above 1.3Hz.31 The bridge can also carry small vehicles, such as snowmobiles and quad bikes up to 500kg.32

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5.36 A prototype of a rapidly deployable military bridge with a maximum span of 16m, Canada, designed and fabricated by MAADI Group, 2016.

5.37 Canadian Army soldiers assembling (a) and then using (b) the prototype rapidly deployable military bridge.

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The bridge is assembled from modular aluminium components and the key detail of the trusses are cast aluminium tripods. The trusses are preassembled into four sections and then bolted together. The aluminium deck panels pivot on one tubular crossbeam and clip onto the next one; the deck panels also interlock to help secure the complete bridge deck. Once the bridge has been assembled, typically it is launched into position from one bank. As soon as it is correctly located, each end of the bridge is jacked up and bearings are fxed in place. With training, all this can be achieved in 80 minutes, less time than a feature flm. The bridge is operational and the obstacle has been overcome. The military version of MAADI Group Make-A-Bridge® is an exemplar of Design for Assembly (DfA) and Design for Disassembly (DfD).33 It is also an excellent example of the versatility of aluminium, providing fexibility in design and realisation. Alexandre de la Chevrotière, CEO of MAADI Group, considers that ‘this product would not be possible without the capabilities of aluminium extrusions’.34The aluminium extrusions of this deployable military bridge were fabricated from 6005A-T6 and 6061-T6 alloys, with the nodes cast in AA357-T6 alloy. The stainless-steel bolts are coated with Xylan® 1424, a fuoropolymer that contains PTFE (polytetrafuoroethylene), providing corrosion protection and friction resistance. The bridge is polyester powder coated in Canadian Army dark olive green. The complete bridge only weighs 1,970kg or 69.9 kg/m2, a direct equivalent to the average weight of a Canadian citizen per m2, and at least half the dead weight of an equivalent steel bridge.35 In 2016, the 5e Combat Engineer Regiment of the Canadian Army tested the prototype for sixth months, including airlifting the bridge into remote locations by helicopter. Prior to this, the prototype bridge was load and vibration tested by the Engineering Faculty of the University of Waterloo.36 5.38 In 2020, MAADI Group designed and fabricated a longer and stronger version of the Tactical Bridge for the Canadian Army, capable of supporting vehicular loads of 2.5 tonnes (MLC6/Military Load Classifcation 6).

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5.39 The components of the Canadian Army Tactical Bridge.

5.40 The Canadian Army Tactical Bridge is deployable in 4m modules up to 24m.

In 1987, Sapa in Sweden developed a system of aluminium extrusions to form structural road bridge decks, targeted primarily at replacing failed wooden or concrete decks on existing bridges. To date it has completed almost 80 projects in Sweden and Norway.37 The system, invented by Lars Svensson, comes in two depths – 53mm extrusions to replace wooden decks and 101.5mm extrusions to replace concrete decks. The 53mm-deep extrusions are 250mm wide and the 101.5mm-deep extrusions are 280mm wide. In both cases, the extrusions run transversely across the bridge, supported by edge beams. Many extrusions are required to form a complete bridge deck. Sapa’s factory in Finspäng is equipped with friction stir welding machinery capable of welding panels of extrusions up 14.5m long by 3m wide, a good size for bridge deck applications. A good example of the deployment of the 101.5mm-deep Sapa aluminium bridge deck system is the Tottnäs Bridge, 55km south of Stockholm. This multi-span bridge had its deck replaced in 1989, without the need to replace the foundations, the four piers or the abutments.38 The US Federal Highway Administration, in its 2014 National Bridge Inventory, identifed that more than 600,000 bridges in the USA are structurally defcient and thus there is an urgent need for bridge and bridge deck replacement.39 143

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5.41 The Sapa extruded aluminium bridge deck system: 101.5mm by 280mm extrusion cross section, as used on Tottnäs Bridge, Stockholm; Sapa Bridge Deck System: Inventor Lars Svensson, 1989.

5.42 WilkinsonEyre’s sketch analysing the context of Lockmeadow Footbridge, Maidstone. (North is to the left of this sketch.)

Research undertaken in Canada by Deloitte (2012) using life cycle assessment (LCA) compared pedestrian bridges assembled from galvanised steel and mill-fnish aluminium, considering all phases of the bridges – acquisition; design and construction; maintenance and operation; and end-of-life. The last phase includes the costs and revenues associated with the disassembly, removal, recycling of materials and site remediation.40 This research demonstrated the economic advantage of specifying a low-maintenance aluminium bridge. Over a 50-year timescale, an aluminium bridge in an urban environment is signifcantly more economical than a galvanised steel bridge, and in a marine environment it is more economical in only 21 years.41 The River Medway was the main trade artery and the reason for the growth of the county town of Maidstone in Kent, until the arrival of the railways in the mid-19th century. Lockmeadow Footbridge, designed by WilkinsonEyre with structural engineers Flint & Neill and completed in 1999, has a structural aluminium deck that is only 300mm thick and spans 80m, supported by cable stays from two masts at mid span that spring from the cutwater. The context of the bridge is Grade I listed buildings that date back to the 14th century. These are all located on the town side (the east bank of the River Medway), as shown in Figure 5.42, WilkinsonEyre’s analysis of the context of the bridge. To the north is the Archbishop’s Palace and All Saints Church and to the south the Gateway, which is the remains of All Saints College. The footbridge gently curves on plan as it spans over to the opposite bank of the Medway. It spans beyond the spring points of its masts to allow the water meadow of the west bank to food. The commission to design this footbridge was won by WilkinsonEyre in a competition in 1997 – the competition brief ‘called for a design that was sensitive both to the location and to the modern idiom’.42 Jim Eyre, founding Director, reports:

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Lockmeadow uses a bespoke aluminium extrusion in a very specifc way. Flint + Neill, the structural engineers, and WilkinsonEyre took out a patent on the system. One advantage, other than the ability to ‘laminate up’ a curved plan, was that from the 300mm depth we could get quite long spans, some 16m provided there was continuity over the supports.43

5.43 Cross section of Lockmeadow Footbridge showing the structural extruded aluminium deck.

WilkinsonEyre’s design for this footbridge combines an economy of means, which also minimises the visual intrusion of the bridge crossing the Medway. The structural aluminium deck is made up of pairs of an open E-like extrusion. This extrusion has bilateral symmetry, meaning that only one die and one type of section is required to form both sides of the ridged cells, which are linked by solid aluminium central rectangular extrusions and aluminium fats in the top of the deck only. This assembly forms stif structural cells by post-tensioning in the transverse direction, from the penultimate extrusion of each side of the deck. The fnal extrusions form a clean edge to the aluminium deck, as they are only fxed via the balustrade post fxings. Slipping the linear extrusion during assembly enables the gently curved plan to be achieved. The top surface of the E-like extrusions is ribbed to form a safe walking and cycling surface. 145

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5.44 The structural aluminium deck of Lockmeadow Footbridge is assembled from E-like aluminium extrusions.

5.45 The 14th-century Archbishop's Palace viewed through the 20th-century Lockmeadow Footbridge.

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5.46 Ballingdon Bridge, viewed from the water meadows of Sudbury, by Michael Stacey Architects with engineers Arup, 2003.

In the summer of 2000, Michael Stacey Architects won an RIBA competition to design Ballingdon Bridge in collaboration with structural engineers Arup and specialist lighting designers Evolution.44 The setting as it crosses the river Stour is a wonderful combination of a water meadow that surrounds Sudbury and the listed buildings that form the town and the village of Ballingdon (see Figure 5.46). The design development of Ballingdon Bridge is described in Concrete: A Studio Design Guide;45 of key relevance is the bespoke aluminium and stainless-steel balustrade system. The balustrade was designed to be visually open so that the views of the landscape are as uninterrupted as possible. It is capable of arresting a 42-tonne truck yet appears to be an elegant pedestrian handrail, its strength being achieved by a combination of stainless-steel castings, stainless-steel wires and two bespoke aluminium extrusions. The tensile strength of the aluminium is vital in stopping a truck from falling into the river. The illuminated bollards were designed for the project to avoid the need to use lampposts on the bridge. Cased in waterjet-cut anodised aluminium, the core of each bollard is a galvanised circular hollow steel section, which will stop cars from crossing the pavement, but shear of if hit by larger vehicles. The bollards were prototyped at one-to-one using white watercolour paper and discussed with the client on the earlier (1911) bridge. The top rail of the balustrade is a combination of extruded aluminium and English oak. This point of human contact is key to its design; to a pedestrian, the vehicular safety role of the balustrade is intended to be an unseen quality. The enlarged oak walkways create a generous provision for pedestrians to enjoy the views of the river and meadows. People enjoying the river and the urban spaces of Ballingdon and Sudbury are the priority within the design of this road bridge. The quality of design and the quality of thought embodied in this bridge was recognised by national and international design awards, including an award from the Campaign for the Preservation of Rural England. 147

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5.47 The balustrade of Ballingdon Bridge was designed to be visually open yet it is capable of stopping a 42-tonne truck from falling into the River Stour.

HORIZONTAL SS FLAT WELDED TO VERTICAL SS FLAT (1.4401 (316) REFER TO SPECIFICATION SECTION L3) RECESSED PIGNOSED BOLTS

40MM THICK SEASONED ENGLISH OAK GROOVED EDGE DECKING

CAST STAINLESS STEEL BALUSTRADE ARM (PEENED) (1.4401(316) REFER TO SPECIFICATION SECTION L3)

'HALFEN TYPE FIXING'

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5.48 A working drawing of the balustrade, by Michael Stacey Architects. This safety system is a combination of stainless-steel castings, stainless-steel wires and two bespoke aluminium extrusions.

5.49 Local people at the opening of Ballingdon Bridge, 18 July 2003.

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E

2 No. TENSION BARS SS M40 BOLTS WITH PIGNOSED'FEATURE' 1 No. COMPRESSION STUD SS FIXING PLATE CAST WITHBALUSTRADE ARM

A

SECTION A-A Through longest balustrade Arm at Midspan

EXTRUDED STAINLESS STEEL EDGE MEMBER FIXED TO BALUSTRADE ARM WITH 1No. SS M16 ALLEN HEAD BOLT

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5.50 Ballingdon Bridge, set in the SSSI of the River Stour. In a food, the bridge will hold back the foodwaters, saving houses downstream.

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CHAPTER 6

Performative Façades This chapter focuses on the role of aluminium in creating or supporting performative façades. The importance of a holistic and collaborative approach to the design and realisation of architecture in the 21st century remains a key theme throughout. The frst decade of the 21st century witnessed the rapid adoption of parametrically designed architecture and building façades.

6.1 (opposite) 30 St Mary Axe, by Foster + Partners with engineers Arup, completed in 2004, viewed from Leadenhall Street in the City of London, past St Andrew Undershaft.

30 St Mary Axe, London, is a 180m-tall, environmentally progressive ofce building designed by Foster + Partners and completed in 2004. It is one of the frst parametrically designed tall buildings in the world, based on geometry generated by seven tangents rotated through 360°, which results in a gently tapering aerodynamic form. Characteristically of Norman Foster, it is also an excellent example of investment in early and experimental design. The development of the parametric modelling benefted from the extended planning approval process on a ‘controversial’ site: the Baltic Exchange was the location of an IRA bomb on 10 April 1992. Although parametrically designed, based on seven carefully chosen tangents, 30 St Mary Axe is a conventionally layered construction, from the planning envelope within which the building could be constructed that is just outside the aluminium curtain walling, to the diagrid steel

6.2 Foster + Partners defned the geometry of 30 St Mary Axe by parametrically varying seven tangents.

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structure. It is clad in 5,500 glass panels, which vary dimensionally at each level. One of the aspects of 30 St Mary Axe (also known as the Gherkin) that remains remarkable is that the doubly curved geometry is delivered by a combination of triangular and diamondshaped panels, thus greatly reducing the cutting and framing required. This is a double façade comprising an outer double-glazed unit supported by an aluminium curtain walling, a ventilated cavity incorporating solar control blinds and an inner layer of single glazing. Foster + Partners designed the cavity to act ‘as bufer zones to reduce the need for additional heating and cooling’ and the bufer zones ‘are ventilated by exhaust air which is drawn from the ofces’.1 The distinctive spiral bands of grey glazing articulate the internal atria.

6.3 (opposite) The internal atria of 30 St Mary Axe are defned by the dark grey tinted glass zones in the façade, by Foster + Partners.

The University of Pennsylvania’s Melvin J and Claire Levine Hall, in Philadelphia, by KieranTimberlake, 2003, establishes a forward-looking character for the School of Engineering and Applied Science, while remaining sensitive to its historic context.2 Located on a former parking lot, Levine Hall stiches together two existing university buildings – Towne Building, by Cope and Stewardson, 1906, and the Graduate Research Wing, by Geddes Brecher Qualls Cunningham, 1967 – forming a central courtyard and common entrance for the School of Engineering and Applied Science, via Chancellor Walk, of 34th Street. The building comprises six foors, with the possibility of adding a seventh foor, housing ofces, laboratories and

6.4 Melvin J and Claire Levine Hall, Philadelphia, by KieranTimberlake, 2003; the frst use of an active double façade in the USA.

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meeting space for the Department of Computer and Information Science and a 150-seat auditorium. Levine Hall was designed by KieranTimberlake to maximise long-term fexibility and has a 4.27m foor-to-ceiling height. The footprint and massing respond to adjacent buildings, with particular attention to scale and fenestration. The building is articulated as a glazed pavilion, presenting luminous, transparent façades to the campus.3 This strategy allows daylight to be maximised on a dense, urban site, and provides visual interconnections between the life of the campus and life within the building. The west and main façade of Levine Hall incorporates a pressure-equalised and ventilated aluminium curtain wall system, which provides maximum views and daylighting with substantial energy efciency and interior comfort. Key components of the ventilated system are a double-glazed, pressure-equalised unit on the exterior, a single-glazed unit on the interior, with air continuously ventilated through the cavity between them. Blinds are housed in the ventilated cavity and are fully adjustable, allowing for shading or visibility. Housed in the cavity, the blinds should require very little maintenance. 6.5 (left) KieranTimberlake’s section through the aluminium-framed active double façade of Levine Hall.

6.6 (right) Permasteelisa installing the unitised double façade of Levine Hall.

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This active double wall was developed by a close collaboration between KieranTimberlake and façade specialists Permasteelisa and delivered as bespoke, unitised, factory-glazed, aluminiumframed units to rapidly and precisely deliver the façade. It is the frst use of an active double-glass façade in the USA. KieranTimberlake’s design intent has been achieved: ‘The use of ventilated curtain walling technology allows the use of large expanses of glazed exterior wall surfaces, providing abundant natural light and views, while providing interior comfort and modest energy consumption.’4

6.7 Levine Hall, viewed from Chancellor Walk.

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240 Blackfriars Road, London, by Allford Hall Monaghan Morris, completed in 2014, is a crisp and elegant contribution to the central London skyline and cityscape. Haydn Thomas, of Allford Hall Monaghan Morris (AHMM), describes how ‘240 Blackfriars Road defnes the skyline at a pivotal junction of road, rail and river at the south end of Blackfriars Bridge’.5 The 20-storey ofce tower provides over 21,132m2 of high-quality workspace above groundlevel retail units and a new public realm, together with 10 residential units in the adjoining brick-clad six-storey volume, at a capital cost of £70 million. This mixed-use scheme replaced a collection of low-rise, unprepossessing and dilapidated light industry and ofce premises on the Blackfriars Road.

6.8 240 Blackfriars Road, London, by Allford Hall Monaghan Morris, 2014, viewed looking south down Blackfriars Road.

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The design development of the crisp crystalline form of 240 Blackfriars Road began for AHMM in 2005. The plan form is very efcient, with the servant spaces of lifts, service voids, escape stairs and washrooms all located as a single block, occupying most of the east façade. Above the central entrance atrium, the ofces form generous spaces that can be open plan from the south to the north façades. The building is topped by a triple-height ‘sky-room’, behind which is the plant room.6 AHMM inventively resolved one of the recurrent dilemmas in the design of tall buildings – where to house the plant room. Mechanically, the efcient location is the top of the building, making the access to free air for exhausts and fues very simple and direct. Yet typically this is the most attractive and valuable space created in this form of architecture. AHMM describe the form as being ‘inspired by the strength of natural geological forms’7 and cut to minimise the impact to Ludgate House and orientate the building towards the river and city. The top of 240 Blackfriars Road is cut again to create a triple-height ‘sky-room’, with a plant room on the eastern and southern part of the plan, topped with a 9kW photovoltaic array comprising 40 panels. 240 Blackfriars Road is predominately a concrete-framed structure that utilises post-tension concrete slabs, only 275mm thick, combined with low-profle raised foor, and chilled ceiling with LED lights, in a 350mm service zone to achieve an efcient foor-to-foor height, which created an additional one and half foors when compared to a conventional steel frame. The design and coordination of the project was delivered by the use of a building information model (BIM) from RIBA Plan of Work Stage 4. This ofce building is completely clad in high-performance, argon-flled, double-glazed units, predominately in the form of silicone-bonded unitised aluminium curtain walling, providing a fush outer surface and crisply detailed edges – delivering the desired crystalline form. The unitised aluminium curtain walling is set out on 1.5m grid. Solar control is achieved via ‘pinstripe’ fritting and a solar control layer on surface three. On the sloping north façade, which is visible from the Thames, the fritting is omitted to maximise daylight and views of the city. Throughout the building envelope, only glass-to-glass junctions are used, contributing to the tectonic crispness of the project. With the exception of the corner-to-corner junctions arising from the project’s crystalline form, here black anodised aluminium extrusions were introduced to provide edge protection while retaining the sharpness of form and detail. The aluminium extrusions of the curtain walling and roof glazing are the largely unseen ‘helping hands’ of the building envelope. The air leakage rate through the façades was limited to 1.5M3/m2/hr. This, combined with a Ucw-value of 1.4W/m2K, efective solar control and other measures, created a good energy balance in the building fabric of 240 Blackfriars Road. The building achieved a 28% improvement on England and Wales Building Regulation Part L 2010 and an Excellent rating under BREEAM 2011.8 The building envelope was fabricated and installed by Scheldebouw, who worked closely with AHMM via a process of mock-ups and prototypes

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6.9 240 Blackfriars Road, site plan.

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6.10 Detail of 240 Blackfriars Road showing the highperformance, argon-flled, double-glazed units and silicone-bonded unitised aluminium curtain walling.

in its factory in the Netherlands. This included the design development of a discreet fail-safe mechanical restraint system for the sloping silicone-bonded aluminium-framed curtain walling. 240 Blackfriars Road is an excellent example of a 21st-century project for a commercial client. The provision of daylight yet controlling solar heat gains in buildings signifcantly reduces the day-to-day need for primary energy, when designed on a regional and site-specifc basis, avoiding overheating and glare from solar gains while ensuring the maximum use of daylight, including benefcial use of solar gains during heating seasons. Solar shading is at its most efective when outside the glazing and therefore the durability of aluminium is of vital importance. The Sculpture Building and School of Art Gallery, by KieranTimberlake, 2007, seeks to forge a new relationship between the city of Connecticut and Yale University. KieranTimberlake’s design is a considered response to the urban conditions found on this brownfeld site: ‘While much of the campus clusters about cloistered quadrangles that exclude the city, the new sculpture building and art gallery sought to invert those historic patterns and invite the city into and through the site.’9 The design of the project extends the university art district westwards, engaging the city with pedestrian routes and active street frontages. The buildings are a mixture of uses, encompassing an art gallery, studios, classrooms, workshops, retail space and parking. The architect addressed three key issues, using a holistic approach to the designing of the project: light, air quality and energy. KieranTimberlake sought to balance maximising daylight with energy efciency in an all-glazed façade that incorporates solar shading, triple-glazed low-emissivity (low-e) clear vision panels, openable windows and translucent spandrel panels. 159

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6.11 KieranTimberlake’s interpretation of Gothic tracery in a high-performance façade, creating context and amenity with panache for the Yale University Sculpture Building, New Haven, Connecticut, 2007.

6.12 (opposite) The bespoke extruded aluminium solar shading of the south façade and the Kalwall panels of the west façade of the Yale University Sculpture Building.

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The 4.3m-high studio spaces are washed with daylight. Even the translucent spandrel panels admit 20% daylight. The architect’s commitment to daylighting has been fully integrated with the building lighting design through the installation of daylight dimming. Analysis of the climate of New Haven indicated a strong seasonal variation, with signifcant heating required during the winter and cooling in the summer. Based on sun path analysis, KieranTimberlake chose to orient the Sculpture Building north–south, minimising eastern exposure and almost eliminating western exposure. Observing the lack of overshadowing from adjacent buildings, the architect determined that horizontal shading was needed along the southern and eastern façades. In New Haven, the summer sun is very high in the sky at midday and reaches from northeast in the morning to the northwest in the evening. The winter sun is only a 25.5° at midday and travels from southeast to southwest. KieranTimberlake designed and developed bespoke extruded aluminium solar shading, in collaboration with Schüco, to block summer sun and admit winter sun using the midday sun angle of 25.5° as the design cut-of. The extruded aluminium curtain walling and solar shading are fnished with a three-coat PVDF (polyvinyl fuoride) wet-applied paint system.

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The overall curtain walling assembly was designed as a collaboration between KieranTimberlake, Schüco and Kalwall. The predominately south-facing glazing enables the building to receive benefcial solar gain during the winter months, thus reducing the energy demands of the heating season. In turn, the solar shading cuts out the risk of overheating in the summer months. The spandrel panels comprise a low-e double-glazed unit, an air cavity and a translucent Kalwall panel flled with aerogel. It was the frst project in Connecticut to achieve LEED Platinum.10 Kalwall is a composite panel with glass-reinforced polymer (GRP) skins and an internal extruded aluminium structure with visual antecedence in Japanese shoji screens. It was invented in 1955 by Robert R Keller.11 Kalwall is now available with thermally broken aluminium extrusions and flled with translucent aerogel insulation, providing U-values as low as 0.28W/m2K. Aerogel was invented by Samuel S Kistler in 1931. It is such an efcient insulator as it traps air on a molecular basis. 6.13 KieranTimberlake’s detail of the south façade of the Yale University Sculpture Building, showing the key solar angles for the design of the louvres.

6.14 KieranTimberlake’s psychrometric chart of the comfort zone for the Yale University Sculpture Building created by the cooling potential of the available natural ventilation.

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6.16 Solar shading plan detail of the south and east façades of the Yale University Sculpture Building, shown at 1:25. 1. Aluminium curtain wall mullion/transom 2. 44mm triple-glazed low-e IGU (insulated glass units) 3. 25mm double-glazed low-e IGU 4. Aerogel-flled translucent fbreglass-faced Kalwall 5. Triple-glazed, inwardopening casement window 6. Steel bent plate, U-anchor welded to pour stop 7. Aluminium bracket and sunshade support arm 8. Aluminium sunshade blade

6.15 The Kalwall panel module used on the west façade of the Yale Sculpture Building: 1. Translucent glass-reinforced polymer (GRP) exterior face 2. Structural grid core (aluminium extrusion or thermally broken aluminium extrusions) 3. Translucent insulation (TI) thermal packages, including aerogel

9. Aluminium tube at sunshade blades only 10. Press-brake formed aluminium panel closure 11. Hydronic fn-tube heating assembly 12. Concrete slab on metal deck 13. Steel wide fange column 14. Steel wide fange beam 15. Roller shade

4. Translucent GRP interior face

6.17 Solar shading section detail of the Yale University Sculpture Building, shown at 1:25.

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6.18 The new Everyman Theatre, Hope Street, Liverpool, by Haworth Tompkins, 2013.

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The Everyman Theatre, Liverpool, opened in 1964 in the reused shell of a 19th-century chapel, Hope Hall, that had previously been used as a cinema. It became a very successful ‘theatre of the people’, nurturing both acting and writing talents.12 The author studied architecture in Liverpool in the 1970s and early 1980s and was lucky enough to enjoy many excellent productions and ad hoc performances by Liverpool poets in the basement Bistro. By the Millennium, it was clear that the theatre needed to be renewed. Architect Haworth

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Tompkins ‘expertly met a difcult challenge: that of creating an entirely new and sustainable building, whilst retaining and revitalising the best-loved features of its predecessor’,13 creating ‘a new building with a striking exterior and elegant interior, all with exceptional attention to detail and sustainability credentials’.14 The theatre is adjacent to Liverpool’s Catholic Metropolitan Cathedral, designed by Sir Frederick Gibberd and completed in 1967, and it is in the context of listed 18th- and 19th-century buildings. Sir Giles Gilbert Scott’s Anglican Cathedral, completed in 1978, stands at the opposite end of Hope Street. The new Everyman Theatre comprises a 400-seat adaptable auditorium, a studio for youth, education and community activities, a large rehearsal room, public foyers, a cafe, a bar, a bistro, a writers’ space and administrative ofces. Haworth Tompkins used large 1:25 physical models to study and resolve the public spaces of the theatre. The ‘building makes use of the complex and constrained site geometry by arranging the public spaces around a series of half levels, establishing a continuous winding promenade from street to auditorium. Foyers and catering spaces are arranged on three levels, including a new bistro, culminating in a long piano nobile foyer overlooking the street.’15 The special quality of the foyer space and community room are reminiscent of the social spaces designed by Sigurd Lewerentz in his later churches, including St Peter’s in Klippan, Sweden (1965). Natural ventilation is provided for all the main performance and workspaces. For most of the summer and during autumn and spring, outdoor air is supplied to the main auditorium without the need for mechanical assistance. This was carefully studied using computational fuid dynamics undertaken with services engineers Watermans. The theatre is very well built by Gilbert-Ash. The capital cost of the Everyman was £13.4 million.

6.19 The life-sized portraits of the people of Liverpool are waterjet cut into the 8mm dark bronze anodised aluminium sunshades.

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6.20 Solar shading detail elevation, section and plan for the Everyman Theatre.

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3. Aluminium tab fxed between steel tabs 4. Extruded aluminium frame, dark bronze anodised 5. 8mm aluminium shutter panel with pivot bearing

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6. Shutter panel set in 90° position 7. Aluminium rainscreen panels, dark bronze anodised

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8. Single-membrane roofng on rigid insulation 9. Pivot arm of lower bracket engages via spring pin with hoop 10. Sliding and tilt-and-turn windows with aluminium frame, dark bronze anodised 11. Bottom-hung windows with aluminium frame, dark bronze anodised 12. Boardmarked concrete column and downstand beam beyond

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13. Bottom restraining bracket, dark bronze anodised aluminium 14. Painted steel channels 15. Aluminium-framed sliding doors

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Haworth Tompkins observed, ‘Having minimised the space and material requirements of the project, the fabric was designed to achieve a BREEAM Excellent rating, unusual for an urban theatre building.’16 From the outset, Haworth Tompkins conceived the Everyman as an exemplar of sustainable good practice. The interior is characterised by the use of reclaimed 19th-century bricks (the fabric of the original chapel) and exposed concrete, providing thermal mass and cultural continuity, combined with a very Scouse sense of glamour – a good night out in a people’s palace. The main auditorium is mimetic of this space in the 1970s, almost a double take, yet it is adaptable and fully accessible for mobility-impaired performers and audience members alike – a theatre for everyone. 166

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The west-facing Hope Street façade is primarily composed of 105 moveable aluminium solar shades, each carrying a life-sized waterjet-cut portrait of a contemporary Liverpool resident. The only criterion for the selection was each citizen was not famous. They all received a ticket for life at the theatre. The architect worked with local photographer Dan Kenyon to engage ‘every section of the city’s community in a series of public events, so that the completed building can be read as a collective family snapshot of the population in all its diversity’.17 The 8mm dark bronze anodised and waterjet-cut aluminium solar screens were organised by specialist subcontractors James and Taylor. The dark bronze anodising is 25µm thick in accordance with BS 3987:1991 for external applications. This façade is a key part of Haworth Tompkins’ environmental strategy for the theatre, alongside the exposed concrete and bricks of the interior providing thermal mass: ‘The orientation and fenestration design optimises solar response – the entire west façade is designed as a large screen of moveable sunshades.’18 Each aluminium panel has a central pivot and is held in place top and bottom by curved aluminium fats with holes at regular centres, reminiscent of a sextant. On the frst foor of the theatre, the bar spills out onto a balcony overlooking Hope Street, thus on summer evenings the one–to-one portraits are underscored by the theatregoers of Liverpool.

6.21 The Everyman Theatre combines glamour and deep roots in place and humanity – it is a fun palace, a realisation of the dreams of Joan Crawford and Cedric Price in the early 1960s.

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The British Airways i360, in Brighton, by Marks Barfeld Architects, launched its frst ‘fight’ on 4 August 2016. Designed by Julia Barfeld and David Marks, architects of the London Eye (2000), it is a vertical pier located at the entrance to Brighton’s old West Pier, which opened in 1866, fell into disrepair in 1975, and burnt down in 2003.19 It follows on from the London Eye, which was designed as a temporary celebration of the Millennium. The London Eye is a 132m-high Ferris wheel with 32 pods, and is now a permanent landmark on London’s

6.22 The British Airways i360, Brighton, by Marks Barfeld Architects, 2016, viewed from the foreshore.

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skyline, visited by more than 4 million people annually. Although the i360 shares design DNA with the London Eye, it has been tailored to work successfully as a regional attraction within a seaside city with around 10 million annual tourists. The i360 is a vertical cable car with a single pod that has a capacity of 200 people. It has been designed as a venue, a destination and a symbol of renewal. The i360 tower is 162.43m high, measured from the Ordnance Survey Datum, and only 3.9m in diameter. It is ofcially the slimmest tall tower in the world, with a width-to-height aspect ratio of 1 to 40.20 To reduce vortex shedding on this elegantly slender tower, Marks Barfeld Architects clad it in expanded anodised aluminium. During a ‘fight’ in the i360, up to 200 people rise 138m above the Brighton seaside in a glazed doughnut-like pod. This description does not do justice to the elegance of the pod, designed by the architect in collaboration with POMA. The construction cost of the i360 on completion was £37 million.21 To deliver the i360, Marks Barfeld Architects in essence reassembled the core team from the London Eye: Hollandia for the prefabricated steelwork and POMA for the pod. The structure of the tower is formed from prefabricated high-grade steel formed into tubular sections known as cans, supported by in-situ concrete foundations. All the cans were fully prepared to receive the expanded aluminium cladding, with cladding rails already in place. The top two cans were installed fully clad. The tower was then clad from the top down.

6.23 Marks Barfeld Architects’ comparative analysis of the aspect ratio of key tall buildings in London with Brighton’s i360.

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The single pod is counterbalanced by a weight inside the tower, which is slightly lighter than the pod itself. A cable draws down the counterweight and the pod rises. On the return journey to the ground, 50% of the energy used is harvested by regenerative motors. With the cable passing over a pulley wheel at the top, the i360 is a distant echo of the coalmine pitheads that were once commonplace in many parts of the British landscape, until the 1980s.

6.24 Inside the i360 pod during construction, photographed April 2016.

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The glass pod, fabricated by POMA in France, has the feel of a Dan Dare spaceship or fying saucer: an elegant observation deck, which one can walk around and enjoy the full 360° panorama. At 18m in diameter, the geometry of the pod is an oblate ellipsoid, an ellipse rotated through 360° about its minor access, with a cylindrical hole through its centre. The pod is supported by a red painted steel chassis comprising four masts, a large ring beam supporting the foor structure of the pod and a smaller I-section top ring beam, which picks up the internal structure of the pod. Each of the four masts is linked to the counterweight inside the tower by a high-tensile steel cable, located behind the expanded anodised aluminium cladding. The masts are equipped with a set of spring-loaded guide wheels that run on the steel structure of the tower. The pod is structured and clad in 24 radial segments.

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The lower ring beam picks up the cantilevered steel foor structure, the glass is supported by 48 polyester powder-coated steel sections, which span from the foor to the upper ring beam. The foor void houses all the heating, ventilation and air conditioning (HVAC), audiovisual and safety systems of the pod, powered via two bus bars on the tower next to the east and west guide ways.

6.25 An inaugural fight of the i360, in August 2016.

The pod is glazed in doubly curved and double-laminated double glazing. The outer surface of the glass incorporates a permanent self-cleaning treatment (the pods of the London Eye are only single glazed). The double-glazed units, which comprise a laminated outer pane, a sealed air gap and laminated inner pane, were produced in Italy by Sunglass, using bespoke and patented moulds. As the glass is heated in the moulding process, it can be considered to be heat strengthened, but not toughened. However, the size and details of each pane had to be predetermined, as it is not possible to cut or drill this type of glass after moulding. The 24 glazed segments of the soft are fully mirrored on surface two. The tower is clad in 5mm-thick expanded aluminium, which is fnished in 25µm silver anodising in accordance with BS 3987:1991. The aluminium sheet is expanded with the ‘Bilbao’ pattern from a bespoke aluminium grade 151EX sheet, which combines good ductility for expanding and anodises well. This was supplied to the Expanded Metal Company by 171

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6.26 Ian Crockford, Project Leader for Marks Barfeld Architects, described ‘the spectacular iris-like efect of watching the pod ascend the tower from the entrance deck level, created by this curved mirrored surface’.22

James and Taylor, who coordinated the cladding, and installed by Hollandia. The expanded aluminium cladding panels were roll formed to the desired radius and are 2m high with a radial panel width of 3.2m. The anodised aluminium panels, with periodic cleaning, should prove durable for the complete design life of this project, despite the marine location. Although each large-format expanded sheet is light enough to be readily carried by four people, weighing approximately 10kg/m2, almost 20 tonnes of aluminium were used to clad the i360, covering an area of just over 2,000m2.23 One advantage of working with expanded metal to create façade panels is that there are no ofcuts produced when processing the sheet material, unlike perforating sheet metal with a punch tool. The fxing detail of this cladding is revealed at the base of the tower in Figure 6.31. The anodised expanded aluminium cladding is supported by hollow T-section aluminium extrusions, which incorporate a fxing channel. These cladding rails are fxed back to the steel tower via rowlock-like u-shaped steel fabrications, which are bolted to cleats welded to the tower. The potential for bimetallic corrosion, between the aluminium cladding rail and the steel subassembly, is avoided by polymeric isolators.

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6.27 One of the anodised expanded aluminium sheets for the i360, during manufacture by Expanded Metal Company in Hartlepool.

6.28 Each sheet of expanded aluminium for the i360 is light enough to be easily carried by four people.

6.29 Vortex shedding caused by a circular object subjected to wind fow like the i360 tower. (The green dots represent the wind passing the top side (in the plan drawing) of a circular tower and the purple dots represent the wind passing the underside. The turbulence generated by the wind mixes as it swirls in vortexes on the leeward side of the tower.)

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All structures have a natural vibration frequency, which is a product of the slenderness ratio and the stifness of the structure. The i360 tower has three modes of oscillation, which are the three lowest natural frequencies of vibration this tower will respond to. The starting point to eliminate the risk of wind-induced vibration was the specifcation of the expanded aluminium cladding to minimise vortex shedding. Ian Crockford, Project Leader for Marks Barfeld Architects, explained, ‘The expanded aluminium cladding is a key part of the damping strategy; the surface roughness and air fowing through the cladding disrupts the wind speed, thus minimising the vortex shedding on the leeside.’24 The design team did not consider it necessary to wind-tunnel test the cladding, based on the expert advice of Max Irvine from Sydney, Australia, on the minimisation of vibration risks on the extremely slender tower. The tower is also ftted with three types of liquid-flled dampers, each tuned to one of the vibration modes. The dampers were fabricated in New South Wales and were ftted in the steel cans in the Netherlands and the pod in France. In total, more than 50 dampers have been ftted to the tower, with a further eight located in the pod. Aluminium was selected for the cladding in competition with grade 316 stainless steel. The role of the cladding is described by Crockford as ‘a transparent veil combined with its performative function’.25 The expanded panels, with their many edges, and the coastal location convinced Marks Barfeld Architects that anodised aluminium was the better option. Knowing that the cladding will need to be washed on a regular basis, the tower is crowned by a circular rail to support abseilers. The gaps for the four masts of the pod, where it climbs the tower, delineate the anodised expanded aluminium cladding and further emphasise the slenderness of the tower. The anodised expanded aluminium cladding creates a gentle visual softness to this monumental tower.

6.30 (opposite) The expanded aluminium minimises the vortex shedding and thus limits the possibility of vibration in the i360 tower.

6.31 The anodised expanded aluminium cladding at the base of the tower.

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7.1 The Voyager spacecrafts, made of 92% aluminium and silicone, are the most distant artefacts produced by humankind.

CHAPTER 7

Economical, Powerful and Sympathetic Aluminium ofers an economy of means, afordability and, in the hands of a creative design team, it can be powerful, expressive and sympathetic.

Economical The afordability of aluminium as a means of providing long-term durability in contemporary architecture is of vital importance. The high strength-to-weight ratio of aluminium alloys is of signifcant importance to the design of roofng and cladding systems – with benefts such as minimising transport cost, facilitating mechanical handling or the potential of installation by hand. It is noticeable in this chapter that most of the projects are of a large scale. However, this technology remains accessible to every architect, whatever the scale of his or her project.

7.2 Northeast façade of Stratford Market Depot, London, by WilkinsonEyre, 1996.

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7.3 The primary elements of Stratford Jubilee Line station, London, by WilkinsonEyre, 1999.

7.4 Northwest elevation of Stratford Jubilee Line station.

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Stratford Market Depot, the train shed for the eastern end of the Jubilee Line extension, completed in 1996, was the key breakthrough project for WilkinsonEyre. It fulflled the intellectual promise shown in Chris Wilkinson’s book Supersheds, published in 1991.1 The depot is a supershed, 100m wide and 190m long, which forms a parallelogram in plan, in part to avoid the archaeological remains of Straford Abbey at the southern end of the site. It accommodates 11 train lines: three lines are for the heavy lifting shop, the central fve lines are for general maintenance, and three lines are for cleaning. Ancillary accommodation is arranged in three blocks to the western side of the depot, with the control building articulated on the opposite corner. The steel structure is a diagrid of trusses 9m long and 2.4m deep. The two lines of trusses are at 60°, generating parallelogram bays. This diagrid is picked up by tree-like columns in bays of 18m by 40m, creating an 8m clear height above the track level. The standing-seam roof is clad in Kalzip, dual-alloy, mill-fnish aluminium sheets that are continuous and gently curved, thus avoiding internal gutters. This train shed is generously daylit by roof lights throughout, which run broadly east–west in response to the structural grid below. The specialist installer of the aluminium standing-seam roof was Prater Ltd. The depot, completed in April 1996, was conceived and delivered as a high-quality work of contemporary architecture, in keeping with all of the stations of the Jubilee Line. Stratford Jubilee Line station, WilkinsonEyre’s next project, is also clad with an aluminium seam roof. The design of the Jubilee Line extension was led by Roland Paoletti and it opened to the public in 1999. The excellence of this public architecture and infrastructure was a key factor in London winning the 2012 Olympic bid in 2005. Stratford Jubilee Line station served as a major gateway during the 2012 London Olympics.

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Among the watchwords for the design and procurement of the London 2012 Olympics were responsible sourcing and legacy. At one stage it appeared that the Olympic Delivery Authority (ODA) did not understand the environmental credentials of aluminium and that it can be readily sourced responsibly, and that it can be part of a reuse strategy or recycled. They also appeared not to appreciate the long-term durability aluminium ofers in a legacy mode of continued use. The UK aluminium industry worked hard to secure the role of this light metal in the delivery of 2012 Olympics.

7.5 South façade of Stratford Jubilee Line station.

The 2012 Olympic Velodrome, in London, designed by Hopkins Architects and completed in 2011, was won in competition with Expedition Engineering. It is probably the best example of a venue tuned for Olympic success, with nine World Records and 11 Olympic Records being achieved there. Its future use as the Lea Valley Velopark was in place before the Olympics. Richard Arnold, the ODA project sponsor of the Velodrome, explained in 2007, following Hopkins Architects’ appointment, ‘We spent the frst four months focusing on the masterplan of the VeloPark, during which, while the facilities stayed the same, we actually increased the overall site area over that identifed in the brief.’2 Following extensive consultation with future user groups and with the legacy secure, only then did Hopkins Architects, with fellow consultants, focus on the design of the Velodrome itself. The elegant simplicity of Hopkins Architects’ Velodrome design delivered a world-class arena seating 6,000 spectators for a capital cost of £90 million. It was delivered on budget and ahead of programme, assembled from February 2009 to January 2011. Following the Olympics, the Velodrome and its site were converted into a velopark, at a cost of only £4 million. In contrast, the main Olympic Stadium, designed by Populous, was converted to a soccer stadium as a retroft. The stadium cost £486 million in 2012,3 with the cost of the conversion a further £272 million, despite the retroft being by the same architect. 179

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7.6 The 2012 Olympic Velodrome, London, by Hopkins Architects, 2011, viewed across the Queen Elizabeth Park.

Hopkins Architects worked to ODA sustainability and material targets; through careful consideration and integration of the architecture, structure and building services, the design has met or exceeded these requirements. It was delivered via collaboration within the design team and with the main contractor, ISG, the specialist subcontractors and the complete supply chain. A non-adversarial partnering form of contract was used – a New Engineering Contract: Option 3. Mike Taylor, a partner at Hopkins Architects, explained, ‘Whereas the design of the bicycle has evolved through numerous evolutionary steps, we had one hit at the Velodrome,’4 noting that it ‘could not have been designed and built without the latest 3D computer modelling techniques’.5 The design process began with sketches: ‘Perhaps surprisingly for such a complex building, nearly every aspect started life as a sketch by hand on paper.’6 Observing the importance of cross-disciplinary collaboration in achieving such a highly integrated design, Taylor stated the need to retain a clear ‘philosophical and aesthetic vision’ of the project.7 Revealing his clarity of vision during the design process, he said, ‘The Velodrome sets out to reconcile ambitious engineering and technology with more architectural concerns of form, proportion and composition.’8 Chris Wise, founder of Expedition Engineering, described how a ‘striking, doubly curved roof shape evolved as the form which would best answer the stadium’s needs. The saddle-shaped roof “shrink wraps” the building around the track, minimising the interior volume and in turn reducing heating and cooling requirements.’9 The cable net comprises pairs of 36mm-diameter spiral strand steel cable set out primarily on a 3.6m grid. The cables running north–south resist gravity and have their high points on the ring truss; those running east–west resist wind uplift in this lightweight roof connected to the roof truss at its low sweep. In contrast, the successful Ghent Velodrome, designed by MJ Trefois and completed in 1964, uses a 67m clear span aluminium roof structure.10 18 0

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7.7 The 2012 Olympic Park site plan. 1. Velodrome 2. BMx Track 3. Olympic Stadium 4. Aquatics Centre 5. Athletes’ Village

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7.8 Inside the 2012 Olympic Velodrome, photographed in January 2013, during the minor works to prepare it for longterm community use.

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7.9 The 2012 Olympic Velodrome, upper tier plan. 1. Timing/scoring zone 2. Track 3. Safety zone 4. Infeld 5. Legacy road circuit 6. BMx track

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7.10 The 2012 Olympic Velodrome, longitudinal section.

Timber cassette panels were placed onto the cable net structure of the 2012 Olympic Velodrome via ‘receiver brackets’, with a temporary waterproof layer, on the nominal 3.6m grid. There are about 1,000 standard panels and approximately 100 non-standard. All are carefully detailed to allow for movement in the cable net and to constrain this in particular directions. A vapour check layer was laid onto the temporary waterproof layer, followed by 300mm of insulation and then a Kalzip, dual-alloy, mill-fnish, aluminium standing-seam roof. The thermally efcient Kalzip clip fxing detail for the standing-seam roof is attached to the timber cassette panels. The roll-formed aluminium roof panels are up to 130m long, in single sheets, and the standing seams run east–west. The specialist installer of the aluminium standing-seam roof was Prater Ltd.11 With a roof area of 14,000m2, the case for design optimisation, including the use of prototypes and mock-ups, is very clear.

7.11 Detail of the cable net structural node and roof assembly of the 2012 Olympic Velodrome. 1. Aluminium standing-seam roof 2. 300mm insulation providing overall U-value of 0.15W/ m2K 3. Vapour barrier 4. Timber roof cassette with birch-faced plywood soft incorporating steel corner brackets 5. Fabricated steel powder-coated receiver brackets with PTFE (polytetrafuoroethylene) coating to underside 6. Fabricated steel powdercoated connection plate with PTFE coating to top; combination of fxed, slotted and oversized holes varies with location 7. Steel powder-coated washers 8. Nut 9. Galvanised forged-steel top cable clamp 10. Galvanised forged-steel middle cable clamp with paired 36mm-diameter cables at 120mm centres 11. Galvanised forged-steel bottom cable clamp 12. Bolt through cable clamp assembly 13. Galvanised forged-steel cover plate with connection for lighting containment

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7.12 The steel cable net, tensioned and ready to receive the timber cassette panels for the 2012 Olympic Velodrome.

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The roof steelwork is only 30kg/m2, less than half the weight of the roof structure of the Beijing 2008 Velodrome. The use of a cable net structure saved over £2 million pounds and resulted in a three-month-shorter site time. The cable net, weighing only 100 tonnes, uses 27% less steel by mass when compared to steel arches. It is an excellent example of structural design optimisation, a case of achieving more with less – with the lightweight aluminium roof playing its role in a minimal material strategy. Overall, including the steel cable net, timber cassette panels, insulation and aluminium standing-seam sheeting, the roof of the Velodrome weighs 70kg/m2.

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The control of the internal comfort condition of the Velodrome was also carefully considered and integrated into the architectural intent from the outset of the design. Klaus Bode, of environmental design consultants BDSP, considered: One of the key challenges regarding the environmental performance of the Velodrome was to enable the fastest track-level conditions, while keeping spectators comfortable throughout the year and in diferent types of events, from the Games to school sessions. Passive and active systems had to allow for the high temperature (about 26°) required by the cyclists to achieve record-breaking times.12 7.13 Roof edge detail of the 2012 Olympic Velodrome. 1. Anodised aluminium bullnose capping 2. Gutter 3. Single-ply roofng with 60mm-high batten roll to channel rain into gutter 4. Pin-jointed bridging joists cut on site provide make-up strip and allow movement between cable net system and rigid ring beam 5. Timber cassette spanning between inner and outer ring beams 6. Single-pin connection between cables and brackets to ring beam

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7.14 Commemorative Royal Mail First Day Cover in honour of the Men’s Team Sprint Gold Medals at the 2012 Olympics.

Daylight is used to provide an uplifting environment while minimising energy consumption. The roofights use self-cleaning glass with white difusing PVB (polyvinyl butyral) interlayers in the inner leaf of the double-glazed units, thus the roof does not have cleaning accesses safety systems designed in, even in the context of UK Construction Design and Management Regulations. The total embodied CO2 of the structural elements of the Velodrome is 7,400 tonnes, less than 1,250kg of CO2 per seat.13 The Velodrome’s predicted reduction in carbon emissions is 31%, more than double the ODA target of 15% and better than any other 2012 venue. Although this is aided by the combined heat and power unit, providing district heating to all of the Olympic venues, it is achieved by a fabric-frst strategy with no on-site applied renewables. In essence, the design achieves more with less, demonstrating that environmentally sound architecture can be achieved by integrated design and careful material selection within tight timescales and without costing more. Attention to material selection and the unity of design intent and detail, in Nicolas Serota’s opinion, ‘ensure the building is easy to maintain and will look as good in 20 years as it does today’. It ‘promises to enhance the experience of every user and visitor to the building for generations to come’.14 This is the very essence of sustainability in the built environment. A well-informed brief, design excellence and high-quality execution are the cornerstones of sustainability. Yet the needs for such highly skilled processes are hardly mentioned in the conventional discourse of big data and technocratic solutions. 7.15 (opposite) Externally, only three materials articulate the Velodrome: glass, aluminium and western red cedar.

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The 2012 Olympic Aquatics Centre, in London, by Zaha Hadid Architects, has two 50m pools, a competition pool and a warm-up or training pool, with a 25m diving pool – all achieved at a capital cost of £269 million and completed in 2011, ready for the Games.15 The atmosphere was electric during the 2012 Olympic and Paralympic swimming events. The form of the Aquatics Centre, in the words of the architect, is ‘a concept inspired by the fuid geometry of water in motion’.16 To meet the audience capacity set out by the Olympic Committee, what became known as the ‘saddlebags’ were added to either side of the competition pools. This increased the seating capacity to 17,500 spectators – and the sightlines were surprisingly good. The saddlebags were removed after the Olympics and were replaced by curtain walling. Today, the Aquatics Centre can accommodate 2,500 spectators. The doubly curved, wave-inspired roof of 1,040m2 is clad in a dual-alloy, mill-fnish, Kalzip aluminium standing-seam roof, with a gauge of 1mm, an upstand of 65mm and a module of 333mm for 90% of the roof sheets.

7.16 The 2012 Olympic Aquatics Centre, London, by Zaha Hadid Architects, 2011, photographed in 2014.

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Kalzip XT was specifed to accommodate the rapid changes in curvature of this roof.17 Kalzip XT uses patented roll-forming technology to fabricate standing-seam roof panels, with concave or convex curvature as required by the geometry of a specifc project. It was introduced by Kalzip in 2005 and frst used on the roof of Spencer Street Station in Melbourne, Australia, by Grimshaw (2006). Based on its experience of Kalzip

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XT, Lakersmere installed the Aquatics Centre’s aluminium standing-seam roof. Zaha Hadid Architects’ original geometry of the roof required the use of 40% Kalzip XT; in collaboration with Lakersmere and Kalzip, this was reduced to only 10%, without compromising the geometry.18 The aluminium roofng contract contributed only £3.5 million to the capital cost of the Aquatics Centre.19 The thermally efcient Kalzip fxing clips are fxed to cladding rails, which are in turn fxed, via the vapour check layer, to a trapezoidal roof sheet – this zone was then flled with insulation.

7.17 The 2012 Olympic Aquatics Centre during the Paralympics.

The soft of the roof is clad in reddish Louro timber strips, which articulate the direction of the swimming lanes below. Just four concrete columns support the dramatic roof. The steel roof structure was fabricated in Wales by Rowecord Engineering and weighs 3,200 tonnes. Today, any citizen of London and visitors to the capital can swim in the elegance of the Aquatics Centre for a modest cost. More than eight million people have used the centre since it reopened in March 2014. 189

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7.18 Installing the aluminium standing-seam roof sheets of the 2012 Olympic Aquatics Centre onto the thermally efcient fxing clips.

7.19 In March 2014, the Aquatics Centre reopened for all swimmers.

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Manor Works, by Architecture 00, completed in 2014, has been carefully designed in the context and topography of its site, making the most of a backland site in southeast Shefeld. This new-build industrial incubator is robustly detailed with an internal palette of exposed concrete, timber and plywood. It ofers managed workspace for local start-up businesses, from industrial or workshop units to ofces, combined with shared resources for the local community. The workspace is arranged to encourage the workers of the start-up companies to meet and share experiences and opportunities: in essence, the opposite of the earlier lock-ups on the adjacent site. The interior would not look out of place on a university campus. It is robust yet has an almost domestic quality. This economic building is part of the knowledge economy, yet it cost less than £1,700/m2, providing 1,600m2 of occupiable space for a capital cost of £2.7 million. The section of Manor Works makes the most of the site, ofering a range of spaces, with the communal areas located along the south façade, relating to a pedestrian footpath and local playing felds beyond. At its lowest level, Manor Works opens out onto this footpath and onto a modest play area, commissioned as part of the project. The north and west façades comprise standard composite metal panels. The east and south façades are unifed by perforated aluminium rainscreen panels, which become the skin of the project and act as solar shading and securing screens. These generously perforated aluminium panels also act as supports for climbing plants.

7.20 The perforated aluminium cladding provides continuity and solar shading on the east and south façades of Manor Works. 7.21 Manor Works by Architecture 00, photographed in 2014.

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Powerful and Sympathetic

7.22 The Hive in Milan on the opening day, 1 May 2015.

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The overall theme of the Milan Expo, held in 2015, was ‘Feeding the Planet: Energy for life’.20 The masterplan of the expo was designed by Herzog & de Meuron. Wolfgang Buttress, an artist based in Nottingham, won the commission to design the UK Pavilion, the Hive, in a limited competition. Pavilions are public, highly visited and the closest the industry has to an experimental architecture. Buttress’s response to the theme of the expo was to focus on the humble honeybee, its role as key pollinator of crops and the current risk to the wellbeing

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of the apian population. He explained, ‘Bees are incredibly sensitive to subtle variations and changes in conditions and their environment… So the bee can be seen as a sentinel of the earth and a barometer for the health of the Earth.’21 Buttress also took inspiration from Richard Buckminster Fuller – ecologically, philosophically and for the tectonics of the Hive. The delivery of the complete experience at the UK Pavilion involved Buttress’s studio embracing a series of multidisciplinary collaborations. His ambition for the UK Pavilion was ‘to integrate art, architecture, landscape and science’.22 To design and deliver the Hive, Buttress led a multidisciplinary team of collaborators including executive architect BDP Manchester, who were also the landscape architect, and structural engineer Tristan Simmonds of Simmonds Studio. The pavilion site in Milan was 100m deep. It was laid out as a narrative journey through an idealised fragment of a British landscape, with an orchard and a wildfower meadow, culminating in the Hive. The pavilion was placed frmly within the English picturesque landscape tradition, but delivered utilising 21st-century technology. Buttress refected, ‘I feel a connection to the romantic notion of the sublime – both the wonder and terror of nature.’23

7.23 Wolfgang Buttress’s early sketch of the Hive.

The Hive is a fascinating combination of Euclidean geometry and accretive complexity that is probably only possible using three-dimensional computer modelling. It is a 14m cube with a 9m spherical void at its core and it is lifted 3m of the ground plane by 18 circular, hollow-section steel columns, which are 139.7mm by 5mm. These columns rise 5m to meet a 10.8m-diameter ring beam. The Hive was assembled in 32 horizontal layers of aluminium components, with six layers below the ring beam to complete the base of the spherical void. It was assembled by accretion, as bees assemble a hive. The layers are linked to form truss-like assemblies. Aluminium was chosen in preference to stainless steel for economy, weight and relative ease of machining the components. The structure was parametrically optimised via close collaboration between Buttress Studio and the structural engineer Tristan Simmonds, who explained that the ‘basis of the Hive geometry is a radial hexagonal grid that is rotated slightly at each layer to give a twist. It is generated by repetition.’24 He recalled the design evolution as ‘a quick Darwinian process’.25 Specialist fabricator Stage One was appointed as main contractor by UKTI (UK Trade and Investment) before the design completion and advised on the selection of the design team. Stage One fabricated the components of the Hive in York, using approximately 50 tonnes of aluminium. The total number of components that form the Hive is 169,300 and almost all of them were fabricated from aluminium.26 The components of the Hive were fabricated from 6082 TS aluminium alloy and all remained mill fnish. For Buttress, rawness was a key principle and he specifed materials ‘throughout the pavilion [that] are generally unprocessed and patinate naturally’.27 The components are primarily cut from 10mm-thick aluminium sheet; however, 15mm and 8mm gauged aluminium were also used. Aluminium tubes or rods join the fat plate top and bottom cords of each

7.24 The author interviewing Wolfgang Buttress inside the spherical void at the heart of the Hive, at the Royal Botanic Gardens, Kew, in 2016, where the Hive was reassembled after the Milan Expo.

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truss-like layer. Stage One used laser cutting, waterjet cutting, and machining to fabricate the components. The spacer plates in the node connections were laser cut. All the radial and circumferential truss plates were waterjet cut and the rods and node tops were machined.28 Mark Johnson, CEO of Stage One, recalled: Over 4,500 CAD hours went into developing workshop drawings before machining, fnishing and packaging each component in specifc batches. Each item was etched with its own reference number relating to specifc positions within the Hive’s complex warren of hexagonal cells, ensuring our crew could complete the on-site construction in good time.29 The manufacturing took Stage One fve months, working 16 hours a day. The total time on site in Milan, from starting the groundworks in November 2014, was only six months. Stage One deployed 12 people on site, working piece by piece. The frst layer was completed in January and the structure of the pavilion was completely installed by April, in readiness for the opening of the Expo on May Day 2015.

7.25 Waterjet-cut 6082 TS aluminium alloy components of the structure of the Hive.

7.26 A trial assembly of several layers of the meshwork structure.

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7.27 The layers of the aluminium meshwork of the Hive are illuminated by programmable LED lights.

7.28 The 32 layers of the Hive on plan, from layer 1 (top left) to layer 32.

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7.29A and B Elevation (a) and section (b) of the Hive.

In the void at the core of the Hive, visitors experience sound and light that is a direct response to beehives in Nottingham. The bespoke LED light sources respond to accelerometers within the beehives. Stage One ‘designed, prototyped, refned and manufactured one thousand four-colour (RGBW) “pixels” [LEDs] bright enough to be seen in daylight’.30 The 891 light sources are arrayed around the void on each of the 32 levels. Stage One’s use of real-time, three-dimensional, computer-based ‘visualisations of the many lighting efects saved a great deal of time once on site’.31 7.30 Honeybees in a hive in Nottingham: visitors to the Hive experienced sound and light that was a direct response to beehives in Nottingham.

7.31 The aluminium meshwork structure of the Hive being assembled by Stage One in Milan.

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The experience in this void was ‘a dynamic soundscape, ever changing and unique at each moment: a collaboration between human and honeybee’. A live feed from Nottingham beehives was streamed to the pavilion in Milan, which triggered ‘noise gates at particular thresholds, opening sympathetic harmonious stems pre-recorded by musicians’. This was ‘mixed with sounds captured from the bee colony’.32

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7.32 Looking up to the glass foor of the Hive, which is at terrace level.

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7.33 Wolfgang Buttress at the Hive in the Royal Botanic Gardens, Kew.

The aluminium of the Hive was not recycled after the closure of the Milan Expo – a better option was found. The pavilion was disassembled and reassembled at the Royal Botanic Gardens, Kew, London. It reopened to the public on 18 June 2016. The detailing of the Hive, with all bolted connections, has facilitated is relocation; it is another example of the benefts of design for disassembly (DfD).33 The Royal Botanic Gardens, Kew, founded in 1840, holds the world’s largest collection of living plants and is a very appropriate second location for a pavilion inspired by pollinators. The Hive has been credited with raising attendance at Kew by 45%. In June 2018, Richmond Council granted it permanent planning permission. Its cultural value makes it more valuable than the sum of its environmental impacts. The Smithsonian National Museum of African American History and Culture (NMAAHC), in Washington, DC, by David Adjaye, Philip Freelon, Max Bond, Jr and SmithGroupJJR, was built on the last remaining site on the National Mall and completed in 2016.34 Josephine Minutillo observed in the Architectural Record at the time of its opening, ‘It has been over a hundred years since such a monument was frst proposed by black Civil War [1861–65] veterans and 13 years since President George W Bush signed legislation to build it, following decades of lobbying.’35 The commission to design the NMAAHC was won in an international competition in 2009 by a team led by David Adjaye. Adjaye described the NMAAHC as a monument, memorial and museum, although the brief only called for a museum. He refected on the 400-year history of African American culture the NMAAHC traces: ‘The tragedy of 12 million people being displaced, a lot of them dying crossing the ocean… There is a kind of deep tragedy in it. 198

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7.34 The National Museum of African American History and Culture, Washington, DC, by David Adjaye, Philip Freelon, Max Bond, Jr and SmithGroupJJR, completed in 2016.

The project is loaded with things unsaid as well as things said. The building had to be explicit in its narrative.’36 The popularity of the museum is reminiscent of the success of the Centre Pompidou by Richard Rogers and Renzo Piano, in Paris, in 1977. The NMAAHC is a contemporary work of architecture in a Neoclassical setting, which responds to both its context and the narrative history celebrated in the building. The base is formed from a four-storey podium below the National Mall, including a concourse, theatre, cafe and the History Galleries, ‘the crypt of the building’, which are larger in plan than the visible Corona, suppressing the apparent scale of this major museum.37 The two primary elements of this composition are separated by a glazed ground foor, suggesting the beacon of the Corona foats above the landscape of the National Mall. The NMAAHC has a square plan and its façades face the cardinal points of the compass. These four façades are essentially identical, reminiscent of the Villa Rotunda, near Vicenza, by Andrea Palladio (1570),38 which is a clear antecedent to the White House in Washington, DC. Adjaye breaks this symmetry on the south façade by the deployment of a 55m spanning canopy to form an entrance porch. The cast aluminium cladding is treated as a universal system on all four façades. However, its primary performative role is to act as solar shading, helping the building to achieve LEED Gold.39 This role is not required on the north façade, thus the formal or narrative intent of the cladding has determined the design thinking of the architect. 199

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7.35 The National Museum of African American History and Culture is, in essence, a classical building.

The Corona comprises three tiers of cast aluminium panels, coated with bronze-coloured PVDF. The form was inspired by a Yoruban caryatid topped by a Corona. An original Yoruba column is displayed on the top foor of the NMAAHC and is on loan from the Haus der Kunst in Munich. The NMAAHC houses more than 37,000 artefacts, including jazz scores by John Coltrane and Chuck Berry’s 1973 Cadillac Eldorado. The inclined angle of the cast aluminium panels is a direct inversion of the 17º pyramidal cap of the Washington Monument. Architect Robert Mills won the competition for this monument to President George Washington in 1845, but it was not completed externally until 1884, when the almost 170m-high stone obelisk was topped of by a cast aluminium cap that forms part of the lightning protection of the monument. This is one of the earliest uses of aluminium in civic architecture. The cast aluminium panels of the NMAAHC draw on the metalworking traditions of freed African American slaves, in cities such as New Orleans. There is also a broader tradition of the use of castings in North America, from the cast-iron façades in Chicago by Louis Sullivan – such as the Carson, Pirie, Scott and Company Store, 1899 – to the cast aluminium spandrel panels used by the architect William Lamb to clad the Empire State Building in New York, 1931.

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7.36 The generous canopy over the main entrance to the NMAAHC.

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7.37 The tracery of a cast-iron balcony in New Orleans, photographed between 1926 and 1929.

Cast aluminium was considered in competition with ultra-high strength concrete (UHSC) and bronze.40 Adjaye selected cast aluminium for its light weight and durability, the latter responding to the Smithsonian’s brief for a 50-year guarantee. Six patterns are used in the cast aluminium panels that range in opacity from 65 to 90%. Aluminium alloy used to cast the panels is equivalent to 3003-H14. The panels were cast using tooling made by Peerless Pattern Works, Inc., and cast in a foundry in Seattle by Morel Industries. The typical panel size is 1,600mm high by 1,048mm wide and 38mm deep. Sample panels now form part of the NMAAHC’s collection.41 Casting the panels from aluminium instead of bronze makes them much lighter and thus they can be readily assembled and dissembled. Adjaye explained, ‘They are in the safety limits of allowing four strong men to be able to fx one – like glass, like the weight of a big, heavy double-glazed panel of glass. Whereas, bronze would be 10, 20 times as heavy.’42 It was the foundry that made the design team aware of the sustainability of using recycled aluminium. At the NMAAHC, the cast aluminium panels are coated in a bronze-coloured PVDF wet paint system by Dura Industries. Apparently, PVDF was chosen in preference to bronze anodising for colour consistency between batches of panels. For Adjaye, materials, when used as components within architecture, ‘do not simply operate on their own account; the context in which you place them informs how they read.’43 The design and depth of the cast panels help to generate a diversity of refection and refractions from the façade. 202

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7.38 Six patterns of cast aluminium panels are used on all four elevations of the NMAAHC.

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7.39 The inclined angle of the cast aluminium panels of the NMAAHC is a direct inversion of the 17º pyramidal cast aluminium cap of the Washington Monument.

7.40 The author in the ofce of the Aluminum Association, in Arlington, Virginia, holding a full-sized replica of the cast aluminium cap of the Washington Monument.

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On the steps of the Lincoln Memorial on the National Mall, on 28 August 1963, Martin Luther King, Jr delivered his famous ‘I have a dream speech’ – a dream of equality. Lonnie G Bunch III, Director of the NMAAHC, described his hope: ‘This building will sing for all of us.’44

7.41 The NMAAHC is a building that sings for all of us.

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8.1 Niagara Falls: 96% of the energy used in Québec to smelt aluminium is from renewable sources, including hydroelectricity.

CHAPTER 8

Sustainability We can create transformational action that will safeguard the living conditions for future generations. 1 GRETA THUNBERG

The need to tackle climate change is evident. On 12 December 2015, the COP21 meeting in Paris announced a global agreement on climate change: the United Nations had spent 23 years seeking a collective agreement to tackle this issue.2 COP26, in Glasgow in 2021, produced a Climate Pack that kept the target of a global increase in temperature to 1.5°C above pre-industrial levels, but with no great certainty that this will be achieved unless the progression to net zero carbon is met by all sectors and all nations.3 Collectively, humankind has the science, software and skills to achieve the goal of keeping a global climate temperature increase to only 1.5°C. With the built environment and transportation representing 79% of CO2e (carbon dioxide equivalent) emissions in Britain,4 design teams have an immense role to play in the success of low-carbon architecture and infrastructure.

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8.2 The world power mix used to produce aluminium, reported between 1980 and 2020 (GWh). Note the use of renewables beyond hydroelectricity since 2016 (IAI data, 2020).

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8.3 Life Cycle Assessment results for each of the energy sources used to smelt aluminium. Negative values are possible because recycling credit assumes the avoided primary material would have been produced using the global average energy mix.5

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8.4 Sophos Operational Headquarters, Abingdon, Oxfordshire, by Bennetts Associates, building envelope consultant Michael Stacey Architects, 2003.

If you are evaluating aluminium for a current project, the frst four considerations are its durability, the power mix used to produce the aluminium, its recyclability and its in-use benefts. Durability of aluminium is set out in Chapter 4. Regarding the power mix used to smelt the aluminium, when produced by hydroelectricity it has a negative global warming potential, but there is some fossil fuel depletion. Taking Canada as an example, the production of aluminium is based on 96% renewable energy, primarily hydroelectricity as smelting aluminium is a continuous process. In 2003, at Sophos Operational Headquarters, Abingdon, Oxfordshire, architect Bennetts Associates and the author successfully specifed roof lights fabricated solely from aluminium produced by hydroelectricity within the context of a commercial building contract. This was sourced from Canada, thus successfully lowering the embodied impacts of this project. To maintain this saving in embodied impacts, it was of vital importance to source the double- or triple-glazing units locally. Therefore, specifying the power mix used to produce aluminium and its alloys should be part of project specifcations, with certifcates of conformity to evidence this, potentially in the form of an Environmental Product Declaration (EPD).

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8.5 Centre for Window and Curtain Walling Technology (CWCT) site weather test of the roof lights of Sophos Operational Headquarters, Abingdon, Oxfordshire, 2003.

The only smelter remaining in the UK is the Lochaber hydroelectrical aluminium smelter at Fort William, Scotland. Thus, the embodied impacts of aluminium produced by hydroelectricity should be the base case in UK data bases. The Lochaber smelter is owned by Alvance Aluminium Group, which is expanding this facility, including an increased smelting and recycling capacity, serving all sectors, including construction. The aim of Alvance is to become carbon neutral in its production of aluminium by 2030.

Recyclability The recyclability of aluminium is a fundamental quality of this light metal and it has been consistently recycled since global fows were frst recorded in the 1950s. More than one billion tonnes of aluminium have been produced since 1886, the year the Hall-Heroult process was invented. Three-quarters of this metal is still in productive use, a resource that can be considered a material and energy bank for humankind today and in the future. Around 35% is found in buildings, 30% in electrical cables and machinery and 30% in transport applications. Packaging products, because of their relatively short lifetimes, make up less than one percent of aluminium in use, even though this use makes up to 12% of annual metal demand.6 The aluminium drinks can is the world’s most recycled packaging container and can be back in use and on the shelf as another can in as little as six weeks after previous use. Or this aluminium alloy could be used to produce your next aluminium standing-seam roofng sheets.7 209

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8.6 Post-consumer aluminium scrap, primarily drinks cans, from the UK being loaded into the furnace of Hydro’s cast house, Holmestrand, Norway, witnessed by the author. Some 95% of UK drinks cans are recycled within the UK and Europe.

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Aluminium is almost infnitely recyclable, with no loss of material qualities.8 Based on a collection rate of 95% and a process loss during the recycling process of between 1 and 2% of aluminium by mass (lost primarily due to oxidisation), combined with a mean service life of 80 years, aluminium building components are recyclable for 4,000 years. Recycling aluminium requires only 5% of the energy used to produce aluminium from bauxite.9 Each tonne of aluminium recycled saves approximately 15 tonnes of CO2e. Globally, the recycling of 20 tonnes of post-consumer scrap aluminium eliminates almost 300 million tonnes of CO2e per year.10 If an aluminium building component is being recycled, the presence of anodising does not inhibit the process, nor does PPC (polyester powder coating). Within Europe, the energy required to produce primary aluminium ingots is on average 140MJ/ kg; however, this fgure is dependent on the efciency of the energy mix used for smelting. In comparison, the primary energy required to produce recycled aluminium ingots is 5.9MJ/kg. This fgure is for wrought aluminium, produced via recycled window frames, for example.11 The embodied carbon of primary aluminium produced using hydroelectricity is 10,880kgCO2e/m3 and the embodied carbon of 75% post-consumer recycled aluminium is 6,256kgCO2e/m3.12

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Global flow of aluminium

Not only is there a need to conceive of the built environment as a system set in the context of time, biodiversity and ecology, there is also a need to view materials objectively rather than from an ideological standpoint. All buildings are an alliance of materials, each with a performative role within the constructive details of architecture and infrastructure. Life Cycle Assessment (LCA) is an internationally recognised means of modelling the embodied impacts of a material, product or whole building assembly, and provides a more rounded view of the impacts of materials than headline embodied energy fgures. Globally in 2019, around 33 million tonnes, or 34% of global aluminium demand, was met from recycled aluminium.13 Therefore, in your next project specifcation consider not requesting more than 34% recycled aluminium content, unless you can organise a local closed-loop source. In the UK, post-consumer recycled aluminium is over 18 times more available than UK primary aluminium.14 The International Aluminium Institute predicts, as part of a pathway to only a 1.5°C increase in global temperature by 2050, that the production of primary aluminium will peak at 68 million tonnes, in part due to longer-life products. However, due to the availability of post-consumer recycled aluminium and better collection processes, the availability of recycled aluminium should triple by 2050. It is the recyclability of aluminium that is key and in an LCA, the end-of-service recycling method should be used; this applies to all metals.15

8.7 Global fow of aluminium (based on Allwood et al., 2001; additional mass fow data from IAI, 2015).

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Closing the Loop of Material Flow

8.8 The growth of primary production of aluminium and recycled aluminium from 1950 to 2019 (based on IAI data).

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The ‘OECD/IEA Joint Workshop on Sustainable Buildings: Towards sustainable use of building stock’ (2004) stressed that ‘the shift of mind-set, from traditional ways of perceiving the building process as linear (e.g., building from virgin materials and ending with demolition) to circular thinking (e.g., closing the loop of material flow), is necessary to improve the sustainability of the building sector’.16 Based on the findings of Towards Sustainable Cities (TSC) research, aluminium scrap has been consistently recovered from buildings upon demolition or disassembly since the early 1950s.17 The inherent recyclability of aluminium facilitates a closed-loop material flow.

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Closed-loop Recycling In Germany during 1994, five aluminium system suppliers (Hartmann, Hueck, Gartner, Schüco and Wicona) founded an association with a closed-loop recycling scheme for aluminium curtain walling, doors and windows. Walter Lonsinger led this organisation to make evident the recycling of aluminium to the local and federal government, in response to pressure groups who considered primary aluminium a high-embodied-impact material, unless recycled. Renamed A|U|F in 2010, this not-for-profit aluminium recycling scheme is an exemplar of closed-loop recycling on a local basis, with more than 200 members, including 11 recycling centres, across Germany.18 A|U|F’s aim is for other countries to set up national schemes to minimise the components miles and retain the resources in each region. In 2019, the Council for Aluminium in Building (CAB) set up a closed-loop recycling scheme for the UK. A pilot project included the recycling of fire-damaged curtain walling from a hotel in Bournemouth, which was only 11 years old, as part of the façade replacement contract undertaken by a Senior Architectural Systems fabricator. 212

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The TSC research found a wide-ranging use of recycled aluminium in architecture. Aluminium standing-seam roofs can be produced by Norsk Hydro using post-consumer aluminium drinks cans. There is also widespread use of cast aluminium made from recycled aluminium. The Ljubljana Television Centre, in Ljubljana, Slovenia, is clad in cast aluminium panels. Completed in 1974, it was designed by architect France Rihtar in collaboration with Branko Krasevac, who designed the façades. The aluminium panels were cast horizontally so that the surface was marked with the form of the cooling material. This gives a visual efect that is comparable to stone. 8.9 The Ljubljana Television Centre, in Ljubljana, Slovenia, used horizontally cast aluminium cladding panels in 1974.

8.10 The 92%-recycled cast aluminium solar shading of Heelis National Trust Headquarters, Swindon, by Feilden Clegg Bradley Studios, 2005, produced by Novacast in Melksham, only 28 miles away.

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Service Life of Buildings Typically, architecture and infrastructure, with lengthy life expectancy, represent long-term investments of resources and materials. In the briefng stages of a building design, a building’s life expectancy is normally related to the typology. Guidance was provided by BS 7543: 2003 Durability of Buildings and Building Elements, Products and Components, as shown in Table 8.1.

Table 8.1 Durability of buildings and building elements, products and components, based on BS 7543: 2003.

Category

Design service life for building

Examples

Temporary

Up to 10 years

Site huts; temporary exhibition buildings

Short life

Min. 10 years

Temporary classrooms; warehouses

Medium life

Min. 30 years

Industrial buildings; housing refurbishment

Normal life

Min. 60 years

Health, housing and educational buildings

Long life

Min. 120 years

Civic and high-quality buildings

The current edition of BS 7543: 2015 states, ‘The client should defne the design life of the building in the initial brief.’19 This is a backward step by British Standards, when we should be designing buildings and components to have a longer service life to contribute to resourcefulness and sustainability. This standard does provide guidance on the durability of building elements, products and components. In the USA, the median lifetime for commercial buildings is between 70 and 75 years, as calculated by the Pacifc Northwest National Laboratory for the US Department of Energy (2010).20 The median age of all buildings in the USA is 56.5 years.21 The normal life in BS 7543 should be increased to a minimum of 80 years, with the same minimum service life for housing retrofts, as part of our journey to net zero.

8.11 Demolition of Heathrow Terminal 2, September 2010.

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Actual life expectancy does not necessarily relate to typology. A much-loved cottage, for example, may far exceed its original intended life expectancy by careful maintenance, or a project may be swept prematurely away by a change in land use or spatial redundancy. The World Economic Forum for COP27 (2022) estimates that 80% of the current global building stock will still be standing in 2050.22 Architecture and infrastructure typically have a long in-use phase, and the global building stock continues to grow. In essence, the reservoir or energy bank of aluminium in use in architecture and infrastructure will continue to grow as the 21st century progresses. This growth in building stock refects the fact that, since 2008, over half of the world’s population lives in cities.23 According to the United Nations, world population reached 8 billion in late 2022 and is projected to be 9.6 billion by 2050.24 The 2004 TU Delft study ‘Collection of Aluminium from Buildings in Europe’, commissioned by the European Aluminium Association, remains the only systematic study on the collection of aluminium from demolished buildings.25 It demonstrates collection rates for aluminium at demolition of between 92 and 98%.

Table 8.2 Collection of aluminium from buildings in Europe (table created by the author using data from the TU Delft study, 2004).26

Aluminium content grams per tonne of demolition waste

Collection rate (%)

49

95

Sinks, roof strips and chimneys

1923 (aluminium from 1963 renovations)

6,100

96

By mass, 87% of aluminium scrap collected came from the roof sheets, with 13% from windows, doors and smaller components

Department store, Frankfurt, Germany

1945

1,750

98

Interior aluminium retail ft-out, lighting, air-conditioning tubes, cable casings, windows, doors and exterior panelling

4

Courthouse, Wuppertal, Germany

Early 1960s

7,500

98

Windows and exterior cladding

5

Apartment building, Le Mans, France

1971

18

31

Small aluminium parts, e.g., door handles

6

272 apartments, Ridderkerk, Netherlands

1970s

31

95

Door and window grips, door thresholds, draught prevention strips and strips around windows

7

Elf Aquitaine Ofce, Pau, France

_

640

92

By mass, 67% of aluminium scrap was cladding and 13% solar shading

8

Pirelli factory and ofces, Milan, Italy

_

430

94

By mass, 40% was aluminium windows and 17% internal ceilings; remaining aluminium scrap from duct pipes, partition walls and door frames

9

BNP Paribas bank, Madrid, Spain

_

4,000

No.

Building

Date of construction

1

213 terraced houses, Eindhoven, Netherlands

1920s

2

Wembley Stadium, London, UK

3

95

Aluminium applications

Cladding, windows and ducts

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8.12 Demolition of the awardwinning 1999 Greenwich Sainsbury’s (architect Chetwoods) in spring 2016, to make way for a new IKEA. The demolition contractor retrieved over 95% of the 5,000m2 aluminium standingseam roof, and other aluminium components, including the curtain walling.

A relative criticism of this study is that the age of the buildings when demolished was in some cases either not recorded or not known. Within Table 8.2, the author has added the date of construction when this data is separately available; for example, the aluminium roof of the frst Wembley Stadium was installed in 1963, while the stadium opened in 1923. It is interesting to observe that the demolition of 1920s terraced housing in the Netherlands yielded signifcant aluminium scrap, although not all of it was part of the original construction; this included aluminium components such as kitchen sinks and carpet trims.27 Improvements in recycling sorting technology since the TU Delft study, including x-ray separation and laser scanning, have enabled the capture of even small aluminium parts. Within a BREEAM Resource Management Plan, the materials identifed in the Demolition Audit of the existing building should be recycled at a minimum of 95% to achieve the related credit in the BREEAM assessment of the new building. In the UK, reputable waste management centres work to just above this target level. Therefore, a 95% recycling rate is the norm for buildings that are demolished to make way for a BREEAM-assessed new building.

8.13 (opposite) 1951 Festival of Britain, London – Skylon by Powell and Moya, and the Dome of Discovery, by Ralf Tubbs and consulting engineers Freeman Fox and Partners.

216

The Dome of Discovery was built as an exhibition space for the Festival of Britain celebrations held on London’s South Bank in 1951. Designed by Ralph Tubbs with consulting engineers Freeman Fox and Partners, the dome quickly became an iconic structure, helping to popularise modern design in Britain. Aluminium was used for structural members and for the cladding of the dome; this was due to steel being in short supply following the Second World War, and also ‘for its lightness [and] because it captured the spirit of the post war years’.28

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8.14 The riveting of the aluminium roof cladding of the Dome of Discovery: workers, architect and engineer – at its best, the construction industry is based on close collaboration.

The dome exemplifed the British enthusiasm for inventiveness and experimentation by having a diameter of 111m and a height of 28m, making it at the time the largest in the world, and by using the latest technology and materials. The external aluminium trussed masts provided resistance to the dome’s outward forces, while creating sheltered external space, and an everchanging vista for the visitor walking around the perimeter. Controversially, following the popular Festival of Britain, the new Conservative government (elected in October 1951) demolished the dome and sold it as scrap to George Cohen, Sons and Company of London. In an attempt to save the dome, Tubbs and Freeman Fox costed the relocation of the dome to the former site of Crystal Palace, which amounted to £55,000 – but this never materialised.29 The Skylon, designed by Powell and Moya, a key symbol of the Festival of Britain, was also clad in aluminium. On its disassembly, this too was sold to George Cohen, Sons and Company and was combined with the aluminium recycled from the Dome of Discovery. This raised £24,000 and would have amounted to a large proportion of the recycled aluminium available in Britain in 1952.30 The global fow of aluminium has been recorded since 1952 and for over 70 years recycled aluminium has formed a key part of this.

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8.15 The modular diagrid aluminium structure of the Discovery Dome of Discovery, 1951 Festival of Britain.

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Resourcefulness, Reinvention and Reuse A vital component in achieving sustainable development is the resourceful use of materials in delivering products, artefacts and services. The three cornerstones of resourceful material usage are reduce, reuse and recycle. Advances in materials science, digital design and fnite element analysis mean that humankind can do more with less, achieving the same or a better level of performance while using less aluminium to form a window section, a curtain-walling mullion or an aluminium structure.31 The frst mode of reuse in architecture is to fnd a new use for an existing building, with many humble and high-profle examples throughout the world. The successful reuse of existing buildings ofers signifcant social, environmental and economic benefts for a wide range of architecture typologies, particularly if the energy performance of the existing building stock is improved through, for example, enhanced thermal performance with increased levels of insulation, high-performance double- or triple glazing and improved airtightness of the building envelope.32 The successful delivery of architecture with low operational energy requirements increases the importance of the energy of construction embodied in its materials and systems. The social, economic and cultural value of existing buildings, including the resource of embodied energy, has led to the practice of deep retroft or reinvention of architecture. In this process, rather than full demolition the original building is stripped back to its basic structure and then reclad, not necessarily following the original footprint, as is evident in the design of the Churchill Centre, in Rotterdam, by Brookes Stacey Randal Fursdon (1996). Such projects technically and aesthetically update the architecture, while retaining the performative role and embodied energy of the steel, masonry or concrete elements. The potential benefts of an increased reuse of existing buildings are clearly articulated in ‘The Greenest Building: Quantifying the Value of Building Reuse’.33 This report shows that retroft is not always the lowest-carbon option – the conversion of a warehouse to residential apartments had a great environmental impact compared to new build. The range of options for each project should be evaluated by the design and client team. 34 Cultural heritage within architecture and infrastructure is now highly valued and has become a global movement, as evidenced by the number of UNESCO World Heritage Sites.35 Priority is often placed by society on the cultural or heritage value of architecture and infrastructure beyond its original use, be this a former factory or a castle, both of which may have become functionally redundant due to technological change. The rise of interest in construction heritage dates back to the mid-19th century. However, this became much more signifcant after 1972, when the UN Convention Concerning the Protection of the World Cultural and Natural Heritage was agreed. This has emphasised the value of retention and the need for the reinvention of architecture and building fabric rather than demolition.

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8.16 A and B The Churchill Centre, Rotterdam, by Brookes Stacey Randall Fursdon, 1996, before (a) and after (b). The concrete frame of the twin shopping centre was retained and was reclad with a lightweight, wellinsulated skin, increasing the lettable area by 40%.

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The second form of reuse within architecture is relocation, for example the Aluminium Centenary Pavilion by Jean Prouve (see Chapter 2), which has been located in central Paris on the south bank of the River Seine (1954), then in Lille (1956) and since 2000 it is now located back in Paris at Villepinte. Another example is the Hive (see Chapter 7), which was in Milan (2015) and now London (since 2016). Design for Manufacture, Assembly, Disassembly and End of Service Life (MADE, BS 8887-1:2006) facilitates relocation and the reuse of individual components on a new project. The fnal mode for architecture and infrastructure when no longer useful is demolition or disassembly combined with recycling of the building’s components and materials. It is reasonable to predict that the use of building information modelling (BIM) for design and facilities management will facilitate the reuse, relocation and recycling of aluminium architectural components, as data on the materials are embedded in the model.

In-use Benefts A component of the TSC research programme used LCA to evaluate the embodied impacts of materials used to form window frames: aluminium, wood, aluminium-clad wood and PVCu with an 80-year in-use phase.36 Many LCAs do not consider the in-use phase, which is very important in buildings and infrastructure as they typically have a long service life. This study considered the efect of maintenance on the embodied impacts of the four window frame materials, in three scenarios – no maintenance, basic maintenance and high maintenance – over an 80-year service life.37 The all-aluminium window has the lowest embodied impacts and the lowest impacts when well maintained, despite the embodied impacts of regular cleaning. The results are summarised in a peer-reviewed paper by Efrie Friedlander and Stephanie Carlisle, ‘The Infuence of Durability and Recycling on Life Cycle Impacts of Window Frame Assemblies’.38 Maintenance or stewardship is a fundamental part of sustainability. However, many major building clients, for example universities, have in the recent past built up very signifcant maintenance backlogs.

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A C I D I FI C A TI O N

G L OB A L W A R M I N G P OT E N T I A L 1400

8

1200 6

kg SO2 eq

kg CO2 eq

1000 800 600 400

4

2

200

0

S1

S2

S3

S1

S2

S3

W OOD

A L UMI NI UM

S1

S2

A L UMI NI UM C L AD

S1

S2

0

S1

S2

S3

S1

S3

W OOD

ALUMINIUM

P VCU

S2

S1

S2

ALU MINIUM CLA D

S1

S2

P VC U

E UTR O PH I C A TI O N

O ZON E D E P L E T I ON 1.00E-04 3.5 3 2.5

6.00E-05

kg N eq

kg CFC-11 eq

8.00E-05

4.00E-05

1

2.00E-05 0.00E+00

2 1.5

S1

S2

S3

S1

S2

S3

W OOD

A L UMI NI UM

S1

S2

A L UMI NI UM C L AD

S1

0.5

S2

0

P VCU

S2

S3

S1

S2

S3

W OOD

S1

S2

A LUMINIUM CLA D

S1

S2

P VC U

FO S S I L FUE L D E PL E TI O N

S M OG F OR M A T I ON 70

1600

MJ Surplus

60 50 40

1200

800

30 20 10 0

S1

S2

S3

A L U M I NI UM

Clad Wood

kg 03 eq

S1

A LUMINIUM

400

S1

S2

S3

W OOD

S1

S2

A L U MI NI UM C L AD

S1

S2

P VCU

0

S1

S2

S3

A LUMINIUM

S1

S2

S3

W OOD

S1

S2

A LUMINIUM CLA D

S1

S2

P VC U

8.17 LCA results for each of the window assemblies and in-use scenarios across TRACI 2.1 impact categories.39 Scenario Three was not a viable option for aluminium-clad wood or PVCu, and is therefore not represented. Scenario 1: Guaranteed service life Scenario 2: Basic maintenance Scenario 3: High maintenance

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Fire A key component of durability and sustainability is designing for fre safety. The tragic fre in the 24-storey Grenfell Tower block of fats in west London that killed 72 people in 2017 is beyond the scope of this book; for more information see the fndings of the Public Inquiry40 and the article ‘Overcladding: An uncertain panacea’ (1988), written by the author with Alan Brookes for the Architects’ Journal, warning of the risk of such a fre in rainscreen cladding.41 It is essential that all the components of overcladding are non-combustible and that the frestops are carefully installed to prevent a chimney-like cavity being formed behind the rainscreen. The overcladding needs to be well designed, subject to large-scale holistic testing and carefully installed. Aluminium is non-combustible – it will melt at over 660°C and not burn. This applies to a 3mm-thick aluminium cladding panel. Under EN 13501-1, anodised aluminium is classed as A1, as is coil-coated PVDF (polyvinyl fuoride coatings). Polyester powder coating, which is typically at least 40microns thick, does add a very small fre load and is classifed under EN 13501-1 as A2-S1, D0 (where S1 equates to little or no smoke and D0 represents no faming droplets). Therefore, all three of these very durable coatings on aluminium can be used on buildings of over 18m in England and Wales and 11m in Scotland under Part B of the Building regulations. In three large-scale holistic tests, 3mm-thick aluminium-clad façade systems, all using non-combustible mineral wool insulation, have been successfully tested to BS 8414; AkzoNobel were one of the industrial partners in this testing programme.42

Overcladding Guy’s Hospital Tower overcladding, designed by Penoyre and Prasad Architects with Arup Facades, 2014, is an exemplar of how non-combustible insulation and aluminium rainscreens can dramatically reduce the carbon footprint of a major NHS hospital. Guy’s Hospital Tower was designed in the 1960s by Watkins Gray Architects; construction started in April 1968 and it opened in 1974. At a height of 143m, this was the tallest hospital in the world when built. Guy’s Hospital Tower actually comprises two towers: the User Tower, with its simple uninterrupted foor plates of 1,200m2, which have readily accommodated changes over time, and the 34-storey Communications Tower, which houses the stairs, lifts, ventilation and services risers. The Communications Tower is dramatically capped by a lecture theatre that cantilevers out above the 28th foor. Guy’s Hospital Tower was designed, with exposed concrete, in a direct Constructivist manner, an example of what some mistakenly describe as Brutalist architecture. The vertical nature of the Communications Tower was emphasised by ribbed concrete, whereas the User Tower has a horizontal expression. In 2008, inspections and a feasibility study identifed that the concrete of the Communications Tower was spalling badly. The concrete balconies of the User Tower were in a better condition, however they did require cleaning. The double-glazed steel windows were badly 224

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8.18 Guy’s Hospital Tower overcladding, designed by Penoyre and Prasad Architects with Arup Facades, 2014.

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corroded, with some fogged double-glazed units and, on testing, were found to ofer poor thermal performance. Between April 2012 and spring 2014, Guy’s Hospital Tower was overclad and reglazed with curtain walling, designed by Penoyre and Prasad, working with Arup Facades. The architects carefully considered how the two towers read from the street context and across the cityscape of London, articulating the reinvigoration of the hospital, yet retaining the Constructivist expression of the original design. Laura Macfarlane, of Arup Facades, refected that ‘this very successful project was in part a result of the close collaboration within the multidisciplinary design team and with the client, contractors and specialist fabricators of the aluminium façade systems’.43 The overcladding and curtain walling was fabricated and installed by Permasteelisa. The capital cost of this project was £40 million.

8.19 The original Guy’s Hospital Tower, designed by Watkins Gray Architects and completed in 1974. The design is more Constructivist than Brutalist.

8.20 The overcladding strategy for the User Tower, primarily composing pale umber anodised aluminium curtain walling and spandrel panels, insulation and reveals.

226

A carefully considered family of aluminium components includes the curtain walling and spandrel panels, fnished in a pale umber anodising that respond to the existing white concrete balconies and provides counterpoint to the medium blue-grey anodised overcladding. The overcladding protects 180mm of additional mineral wool insulation and achieves a U-value of 0.15W/m2K, combined with new double-glazed curtain walling providing a U-value of 1.44W/m2K. The curtain walling is approximately 50% glazed, with an argon-flled doubled-glazed unit, held in thermally broken extruded aluminium framing. The double-glazed units utilise a solar-selective glass to balance solar gain in spring, summer and autumn and maintain high levels of natural light. Permasteelisa employed a team of 70 workers to install the 8,000m2 of aluminium cladding panels and 12,000m2 of glazing units. Through careful phasing, the hospital remained operational throughout the contract.44 The curtain walling of the User Tower was installed outside the existing building fabric, enabling continuity of occupation and the removal of the steel windows from inside.

S U S TA I N A B I L I T Y

The origami-folded anodised aluminium panels designed by Penoyre and Prasad have a sculptural quality, ‘seen from a distance, it gives the Tower a solid hewn feel’,45 yet on bright and sunny days the angled facets light up, providing a play of light across the expansive faces of this tower. At Permasteelisa, a two-person team folded 3,500 aluminium panels by hand with a press brake. The panels were fabricated using 3mm-thick aluminium, as the folded panels were required to span vertically between two fxing rails almost 4m apart. There is an interesting correspondence to the pressed and anodised aluminium panels of the Alcoa Building in Pittsburgh (1953), designed by Harrison and Abramovitz (see Chapter 2).46

8.21 Overcladding for Guy’s Hospital Tower primarily comprises folded blue-grey anodised aluminium rainscreen panels with pale umber anodised aluminium curtain walling and spandrel panels.

8.22 The cantilevered lecture theatre of the Communications Tower is clad in blue-grey anodised aluminium fat rainscreen panels to emphasise its presence.

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8.23 Junctions between the folded aluminium cladding and the glazing are carefully considered.

The folded aluminium panels of Guy’s are fnished in blue-grey anodising (Anolok II B715) applied in accordance with BS 3987: 1991 at 25µm by United Anodisers in its Uxbridge plant. United Anodisers is a Qualanod-registered company and thus subject to periodic quality inspections. United Anodisers provides a lifetime guarantee on its anodising.47 The pale umber anodising (Anolok 541) primarily used on the curtain walling was also applied by United Anodisers at 25µm in its plant in Huddersfeld, to the same standard and quality regime. To inform the design development of the overcladding, an LCA was conducted using GaBi software.48 Although undertaken by Arup, Andrea Charlson noted, ‘Both the client, Guy’s and St Thomas’ NHS Foundation Trust, and the architect, Penoyre and Prasad, had a keen interest in the overall sustainability of the project and as part of this it was decided to look at the life cycle impacts of the façade.’49 The cleaning frequency used in this LCA was: glazing one month, spandrels three months and overcladding 12 months. The calculated carbon payback period for this overcladding and curtain walling is under 13 years. Based on an 80-year service life, the new building envelope will save over 22,100 tonnes of CO2e.50

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8.24 The carbon payback period for the overcladding of Guy’s Hospital Tower is under 13 years.

8.25 Juxtaposition of the User Tower balconies and a corner of the Communications Tower.

The overcladding of Guy’s Hospital Tower is an exemplar of the work the National Health Service needs to commission on its extensive and ageing estate in the UK, providing comfort while saving primary energy and carbon dioxide emissions. The carbon payback period more than justifies the capital expenditure, providing comfort for the staff and patients while saving CO2e. Furthermore, the anodised aluminium has a durability of over 80 years, thus the savings should continue through this century. 229

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Integration and Sustainability

8.26 The aluminium petals of the ceiling of Bloomberg are an exemplar of sustainable and integrated product design by an architect-led design team

230

In 2018, Bloomberg’s European headquarters in the City of London, designed by Foster & Partners won the RIBA Stirling Prize. Achieving a 98.5% BREEAM Outstanding rating, RIBA judges described it as ‘as the most sustainable ofce building in the world’.51 Michael Jones, project architect, considers the aluminium ceilings key to the sustainability of Bloomberg ‘inspired by the pressed metal ceilings of New York. Its distinctive polished aluminium panels of ‘petals’ perform multiple roles – ceiling fnish, light refectors, cooling elements and acoustic attenuation – combining various elements of a typical ofce ceiling into an energy-saving integrated system.’52 The ceiling comprises 2.5 million aluminium petals all manufactured by SAS ceilings in south Wales. These are highly integrated aluminium components delivering sustainability. The sculpted shape of the petals, designed using computational fuid dynamic modelling, maximises the surface area for heat exchange with slots that further improve energy transfer and provide acoustic absorbency to control the reverberation time in the open plan ofces. The form of the petals also minimises the light blocked from the LED light fttings.53

S U S TA I N A B I L I T Y

Technological Sophistication

Atmospheric steam engine, Thomas Newcomen, 1729

Iron Bridge, Coalbrookdale, 1779

Royal Navy Block Mills, Portsmouth Dockyard, the first mass-production line, 1802

Mass-production of traction engines, Richard Garrett & Sons, Suffolk, 1852

RCA 630-TS, the first mass-produced television set,1946

First programmable logic controller, Modicom 084, 1969

The first power loom, Edmund Cartwright, 1787

First Industrial Revolution

IMac G3, 1999

Second Industrial Revolution

8.27 The four stages of the Industrial Revolution.

2000

1900

1800

1700

In this, the fourth Industrial Revolution, humankind can build on over 200 years of invention to tackle climate change, including deploying non-combustible insulation within well-detailed building envelopes to reduce energy demand, combining this with renewable energy technology, wherever possible. Collectively, humankind has the means to create low-carbon, carbon-neutral and energy-positive architecture which tackles the risk of climate change.

Third Industrial Revolution

Time

International Space Station, 2000

Wind farms: renewable wind turbines

Net zero carbon homes

Four Green Industrial Revolution

231

Notes

INTRODUCTION

CHAPTER 1

1

1

2

3

4

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The ‘2014 Revision of World Urbanization Prospects’, prepared by the Population Division of the Department of Economic and Social Afairs of the United Nations, states that 54% of humanity now lives in urban areas, https://esa.un.org/unpd/wup (accessed June 2022). N Foster of Foster + Partners, speaking in ‘Dreaming the Impossible: Unbuilt Britain’, Episode 3, ‘A Revolution in the City’, BBC 4, 27 May 2017, transcribed by the author. Department for Business, Energy and Industrial Strategy, ‘UK Local Authority and Regional Greenhouse Gas Emissions National Statistics, 2005–2020’, 30 June 2022, www.gov.uk/government/statistics/ uk-local-authority-and-regional-greenhousegas-emissions-national-statistics-2005-to-2020 (accessed March 2023). CO2e (CO2 equivalent) is a metric used to measure the diverse greenhouse gases based on their global-warming potential, converting amounts of other gases to the equivalent amount of carbon dioxide with the same global-warming potential. L Magee, A Scerri, P James, JA Thom, L Padgham, S Hickmott, H Deng and F Cahill, ‘Reframing social sustainability reporting: Towards an engaged approach’, Environment Development Sustainability 15(1), 2013, pp 225–43. GH Brundtland, ‘Our Common Future: Report of the World Commission on Environment and Development’, United Nations, 1987, p 47, www.un-documents.net/ our-common-future.pdf (accessed April 2015). M Stacey, Aluminium: Sympathetic and Powerful: Towards Sustainable Cities, Riverside Architectural Press, 2020, pp 144–233.

2

3

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H Davy, ‘Electro chemical researches, on the decomposition of the earths; with observations on the metals obtained from the alkaline earths, and on the amalgam procured from ammonia’, Philosophical Transactions of the Royal Society, 1808, p 353. The mining of bauxite produces waste that is typically stored in tailing dams. In Brazil, Hydro now uses two dams and allows the waste to dry out in alternate dams, then areas that have already been mined are backflled. The land is then remediated and biodiversity potential is restored. See https://www.hydro.com/en-no/ about-hydro/stories-by-hydro/novel-bauxitetailings-concept-a-success-in-full-operation (accessed October 2022). (Hydro is a vertical aluminium company, from mining and recycling through to sheet and extruded aluminium alloy products and systems. It has 100 years’ experience of using renewable energy.) R Alfred, ‘April 2, 1889 aluminum process foils steep prices’, Wired Magazine, 4 May 2002, www.wired.com/2008/04/dayintech-0402 (accessed April 2019). Aluminum Association, ‘International Alloy Designations and Chemical Composition Limits for Wrought Aluminum and Wrought Aluminum Alloys’, 2018, https://www. aluminum.org/sites/default/fles/2021-11/ TealSheet.pdf (accessed March 2023). The global aluminium industry has harmonised the terminology used, with the exception that the North American aluminium industry uses the spelling aluminum. Global Advisory Group (GAG), ‘Guidance Document 001: Terms and Defnitions’, 3rd edition, 2011-01, https:// www.aluminum.org/sites/default/fles/2021-09/ GAG_001_Terms_and_Defnitions_3rd_ Edition_2011_01_August_21_2011_JW.pdf (accessed March 2023). BS EN 575:1996 can be accessed via https://knowledge.bsigroup.com/products/

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aluminium-and-aluminium-alloys-master-alloysproduced-by-melting-specifcations/standard (accessed March 2023). A useful summary of British and European standards for aluminium and its alloys can be found in Aluminium Federation, Properties of Aluminium and its Alloys, 2014. https://www.aluminum.org/sites/default/ fles/2021-09/AA-Infographic-Alloys-v5_0.jpg (accessed March 2023). Robert Victor Neher patented the continuous rolling process for aluminium in 1910; see www.alufoil.org/history.html (accessed February 2016). PL Jakab, ‘Wood to metal: The structural origins of the modern airplane’, Journal of Aircraft 36(6), AIAA, Nov–Dec 1999, pp 914–18. https://www.aluminum.org/sites/default/ fles/2021-09/AA-Infographic-Alloys-v5_0.jpg (accessed March 2023). www.sapagroup.com/en/newswall/2016/ sapa-developing-new-automotive-alloy-for-highstrength-applications (accessed April 2016). For the full composition of 7075 alloy see Aluminium Federation, Properties of Aluminium and its Alloys, p 38. Aluminum Association, ‘The Aluminum Association 2015 Annual Report’, Aluminum Association, 2015, p 17, http://www.aluminum. org/about-association/annual-reports (accessed February 2016). Aluminium Federation, Properties of Aluminium and its Alloys, pp 15–19. M Miodownik, ‘Metals: How It Works’, BBC 4, 2012, www.bbc.co.uk/programmes/p00qgy6x (accessed February 2016). J Dwight, Aluminium Design and Construction, Routledge, 1999, p 10. Ibid. Ibid. Y Baba, ‘Extra super duralumin and successive aluminum alloys for aircraft’, Journal of Japan Institute of Light Metals 39(5), 1989, p 379. Note duralumin is an alternative spelling of duraluminium.

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Canon D Buckley, The Parish of Fenny Bentley and its Church of St Edmund, King and Martyr, Ashbourne, 1987, cited in company focus: hoogovens, February 1998, np. Ibid. Ibid. EW Skerrey, Long-Term Atmospheric Performance of Aluminum and Aluminum Alloys, Wiley, 1982, pp 329–30. It was consecrated on 6 June 1911 by Cardinal Respighi in honour of Pope Leo XIII. F Samuel and I Linder-Gaillard, Sacred Concrete: The Churches of Le Corbusier, Birkhäuser, 2013, p 17. EW Skerrey, Long-Term Atmospheric Performance of Aluminum and Aluminum Alloys, pp 329–30. Ibid. St Mary the Virgin, Great Warley, Essex was listed Grade I by English Heritage on 20 February 1976. Historic England Listing number 1197210. AL Baldry, ‘A notable decorative achievement by W Reynolds-Stephens’, The Studio 34(143), February 1905, pp 3–15. W Alexander and A Street, Metals in the Service of Man, Penguin Books, 1944, 6th edition 1976, p 181. D Harris, ‘The world’s oldest aluminium casting’, http://www.dcsoc.org.uk/flemanager_net/fles/ The_Worlds_Oldest_Aluminium_Castings.pdf (accessed August 2013). N Pevsner, J Fleming and H Honour, Lexikon der Weltarchitektur [Encyclopaedia of World Architecture], Prestel, 1971, p 618, cited by J Tabor in Otto Wagner: Die Österreichische Postsparkasse [The Austrian Postal Savings Bank], Falter Verlag, 1996, p 31. Cited by J Tabor in Otto Wagner: Die Österreichische Postsparkasse, pp 36–37; also OA Graf, Otto Wagner: Das Werk des Architekten [The Work of the Architect], H Böhlaus Nachf, 1985, p 16. https://airandspace.si.edu/collectionobjects/1903-wright-fyer (accessed April 2019). S Giedion, Space, Time and Architecture: The Growth of a New Tradition, Harvard University Press, 1941, p 17. Otto Wagner, Modern Architecture, Getty Center for the History of Art and Humanities, distributed by the University of Chicago Press, 1896. Wagner: Werk Museum Postsparkasse is a museum dedicated to Otto Wagner’s competition-winning design and the

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construction of the Postsparkasse and is located behind the Main Banking Hall. J Tabor, Otto Wagner: Die Österreichische Postsparkasse, pp 36–37. Otto Wagner, Modern Architecture. In 1900, Albert Einstein stated, ‘A formula without beauty cannot be right’; both cited by J Tabor, Otto Wagner: Die Österreichische Postsparkasse, p 4. J Ashby, ‘The aluminium legacy: The history of the metal and its role in architecture’, Construction History 15, 1999, pp 79–90. ER Ford, Details of Modern Architecture, Volume 2: 1928 to 1988, The MIT Press, 2003, pp 248–55. BAC also designed and assembled aluminiumbased schools. It had completed 57 post-war schools by 31 July 1949. In 1951, Whitmore Park Primary School was hailed as the ‘largest aluminium school’ yet built, cited in B Russell, Building Systems, Industrialization and Architecture, Wiley, 1981, pp 226–28. B Vale, Prefabs: A History of the UK Temporary Housing Programme, E & FN Spon, 1995, p 16. Quoted in M Pawley, ‘A dose of morphine: The rise and fall of public sector housing’, Frieze 10, 1993, available online at www.frieze.com/ issue/article/a_dose_of_morphine (accessed December 2013). M Stacey, Aluminium Recyclability and Recycling: Towards Sustainable Cities, Cwningen Press, 2015, pp 170–81. AJ Brookes, ‘Development and use of gaskets in cladding systems’, Roofng, Cladding & Insulation, February 1985, pp 29–33. M Stacey, Component Design, Architectural Press, 2001, pp 43–44. Cited in P Serraino, Saarinen, Taschen, 2006, p 34. British Standard PD 6484: Commentary on Corrosion at Bimetallic Contacts and its Alleviation, BSI,1979. Anon, ‘Aluminum skyscraper’, Popular Mechanics, 100(6), December 1953, pp 86–87. Jean Prouve in 1949 designed unitised curtain walling for the Federation Nationale du Bâtiment Ofces, Paris, for architects Gravereaux & Lopez. Alcoa, Aluminum on the Skyline, 1954, p 3, cited in SC Nichols (ed), Aluminum by Design, Abarams, 2000, p 104. AJ Brookes, Cladding of Buildings, Construction Press, 1983, p 199. This inspection was carried out in June 2013 as part of a Towards Sustainable Cities (TSC) research project.

36 This inspection was carried out in December 2013 as part of a TSC research project. 37 Landmarks Preservation Commission, 20 June 1995, Designation List 265 LP-1920. CHAPTER 3

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W Alexander and A Street, Metals in the Service of Man, 6th edition, 1976, Penguin, p 276. D Sudjic, Future Systems, Phaidon, 2006, p 214. T Lane, ‘It’s a wrap’, 21 September 2021, www. building.co.uk/buildings/its-a-wrap-restoringselfridges-showstopper-status/5113761.article (accessed March 2022). M Stacey, Aluminium: Flexible and Light: Towards Sustainable Cities, Cwningen Press, 2016, pp 94–99. Ibid. M Stacey, Aluminium and Durability: Towards Sustainable Cities, 2nd edition, Cwningen Press, 2015, pp 100–101. www.3dmetalforming.com/organisation (accessed July 2015). PA Hilton, ‘The early days of laser cutting’, TWI, 2007, http://www.twi-global.com/ technical-knowledge/published-papers/the-earlydays-of-laser-cutting-august-2007 (accessed February 2016). BA Lengyel, Lasers: Generation of Light by Simulated Emission, John Wiley & Sons, 1962, pp 22–28. AGA, ‘Facts about cutting of aluminium’, (www. aga.com/international/web/lg/aga/like35agacom. nsf/repositorybyalias/facts_cut_alu_uk/$fle/ AGA+Cutting+Aluminium+Facts+About+UK.pdf (accessed February 2016). (AGA is a company in the Linde Group.) M Stacey, ‘From fat stock to three-dimensional immersion’, in P Beesley (ed), Kinetic Architectures and Geotextile Installations, Riverside Architectural Press, 2010, pp 59–64. M Stacey, Prototyping Architecture, Riverside Architectural Press, 2013. Making Architecture Research Studio (MARS) was the author’s Sixth Year RIBA Part 2 studio at the University of Nottingham. Wayne M Thomas et al., Friction Stir Welding, UK patent 9125978.8, 1991. PL Threadgill, AJ Leonard, HR Sherclif and PJ Withers, ‘Friction stir welding of aluminium alloys’, International Materials Reviews 54(2), March 2009, pp 49–93. WM Thomas, J Martin and CS Wiesner (2010), ‘Discovery, invention and innovation: Friction technologies – for the aluminium industries’, in L Katgerman and F Soetens (eds), 11th Inalco

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Conference 2010, New Frontiers in Light Metals, IOS Press, pp 13–22. Ibid. M Stacey, Digital Fabricators, University of Waterloo School of Architecture Press, 2004. Ibid. M Stacey, Prototyping Architecture, pp 200–3. Ibid, pp 210–13. Ibid. S Kieran and J Timberlake, Loblolly House: Elements of a New Architecture, Princeton Architectural Press, 2008. M Stacey, Aluminium and Durability. L Parks, ‘Aluminium in the home and ofce’, in A Barry (ed), Aluminium 1886–1986, MorganGrampian for ALFED, 1986, p 42. J Maier, Managing Director of WEFA, in conversation with the author, January 2016. Cost data supplied by Sapa UK in 2016. M Stacey, Aluminium Recyclability and Recycling: Towards Sustainable Cities, Cwningen Press, 2015. G Gibson, ‘Down to the last detail’, Crafts Magazine 254, May/June, 2015, p 94. J Ive, ‘Foreword’ to S Lovell, Dieter Rams: As Little Design as Possible, Phaidon, 2011, p 13.

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RJ Cordner, ‘Atmospheric corrosion survey of New Zealand’, British Corrosion Journal 25(2), 1990, pp 15–118. EW Skerrey, Long-Term Atmospheric Performance of Aluminum and Aluminum Alloys, Wiley 1982, p 330. G Sowinski and DO Sprowls, Weathering of Aluminum Alloys, Wiley, 1982, pp 297–328. G Sowinski and DO Sprowls, Weathering of Aluminum Alloys. K Barton, Protection Against Atmospheric Corrosion: Theories and Methods, Wiley, 1976. A Heyn, ‘Expert opinion: Evaluation of Kalzip profled sheet after long-term exposure at diferent locations’, VI.1/14669, German Federal Institute for Materials Research and Testing (BAM), 2009. Noting that pollution from vehicles, including particulates and nitrogen dioxide, can prove problematic to human health and therefore more work needs to be undertaken to control pollution, especially in our cities. Kalzip Ltd, ‘Durability and corrosion testing’, 2011, www.kalzip.co.uk/PDF/uk/BAM%20 Durability%20and%20corrosion%20testing.pdf (accessed September 2015). Ibid. Aluminium Alloy Manufacturing and Recycling Association, British and European Aluminium Casting Alloys, Aluminium Federation (ALFED), 2008, p 79.

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Aluminium Finishing Association, Finishing Aluminium: A Guide for Architects, 1999. Ibid. Chromate conversion coating pre-treatment is currently also used prior to the wet application of PVDF to aluminium. www.tomburn.com/case-study/5ea80a3530591/ How-many-types-of-powder-coating-are-there(accessed March 2023. http://www.interpon.com/about-us/sustainability (accessed 21 March 2023). Qualicoat, Specifcations for a Quality Label for Liquid and Powder Organic Coatings on Aluminium for Architectural Applications, 16th edition, Qualicoat, 2019. Qualicoat, ‘Recommendations for Care of Coated Aluminium’, 2011, www.qualicoat.net/ main/downloads.html (accessed August 2019). RAL is a system developed by the German State Commission for Delivery Terms and Quality Assurance (Reichsausschuß für Lieferbedingungen und Gütesicherung) to provide colour matching. If it is necessary to change the colour of a polyester powder-coated façade, say because of a change in corporate identity, it is practical to specify a wet-applied PVDF paint system; companies such as Tomburn will provide a 10-year guarantee for such a fnish. This includes a dent repair service, if required. www.rpbw.com/project/the-shard (accessed July 2017). Total solar refectance (TSR) testing to ASTM G-173 by the Faculty of Engineering, University of Porto. Qualicoat, ‘Recommendations for Care of Coated Aluminium’. http://www.axaltacs.com/gb/en_GB/powdercoatings/products/product-catalogue/ Alesta-Cool.html (accessed October 2017). Aluminium Alloy Manufacturing and Recycling Association, British and European Aluminium Casting Alloys. M Stacey and C Bayliss, ‘Aluminium and durability: Reviewed by inspection and testing’, Materials Today: Proceedings 2, 2015, pp 5088–95. M Stacey, Aluminium and Durability: Towards Sustainable Cities, 2nd edition, Cwningen Press, 2015. Ibid. Ibid. M Stacey, Aluminium and Durability. M Stacey and C Bayliss, ‘Aluminium and Durability: Reviewed by inspection and testing’. Ibid.

28 J MacQueady, ‘Gilbert Scott’s New Bodleian Library’, Architectural Review, October 1940 (ed JM Richards, under the pseudonym James MacQueady). 29 N Pevsner, ‘Oxford’, in J Sherwood and N Pevsner, Pevsner Architectural Guides: The Buildings of England, Oxfordshire, Yale University Press, 1974, p 263. 30 New Bodleian Library: Historic England List Entry Number 1390596. Historic England was formerly English Heritage. 31 Ibid. 32 J Ratclife (ed), Aluminium and Sustainability: Cradle to Cradle, Council for Aluminium in Building, 2008, p 17. 33 The test regime is set out in M Stacey and C Bayliss, ‘Aluminium and Durability: Reviewed by inspection and testing’, pp 5088–95. 34 PG Sheasby and R Pinner, The Surface Treatment and Finishing of Aluminum and its Alloys, 6th edition, ASM International & Finishing Publications, 2001, p 2. 35 Herman Miller had outgrown this facility and it is now used by a French defence contractor. 36 M Stacey, Component Design, Butterworth Heinemann, 2001, p 28. 37 1 Finsbury Avenue: Historic England Listing Number 1422594. 38 A Brookes and M Stacey, ‘Aluminium Extrusions’, Architects’ Journal, 20 November 1985, pp 152–57. A Brookes and C Grech, Building Envelope, Butterworth, 1990, pp 41–45. CHAPTER 5

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Health and Safety Executive, ‘Manual Handling Operations Regulations 1992 (as amended): Guidance on Regulations, L23’ (3rd edition), 2004. R Horden, ‘Introduction to the Aluminium Federation Conference on the Sustainability of Aluminium Products in Building and Architecture’, at the RIBA, 13 October 2004. See also R Horden, Light Tec: Towards a Light Architecture, Birkhäuser, 1995, pp 19–27. ‘Great Airlines 11: de Havilland Comet’, Flight International, 14 March 1974, www.fightglobal. com/pdfarchive/view/1974/1974%20-%200411. html (accessed March 2016). R Fitzmaurice, ‘Aluminium fight hangar for the Comet Airliner’, Architects’ Journal, 29 January 1953, pp 169–170. Ibid. Ibid. Ibid. ‘Aluminium hangar at Hatfeld’, Architect and Building News, 29 January 1953, pp 143–45.

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9 Ibid. 10 ‘Biggest aluminium building in the world will house feet of Comets’, Welwyn Hatfeld Times, Friday 16 January 1953. 11 ‘Aluminium hangar at Hatfeld’, Architect and Building News, p 143. 12 J Peter, Aluminium in Modern Architecture, Vol 1, Reynolds Metal Company, 1958, pp 154–55. 13 The Flight Test Hangar, Ofces, Fire Station and Control Tower: Historic England Listing Number: 1376561. 14 R Fitzmaurice, ‘Aluminium fight hangar for the Comet Airliner’, p 169. 15 The Flight Test Hangar, Ofces, Fire Station and Control Tower: Historic England Listing Number: 1376561. 16 During the 2004 conversion, Robert Limbrick, under advice from structural engineers Clarkebond Associates (Bristol Ofce), chose to prop the structure at one-third span, with a sliding connection. Project architect Mark Sadler advised the author that ‘the props did not actually support the roof but allow it to “bottom out” on the props under extreme snow loading’ (March 2016). 17 Eurocode 9: Design of aluminium structures, 2007, European Commission, https://eurocodes. jrc.ec.europa.eu/EN-Eurocodes/eurocode9-design-aluminium-structures (accessed June 2023). 18 https://www.lords.org/history/lordshistory/the-three-lords-grounds (accessed February 2016). 19 D Sudjic, Future Systems, Phaidon, 2006, p 187. 20 Ibid, p188. 21 M Stacey, Component Design, Architectural Press, 2001, p 90. 22 D Sudjic, Future Systems, p 201. 23 Ibid. 24 M Stacey, ‘Frozen music’, Architecture Today, AT219, June 2011, pp 12–14. 25 M Stacey, Aluminium Recyclability and Recycling: Towards Sustainable Cities, Cwningen Press, 2015, pp 234–35. 26 http://www.mvsa-architects.com/project/ detail/34/bridge-westerdok (accessed January 2016). 27 M Stacey, Aluminium: Flexible and Light: Towards Sustainable Cities, Cwningen Press, 2015. 28 Film available from British Pathe, http://www. britishpathe.com/video/aberdeen-queen-motheropens-new-bridge (accessed December 2015). 29 A de la Chevrotière, in conversation with the author, February 2016. 30 This military bridge is a development of MAADI Group’s patented weld-free civic pedestrian

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bridge range Make-A-Bridge®, funded by Canadian government research grants. AASHTO, ‘LRFD Guide Specifcation for the Design of Pedestrian Bridges’, 2009, pp 7–8. S LeBlanc, ‘Le 5 RGC teste un nouveau type de pont’, Adsum, 10 February 2016, www. journaladsum.com/news.php?id=992 (accessed February 2016). M Stacey, Aluminium Recyclability and Recycling, pp 53–63. A de la Chevrotière, in conversation with the author, February 2016. Ibid. S LeBlanc, ‘Le 5 RGC teste un nouveau type de pont’. D Beaulieu, J Internoscia and M Hartlieb, Ponts et Passerelles en Aluminium: Rapport de visites et de rencontres en Suède, en Hollande et aux États-Unis, AluQuebec and AAC, 2015, pp 6–20, https://aluminium.ca/pdf/rapport_fnal_ mission%20preparatoire_ponts_d_Alu_vf.pdf (accessed November 2015). Ibid. https://www.fhwa.dot.gov/bridge/nbi/no10/ defbr14.cfm (accessed January 2016). Deloitte, ‘Life Cycle Analysis Aluminium vs. Steel’ (PDF), 3 March 2012, p 3. M Stacey, Aluminium Recyclability and Recycling, pp 14–33. C Wilkinson and J Eyre, Bridging Art and Science: Wilkinson Eyre Architecture, Booth-Clibborn Editions, 2001, p 186. Jim Eyre, in conversation with the author, December 2015. Arup won this bridge commission in the same week that the Millennium Bridge in London, which it had designed with Foster + Partners, closed on 12 June 2000, due to excessive vibration resulting simply from pedestrian footfall. M Stacey, Concrete: A Studio Design Guide, RIBA Publishing, 2011, pp 46–51.

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‘30 St Mary Axe’ (pdf), www.fosterandpartners. com/news/archive/2004/04/30-st-mary-axelondon (accessed April 2016). http://greenbuilding.world-aluminium.org/en/ benefts/efcient/melvin-j-and-claire-levine-hall. html (accessed March 2015). S Kieran, J Timberlake and K Wallick, KieranTimberlake: Inquiry, Rizzoli International Publications, 2011, p 235. KieranTimberlake’s ‘Project Data Sheet’ for Melvin J and Claire Levine Hall, supplied to the author in 2009.

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Haydn Thomas of AHMM, speaking as one of the 16 architects who contributed to the Council for Aluminium in Building (CAB) Thames Journey, 1 October 2105, recorded by the author. Allford Hall Monaghan Morris, ‘240 Blackfriars Road Supporting Information’ (pdf), supplied to the author in September 2015. Ibid. Data provided by Haydn Thomas, Project Architect at AHMM, U-values for other elements on this project: inclined overhead roof panels, Ucw-value 1.8W/m2K, and rainscreen panels, Uw-value 0.3W/m2K. www.kierantimberlake.com/pages/view/9 (accessed March 2016). S Kieran, J Timberlake and K Wallick (2011), KieranTimberlake: Inquiry, p 248. www.kalwall.com/company/history (accessed March 2016). http://www.everymanplayhouse.com/everymanhistory (accessed March 2016). www.architecture.com/RIBA/Contactus/ NewsAndPress/PressReleases/2014/The EverymanTheatreinLiverpoolbyHaworthTom pkinsarchitectswins2014RIBAStirlingPrizefor thebestnewbuildingoftheyear.aspx (accessed March 2016). Ibid. Ibid. Ibid. Haworth Tompkins, ‘Liverpool Everyman Theatre: BREEAM Case Study’, www. haworthtompkins.com/built/proj44/drawings/ EverymanTheatre_BREEAM_CaseStudy.pdf (accessed September 2015). Ibid. www.westpier.co.uk (accessed April 2016). Guinness World Record verifed on 26 January 2016, www.guinnessworldrecords.com/worldrecords/401534-most-slender-tower (accessed April 2016). Cost data supplied by Mark Barfeld Architects to the author, September 2016, noting that this construction cost does not includes fees, interest and other related project costs. Marks Barfeld Architects conceived and designed the i360, and remain a fnancial stakeholder in the project. Ian Crockford in conversation with the author on site in Brighton, 13 April 2016. Data supplied by James and Taylor via Marks Barfeld Architects, May 2016. http://britishairwaysi360.com/latest-news/blog/ british-airways-i360-pod-is-completed (accessed April 2016). Ibid.

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C Wilkinson, Supersheds: The Architecture of Long-Span Large-Volume Buildings, Butterworth Architecture, 1991. J Paillister (ed), Hopkins Architects, London 2012 Velodrome: Design in Pursuit of Efciency, Architects’ Journal, Special Edition, 2011, p 23. www.bbc.co.uk/sport/olympics/15149865 (accessed March 2016). J Paillister (ed), Hopkins Architects, London 2012 Velodrome: Design in Pursuit of Efciency, p 38. Ibid. Ibid. Ibid. Ibid, p 47. Ibid, p 40. M Stacey, Aluminium: Flexible and Light: Towards Sustainable Cities, Cwningen Press, 2016, pp 316–19. S McLeman of Kalzip, in conversation with the author, March 2016. J Paillister (ed), Hopkins Architects, London 2012 Velodrome: Design in Pursuit of Efciency, p 44. Ibid, p 48. Ibid. (Nicolas Serota was an ODA board member and Chair of the velodrome design competition jury. He was Director of the Tate from 1988 to 2017 and is currently Chair of Arts Council England.) www.bbc.co.uk/sport/olympics/18019438 (accessed March 2016). London Aquatics Centre, http://www. zaha-hadid.com/architecture/london-aquaticscentre (accessed March 2016). S McLeman of Kalzip, in conversation with the author, March 2016. Ibid. www.lakesmere.com/Case-Study/60/ London-Aquatics-Centre/1.aspx (accessed March 2016). W Buttress (ed), BE· Hive: UK Pavilion Milan Expo 2015, Wolfgang Buttress Studio, 2015, p 6. Ibid, p 3. Ibid, pp 29–37. W Buttress, The Hive at Kew, Royal Botanic Gardens, 2016, p 9. W Buttress (ed), BE· Hive: UK Pavilion Milan Expo 2015, p 63. Ibid, p 64. Ibid, pp 80–87. W Buttress ( ed), BE· Hive: UK Pavilion Milan Expo 2015, pp 29–37. Mark Johnson, CEO of Stage One, in conversation with the author, February 2016. Ibid.

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30 http://www.stageone.co.uk/projects/ hive-uk-pavilion-milan-2015-expo (accessed February 2016). 31 Ibid. 32 W Buttress (ed), BE· Hive: UK Pavilion Milan Expo 2015, p 97. 33 M Stacey, Aluminium Recyclability and Recycling: Towards Sustainable Cities, Cwningen Press, 2015. 34 D Adjaye and P Allison (eds), David Adjaye Constructed Narratives, Lars Müller, 2017. 35 J Minutillo, ‘National Museum of African American History and Culture’, Architectural Record, 1 November 2016, https://www. architecturalrecord.com/articles/11964-nationalmuseum-of-african-american-history-and-culture (accessed February 2017). 36 Ibid. 37 ‘Only Artists: Yinka Shonibare and David Adjaye’, BBC Radio 4, 26 April 2017, transcribed by the author, www.bbc.co.uk/ programmes/b08n2y3b (accessed May 2017). 38 JS Ackerman, Palladio, Pelican Books, The Architects and Society Series, 1966. 39 The highest level of environmental accreditation in the LEED v4 (2014) rating system is Platinum. 40 For more information on high-performance concrete, see M Stacey, Concrete: A Studio Design Guide, RIBA Publishing, 2011, pp 23–28. 41 https://nmaahc.si.edu/explore/collection/ search?edan_q=Corona&edan_ local=1&op=Search (accessed February 2017). 42 M Kimmelman, ‘David Adjaye on designing a museum that speaks a diferent language’, New York Times, 21 September 2016. 43 Ibid. 44 nmaahc.si.edu/explore/building (accessed February 2017). CHAPTER 8

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Greta Thunberg, No One is Too Small to Make a Diference, Penguin Books, 2019, p 39. The UN Framework Convention on Climate Change can be downloaded via https://unfccc. int/resource/docs/2015/cop21/eng/l09r01.pdf (accessed March 2023). https://ukcop26.org/wp-content/ uploads/2021/11/COP26-Presidency-OutcomesThe-Climate-Pact.pdf (accessed March 2022). BEIS (Department for Business, Energy and Industrial Strategy), ‘2017 UK Greenhouse Gas Emissions, Provisional Figures’, 2018. S Carlisle, E Frielander and B Faircloth, Aluminium and Life Cycle Thinking: Towards Sustainable Cities, Cwningen Press, 2015, pp 82–83.

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Based on data from 2012. International Aluminium Institute, ‘Global Aluminium Mass Flow’, IAI, 2014, www.world-aluminium. org/media/fler_public/2014/06/19/ global_aluminium_mass_fow.xlsx (accessed March 2015). Aluminium for Future Generations, ‘Global Metal Flow’, http://recycling.world-aluminium. org/en/review/global-metal-fow.html (accessed March 2014). M Stacey (ed), ‘The future builds with aluminium’, http://greenbuilding.worldaluminium.org/home.html (accessed March 2014). Recycle Now, ‘Cans’, www.recyclenow. com/how_is_it_recycled/cans.html (accessed March 2014). SK Das, JAS Green and JG Kaufman (2010), ‘Aluminum recycling: Economic and environmental benefts’, Light Metal Age, February 2010, p 22, www.phinix.net/services/ Recycling/Aluminum_Recycling_Economic.pdf (accessed February 2015). European Aluminium Association/Organisation of European Aluminium Refners and Remelters Recycling Division, ‘Aluminium Recycling in Europe: The Road to High Quality Products’, EAA/OEA, 2006, p 6, http://recycling.worldaluminium.org/uploads/media/f0000217.pdf (accessed April 2014). International Aluminium Institute, ‘Aluminium Sector Greenhouse Gas Pathways to 2050’, 2021, https://international-aluminium.org/ resource/aluminium-sector-greenhouse-gaspathways-to-2050-2021 (accessed May 2022). European Aluminium, ‘Environmental Profle Report 2018’, EA, 2018, www. european-aluminium.eu/resource-hub/ environmental-profle-report-2018/ (accessed May 2022). Hydro Circal (formerly Hydro75R) EPD, https:// www.hydro.com/globalassets/download-center/ certifcates/nepd-1841-768-hydro-75raluminium-extrusion-ingot.pdf (accessed August 2022). International Aluminium Institute, ‘IAI Material Flow Model – 2021 Update’, 2021, https:// international-aluminium.org/resource/ iai-material-fow-model-2021-update (accessed March 2022). Data for 2021 supplied by the Aluminium Federation (ALFED) direct to the author. For more information on ALFED see https://alfed. org.uk (accessed March 2023). Ibid. Organisation for Economic Co-operation and Development, ‘OECD/IEA Joint Workshop on Sustainable Buildings: Towards Sustainable Use

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of Building Stock’, OECD, 2004, p 11, www. oecd.org/governance/regional-policy/35896769. pdf (accessed January 2014). M Stacey, Aluminium Recyclability and Recycling: Towards Sustainable Cities, Cwningen Press, 2015, pp 13–93. Interview with Walter Lonsinger by the author, 5 September 2019; see also www.a-u-f.com (accessed September 2019). British Standards BS 7543: 2015 Durability of Buildings and Building Elements, Products and Components, p 5. The Canadian approach is clearer; see Canadian Standard for Durability – CSA S478:19 – Durability in Buildings, which is used in LEED Canada. Pacifc Northwest National Laboratory for the US Department of Energy (2010), cited in Preservation Green Lab for the National Trust for Historic Preservation, The Greenest Building: Quantifying the Value of Building Reuse, NTHP, 2011, p 92, www.preservationnation. org/information-center/sustainable-communities/ green-lab/lca/The_Greenest_Building_lowres.pdf (accessed February 2015). Ibid. https://www.weforum.org/agenda/2022/11/ net-zero-cities-retroft-older-buildings-cop27 (accessed March 2023). United Nations Population Fund, ‘Urbanization’, www.unfpa.org/pds/urbanization.htm (accessed June 2012). United Nations, ‘Population’, 2022, www. un.org/en/global-issues/population (accessed March 2023). UMJ Boin and JA van Houwelingen, ‘Collection of Aluminium from Buildings in Europe: A Study by Delft University of Technology’, European Aluminium Association, 2004, http://recycling.world-aluminium.org/uploads/ media/_TUDelftBrochure2004.pdf (accessed April 2015). Ibid. Ibid, p 198. (The apartment building in Le Mans had an anomalous collection rate of only 31% due to all of the aluminium being in small parts and due to the equipment used by the recycling industry in Europe in 2004.) B Addis, Building: 3,000 Years of Design, Engineering and Construction, Phaidon, 2007, p 508. D Cruickshank, ‘The Dome of Discovery’, The Architectural Review January 1995 (1175), 1995, pp 80–85. ‘Front Row’, BBC Radio 4, 8 March 2011, available online at www.bbc.co.uk/programmes/ b00z6dvq (accessed December 2013).

31 32

33 34 35

36 37 38

39 40 41

42

43 44

45 46

47 48

49 50

Fragments of the aluminium cladding were also repurposed into commemorative knives. M Stacey, Aluminium and Durability: Towards Sustainable Cities, 2014, p 108. Preservation Green Lab for the National Trust for Historic Preservation, The Greenest Building: Quantifying the Value of Building Reuse, NTHP, 2011, www.preservationnation.org/informationcenter/sustainable-communities/green-lab/lca/ The_Greenest_Building_lowres.pdf (accessed February 2015). Ibid. Ibid. United Nations Educational, Scientifc and Cultural Organization, ‘Global Strategy’, http:// whc.unesco.org/en/globalstrategy (accessed January 2014). S Carlisle, E Frielander and B Faircloth, Aluminium and Life Cycle Thinking. Ibid. E Friedlander and S Carlisle, ‘The infuence of durability and recycling on life cycle impacts of window frame assemblies’, in M Baitz, C Bayliss and A Rissel-Vaccari (eds), ‘LCA of metals and metal products: Theory, method and practice’, The International Journal of Life Cycle Assessments 21(11), November 2016, pp 1645–57. TRACI 2.1 is an environmental impact assessment tool developed by US EPA. www.grenfelltowerinquiry.org.uk (accessed October 2022). A Brookes and M Stacey, ‘Overcladding: An uncertain panacea’, Architects’ Journal, 27 January 1988, pp 67–71. N Sandhu, AkzoNobel, RIBA Approved CPD, https://www.ribacpd.com/ akzo-nobel-powder-coatings/10065/ fre-performance-of-polyester-powdercoating/410600/movie (accessed June 2022). L Macfarlane of Arup Facades, in conversation with the author, 21 May 2015. J Davies (ed), Guy’s Tower: 40 Years On, Essentia Guy’s and St Thomas’ NHS Foundation Trust, 2014, p 34. Ibid, p 23. M Stacey, Aluminium and Durability: Towards Sustainable Cities, 2nd edition 2015, pp 61–63 and 160–63. United Anodisers’ Qualanod Certifcate is LN:1305, 6.10.1976 to 31.12.2016. A Charlson, Counting Carbon: Practical Approaches to Life Cycle Assessment in Facade Engineering, ICE, 2011, pp 1–13. GaBi software is supplied by Thinkstep. Ibid, p 4. Ibid, p 11.

51 www.architecture.com/knowledgeand-resources/knowledge-landing-page/ riba-stirling-prize-winner-2018 (accessed January 2019). 52 J. Astbury (15 November 2017) Architects Journal, Foster ramps it up at Bloomberg, www. architectsjournal.co.uk/buildings/a-frst-lookinside-fosters-bloomberg-european-hq ( accessed December 2017) 53 www.sasintgroup.com (accessed September 2018).

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Index

Page numbers in bold indicate fgures and tables. 1 Finsbury Avenue, London 109, 114, 115, 116, 117 30 St Mary Axe, London 150, 151–153, 151, 152, 169 240 Blackfriars Road, London 8, 156–159, 156, 158, 159 500 Park Avenue, New York 50, 50, 51 510 Fifth Avenue, New York 44, 44, 45 606 Universal Shelving System 79, 86, 87, 87 Adams, Mark 87 Adamson Associates 105–107, 105 additive manufacturing 70–71, 71 Adjaye, David 198–205, 199, 200, 201, 203, 204, 205 aerogel insulation 162, 163 afordability 177 Manor Works, Shefeld 191, 191 Olympic Aquatics Centre, London 181, 188–189, 188, 189, 190 Olympic Velodrome, London 179–186, 180, 181, 182, 183, 184, 185, 186, 187 Stratford Jubilee Line Station, London 178–179, 178, 179 Stratford Market Depot, London 177, 178 age hardening 13 aircraft and aerospace applications 6, 7, 7, 9, 10, 27, 29, 62, 63, 71, 95, 121 AIROH prefabricated houses 35–37, 36, 37 Alcoa Building, Pittsburgh, Pennsylvania 41, 42, 43, 53 Alexander, William 55 Allford Hall Monaghan Morris (AHMM) 8, 156–159, 156, 158, 159 alloys 6–13 1000 series 6, 6 2000 series 6–7, 7, 13 3000 series 7, 7 4000 series 7 5000 series 7 6000 series 7–8, 8 7000 series 9, 9, 10 8000 series 10 superplastic 62–65, 62, 63, 64 temper 11, 12 Aluminium Centenary Pavilion, Paris 38, 39, 222 aluminium extrusions 72–87 1 Finsbury Avenue, London 114, 115, 116, 117 606 Universal Shelving System 79, 86, 87, 87

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all-aluminium oil rig pedestrian bridge 11, 11, 139–140, 140 area balance 81–82, 81 Ballingdon Bridge, Sudbury 147, 147, 148, 149 Blainville Equestrian Park Bridge, Quebec 139, 139 custom dies 72–76, 76, 78, 78 design features 79, 79 die costs 78 die size 78, 80, 80 East Croydon Station, London 82–84, 83, 84, 85 extrusion process 76–78, 77, 78 Lloyd’s of London stair tread 81, 82 Loblolly House, Maryland 72, 73, 74, 75 Lockmeadow Footbridge, Maidstone 144–145, 144, 145, 146 proprietary systems 72, 73, 74, 75 Sapa aluminium bridge deck system 143, 144 stock dies 72 stock lengths 72 tolerances 82 Vague Formation Mobile Music Pavilion 65, 68, 131–133, 131, 132 weld-free prefabricated aluminium bridges 140–142, 141, 142, 143 Alvance Aluminium Group 209 Anglican Cathedral, Liverpool 165 anodising 93–97, 93, 97 1 Finsbury Avenue, London 114, 115, 116, 117 combination anodising 95 Commerzbank, Frankfurt 97, 98 electrocolour anodising 93 fre safety 224 interference anodising 93 New Bodleian Library, Oxford 109–111, 109, 110, 111 Optic Cloak, Greenwich Peninsula, London 94 recyclability 210 Thames Water Tower, London 95 Vertical Shell (art work) 95, 96 Architectural Association’s Design + Make MArch 89, 89 Architecture 00 191, 191 Arnold, Richard 179 Arup 1 Finsbury Avenue, London 114, 115, 116, 117 30 St Mary Axe, London 150, 151–153, 151, 152, 169

Ballingdon Bridge, Sudbury 147, 147, 148, 149 Guy’s Hospital Tower overcladding, London 224–229, 225, 226, 227, 228, 229 Nasher Sculpture Center, Dallas, Texas 70 Arvida Bridge, Quebec 133, 133 A|U|F 212 back pressure forming 62 Baldry, AL 22 Ballingdon Bridge, Sudbury 147, 147, 148, 149 Bankside Power Station, London 34 Barfeld, Julia 168 Barley Chalu 97 Barry, EM 134 Bassov, ND 37 Bayards 70, 129, 130, 138, 138 Bayer, Karl Josef 5 Bayer process 5 BDP Manchester 193 Beesley, Philip 66–67, 66, 67 Bennetts Associates 208, 208, 209 Blainville Equestrian Park Bridge, Quebec 139, 139 Blois, Natalie de 50 Bloomberg European headquarters, London 230, 230 Bode, Klaus 185 Bond, Max, Jr 198–205, 199, 200, 201, 203, 204, 205 BREEAM 157, 166, 216, 230 Bridge of Aspiration, Covent Garden, London 118, 134–136, 134, 135, 136, 137 bridges 133 all-aluminium oil rig pedestrian bridge 11, 11, 139–140, 140 Arvida Bridge, Quebec 133, 133 Ballingdon Bridge, Sudbury 147, 147, 148, 149 Blainville Equestrian Park Bridge, Quebec 139, 139 Bridge of Aspiration, Covent Garden, London 118, 134–136, 134, 135, 136, 137 Lockmeadow Footbridge, Maidstone 144–145, 144, 145, 146 Sapa aluminium bridge deck system 143, 144 St Clements’ Bridge, Victoria Dock, Aberdeen 138, 138 Tottnäs Bridge, Stockholm 143, 144 weld-free prefabricated aluminium bridges 140–142, 141, 142, 143 Westdork Bridge, Amsterdam 138, 138

INDEx

British Airways i360, Brighton 168–175, 168, 169, 170, 171, 172, 173, 174, 175 Brookes, Alan 41, 224 Brookes Stacey Randall Fursdon 37 Churchill Centre, Rotterdam 220, 221 East Croydon Station, London 58, 82–84, 83, 84, 85 Lowe Apartment, London 119, 119, 120 Thames Water Tower, London 95 Brunfaut, Gaston 37 bubble forming 62 Buckminster Fuller, Richard 35, 35, 52, 52, 67, 193 Bunch, Lonnie G, III 205 Bunshaft, Gordon 50 Buttress, Wolfgang 192–198, 192, 193, 194, 195, 196, 197, 198 Canadian Army Tactical Bridge 140–142, 141, 142, 143 Carlisle, Stephanie 222 Carson, Pirie, Scott and Company Store, Chicago 200 Catholic Metropolitan Cathedral, Liverpool 165 cavity forming 62, 63 Centre Pompidou, Paris 199 CF Møller Architects 94 Charlson, Andrea 228 chromate conversion coating 99 chromium 9 Church of St Edmund, King and Martyr, Fenny Bentley, Derbyshire 17–18, 17 Churchill Centre, Rotterdam 220, 221 circumscribing circle diameter (CCD) 78, 79, 80, 81 cleaning 92, 92 climate change 207, 231 see also sustainability Climatron, St Louis, Missouri 52, 52 cold rolling 56 cold working 11, 12 combination anodising 95 Comet Flight Test Hangar, Hatfeld, Hertfordshire 121, 122, 123–127, 124, 125, 126, 127 Commerzbank, Frankfurt 97, 98 Constellium 78 copper 6, 9, 13, 90 Cormier, Ernest 37 corrosion 90–92, 91, 92 Council for Aluminium in Building (CAB) 212 crabbing 57 Crockford, Ian 175 cultural heritage 220 Davy, Sir Humphry 5 de Havilland, Sir Geofrey 121, 124, 125 de la Chevrotière, Alexandre 142 design for assembly (DfA) 142 design for disassembly (DFD) 87, 142, 198 Diane de Gabies (sculpture) 24, 24 diaphragm forming 62, 63 Dome of Discovery, Festival of Britain, London 216–218, 217, 218, 219

durability 89–92, 91, 92, 95, 109, 117, 208, 214–215, 214, 224 1 Finsbury Avenue, London 114, 115, 116, 117 Herman Miller Distribution Centre, Chippenham 112, 112, 113 New Bodleian Library, Oxford 109–111, 109, 110, 111 Nuremberg Congress Hall 90 duraluminium 13 Dwight, John 13 Dymaxion House, Wichita, Kansas 35, 35 East Croydon Station, London 58, 82–84, 83, 84, 85 electrocolour anodising 93 Empire State Building, New York 32, 32, 33, 200 Environmental Product Declaration (EPD) 208 Eros (sculpture) 24, 24, 90 Erskine, Alice M 17, 18 Everyman Theatre, Hope Street, Liverpool 164–167, 164, 165, 166, 167 Expedition Engineering 179, 180 extrusions see aluminium extrusions Eyre, Jim 134, 135, 144–145 fabrication processes additive manufacturing 70–71, 71 back pressure forming 62 bubble forming 62 cavity forming 62, 63 cold rolling 56 diaphragm forming 62, 63 extrusion process 76–78, 77, 78 forming sheet aluminium 54, 56 friction stir welding (FSW) 69–70, 69, 70 hand forming 56 hot rolling 54, 56 laser cutting 66–67, 66, 67 milling, machining and cutting 65–67, 65, 66, 67 press braking 57–59, 58, 59 pressing and stamping 56 roll forming 57, 57, 58 spinning 59–60, 59, 60, 61 superplastic alloys 62–65, 62, 63, 64 waterjet cutting 67 welding 68–70, 68, 69, 70, 130 Federation Nationale du Bâtiment Ofces, Paris 37 Feilden Clegg Bradley Studios 213 Financial Times Printworks, London 108 fnishes 92 see also anodising; polyester powder coating (PPC); polyvinyl fuoride coatings (PVDF) fre safety 224 Fitzmaurice, R 123 Flint & Neill 118, 134–136, 134, 135, 136, 137 Foster + Partners 30 St Mary Axe, London 150, 151–153, 151, 152, 169 Bloomberg European headquarters, London 230, 230 Commerzbank, Frankfurt 97, 98 Sainsbury Centre for Visual Arts, University of Norwich 64–65, 64

Freelon, Philip 198–205, 199, 200, 201, 203, 204, 205 Freeman Fox and Partners 216–218, 217, 218, 219 friction stir welding (FSW) 69–70, 69, 70 Friedlander, Efrie 222 Future Systems Lord’s Media Centre, St John’s Wood, London 128–131, 128, 129, 130 Selfridges Department Store, Birmingham 59, 60, 60, 61 Gatwick North Piers 63 General Motors Technical Center, Warren, Michigan 40–41, 40 Ghent Velodrome 179 Gibberd, Sir Frederick 165 Gideon, Siegfried 29 Gilbert, Alfred 24 Gilbert Scott, Sir Giles 34, 34, 109–111, 109, 110, 111, 165 Green Industrial Revolution 231, 231 Guy’s Hospital Tower overcladding, London 224–229, 225, 226, 227, 228, 229 Hall, Charles Martin 5 Hall-Heìroult electrolysis process 5 Hall, Julia Brainerd 5 hand forming 56 Harrisburg West Interchange Turnpike Booths, Pennsylvania 41 Harrison & Abramovitz Alcoa Building, Pittsburgh, Pennsylvania 41, 42, 43, 53 UN Secretariat Building, New York 37–38, 38 Haworth Tompkins 164–167, 164, 165, 166, 167 Head, Wrightson & Co 138, 138 heat-treatable alloys 10–11 heat treatment 11, 12 Heelis National Trust Headquarters, Swindon 213 Heìroult, Paul 5 heritage value of architecture 220 Herman Miller Distribution Centre, Chippenham 56, 112, 112, 113 Herzog & de Meuron 192 history of aluminium 5, 6, 14–15 Hive pavilion, Milan Expo 192–198, 192, 193, 194, 195, 196, 197, 198, 222 Holiday Inn Express, Nottingham 92 Hopkins Architects 128, 179–186, 180, 181, 182, 183, 184, 185, 186, 187 Horniman Museum, London 22 hot rolling 54, 56 Houldcroft, Peter 66 hydroelectricity 207, 208–209, 208 IBM exhibition pavilion 133 in-use benefts 222, 223 Ingami, Rafaele 16, 18, 19, 20–21 interference anodising 93 iron 9 Irvine, Max 175 Ive, Jonathan 87

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James M Monro & Son 121, 122, 123–127, 124, 125, 126, 127 Jones, Michael 230 Josef Gartner 114, 115, 116, 117 Kalwall 161, 162, 163 Kalzip 90, 91, 178, 183, 188–189 Kaplicky, Jan 128–131, 128, 129, 130 Keller, Robert R 162 KieranTimberlake Loblolly House, Maryland 72, 73, 74, 75 Melvin J and Claire Levine Hall, University of Pennsylvania, Philadelphia 153–155, 153, 154, 155 Yale University Sculpture Building, New Haven, Connecticut 159–162, 160, 161, 162, 163 King, Martin Luther, Jr 205 Kinnock, Neil 37 Kirtley, Toby 110 Kistler, Samuel S 162 Krasevac, Branko 213, 213 Kraševac, Branko 53, 53 Lamb, William F 32, 32, 33, 200 laser cutting 66–67, 66, 67 Le Corbusier 37 Lever House, New York 37 Lewerentz, Sigurd 165 Liang Seu-Cheng 37 Life Cycle Assessment (LCA) 144, 208, 211, 222, 223, 228 lightness and strength 119 Comet Flight Test Hangar, Hatfeld, Hertfordshire 121, 122, 123–127, 124, 125, 126, 127 Lord’s Media Centre, St John’s Wood, London 128–131, 128, 129, 130 Lowe Apartment, London 119, 119, 120 Ski Haus 121, 121 Vague Formation Mobile Music Pavilion 65, 68, 131–133, 131, 132 see also bridges Ljubljana Television Centre, Ljubljana, Slovenia 213, 213 Lloyd’s of London 81, 82 Loblolly House, Maryland 72, 73, 74, 75 Lochaber smelter, Fort William 209 Lockmeadow Footbridge, Maidstone 144–145, 144, 145, 146 London Eye 168–169 Lonsinger, Walter 212 Lord’s Media Centre, St John’s Wood, London 128–131, 128, 129, 130 Lovell Health House, Los Angeles 119 Lowe Apartment, London 119, 119, 120 MAADI Group all-aluminium oil rig pedestrian bridge 11, 11, 139–140, 140 Blainville Equestrian Park Bridge, Quebec 139, 139 weld-free prefabricated aluminium bridges 140–142,

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141, 142, 143 Macfarlane, Laura 226 magnesium 7, 9, 13 Maier, Joachim 76 Maiman, Ted 66 manganese 7, 9, 13 Manor Works, Shefeld 191, 191 Manufacturers Hanover Trust Company Bank, New York 44, 44, 45 Markelius, Sven 37 Marks Barfeld Architects 168–175, 168, 169, 170, 171, 172, 173, 174, 175 Marks, David 168 Melvin J and Claire Levine Hall, University of Pennsylvania, Philadelphia 153–155, 153, 154, 155 Metalka Building, Ljubljana, Slovenia 53, 53 Michael Stacey Architects 109 Ballingdon Bridge, Sudbury 147, 147, 148, 149 Sophos Operational Headquarters, Abingdon, Oxfordshire 208, 208, 209 Mies van der Rohe, Ludwig 53 MIG (Metal Inert Gas) welding 69 Mihevc, Edo 53, 53 Mills, Robert 200 Minutillo, Josephine 198 Morris + Company 103, 104, 105, 105 Murphy and Mackey 52, 52 Museum of Welsh Life, St Fagans, Cardif 35–37, 36, 37 MVSA Architects 138, 138 Nash, John 58 Nasher Sculpture Center, Dallas, Texas 70 Nematox II node 71, 71 neoprene gaskets 40–41, 52, 112 Neutra, Richard 119 New Bodleian Library, Oxford 34, 109–111, 109, 110, 111 Nicholas Grimshaw & Partners Financial Times Printworks, London 108 Herman Miller Distribution Centre, Chippenham 56, 112, 112, 113 Sainsbury’s supermarket, Camden, London 63 Niemeyer, Oscar 37 non-heat-treatable alloys 10–11 Nuremberg Congress Hall 90 Olympic Aquatics Centre, London 181, 188–189, 188, 189, 190 Olympic Stadium, London 179 Olympic Velodrome, London 179–186, 180, 181, 182, 183, 184, 185, 186, 187 Optic Cloak, Greenwich Peninsula, London 94 Ørsted, Hans Christian 5 overcladding 224–229, 225, 226, 227, 228, 229 Palladio, Andrea 199 Paoletti, Roland 178 Parks, Leslie 76 Paul Morin & Cie 24, 24

pavilions 38 Aluminium Centenary Pavilion, Paris 38, 39, 222 Hive pavilion, Milan Expo 192–198, 192, 193, 194, 195, 196, 197, 198, 222 IBM exhibition pavilion 133 Vague Formation Mobile Music Pavilion 65, 68, 131–133, 131, 132 Penoyre and Prasad Architects 224–229, 225, 226, 227, 228, 229 performative façades 30 St Mary Axe, London 150, 151–153, 151, 152, 169 240 Blackfriars Road, London 8, 156–159, 156, 158, 159 British Airways i360, Brighton 168–175, 168, 169, 170, 171, 172, 173, 174, 175 Everyman Theatre, Hope Street, Liverpool 164–167, 164, 165, 166, 167 Melvin J and Claire Levine Hall, University of Pennsylvania, Philadelphia 153–155, 153, 154, 155 Yale University Sculpture Building, New Haven, Connecticut 159–162, 160, 161, 162, 163 Permasteelisa 154, 155, 226–227 Peter, John 124 Pevsner, Nikolaus 25, 109–110 Piano, Renzo 70, 105–107, 106, 133, 199 polyester powder coating (PPC) 97, 99–102, 99, 100, 101 durability 102, 102, 112, 112, 113, 114, 117 fre safety 224 Herman Miller Distribution Centre, Chippenham 112, 112, 113 pre-treatment 99, 101 R7, King’s Cross, London 103, 104, 105, 105 recyclability 210 Shard, London 105–107, 106 polyvinyl fuoride coatings (PVDF) 107, 108, 117, 224 Populous 179 Postsparkasse, Vienna 25–31, 25, 26, 27, 28, 29, 30 Powell and Moya 217, 218 power mix used to produce aluminium 207, 208–209, 208 PPC see polyester powder coating (PPC) prefabrication advantages 121 AIROH prefabricated houses 35–37, 36, 37 all-aluminium oil rig pedestrian bridge 11, 11, 139–140, 140 Blainville Equestrian Park Bridge, Quebec 139, 139 Bridge of Aspiration, Covent Garden, London 118, 134–136, 134, 135, 136, 137 British Airways i360, Brighton 168–175, 168, 169, 170, 171, 172, 173, 174, 175 Comet Flight Test Hangar, Hatfeld, Hertfordshire 121, 122, 123–127, 124, 125, 126, 127 Lord’s Media Centre, St John’s Wood, London 128–131, 128, 129, 130 Lowe Apartment, London 119, 119, 120 Ski Haus 121, 121

INDEx

Vague Formation Mobile Music Pavilion 65, 68, 131–133, 131, 132 weld-free prefabricated aluminium bridges 140–142, 141, 142, 143 Westdork Bridge, Amsterdam 138, 138 press braking 57–59, 58, 59 pressing 56 Price & Myers 96 Protocell Mesh (installation) 66–67, 66, 67 Prouve, Jean 37, 38, 39, 222 Putrih, Tobias 96 PVDF see polyvinyl fuoride coatings (PVDF) R7, King’s Cross, London 103, 104, 105, 105 Rams, Dieter 79, 86, 87, 87 recyclability 209–213, 210, 211, 212, 213, 215–218, 215, 216 relocation 222 reuse 220–222, 221 Reynolds Metals Company ofce, Richmond, Virginia 45, 46, 47 Reynolds Metals Regional Sales Ofce, Southfeld, Michigan 45, 48, 49 Reynolds-Stevens, Sir William 22, 23 RIBA Stirling Prize 110, 131, 167, 230 Richard Horden Architects 121, 121 Richard Rogers Partnership 81, 82 Richards, JM 109 Rihtar, France 213, 213 Roberts Limbrick Architects 126, 127 Robertson, Howard 37 Rogers, Richard 199 roll forming 57, 57, 58 Royal Botanic Gardens, Kew, London 198, 198 Royal Pavilion, Brighton 58 Rural Design 88, 89 Rutzinger, Stefan 131–133, 131, 132 Saarinen, Eero 40–41, 40 Sainsbury Centre for Visual Arts, University of Norwich 64–65, 64 Sainsbury’s supermarket, Camden, London 63 Sainsbury’s supermarket, Greenwich, London 216 St Clements’ Bridge, Victoria Dock, Aberdeen 138, 138 St Mary the Virgin, Great Warley, Essex 22, 22, 23 St Peter’s Church, Klippan, Sweden 165 San Gioacchino, Rome 16, 18, 19, 20–21 Sapa aluminium bridge deck system 143, 144 Sawmill Shelter, Hooke Park, Dorset 89, 89 Schimkowitz, Othmar 27, 29 Schinegger, Kristina 131–133, 131, 132 Schüco 8, 65, 160, 162, 212 Schumacherwerder Overseas Centre, Hamburg 91 Seagram Building, New York 53 Selfridges Department Store, Birmingham 59, 60, 60, 61 service life of buildings 214–215, 214 Shard, London 105–107, 106, 169 Shawcross, Conrad 94 Shreve, Lamb & Harmon 32, 32, 33, 200

Sidor, Neven 112 silicon 7, 9 Simmonds, Tristan 193 Skerrey, EW 18 Ski Haus 121, 121 Skidmore, Owings & Merrill Lever House, New York 37 Manufacturers Hanover Trust Company Bank, New York 44, 44, 45 Reynolds Metals Company ofce, Richmond, Virginia 45, 46, 47 World Headquarters of the Pepsi-Cola Company, New York 50, 50, 51 Skylon, Festival of Britain, London 217, 218 SmithGroupJJR 198–205, 199, 200, 201, 203, 204, 205 Smithsonian National Museum of African American History and Culture (NMAAHC), Washington, DC 198–205, 199, 200, 201, 203, 204, 205 Soilleux, GA 37 soma 65, 68, 131–133, 131, 132 Sophos Operational Headquarters, Abingdon, Oxfordshire 208, 208, 209 South Bank Tower, London 96 spinning 59–60, 59, 60, 61 Stage One 193–196, 194, 195, 196 stamping 56 Stratford Jubilee Line Station, London 63, 178–179, 178, 179 Stratford Market Depot, London 177, 178 Strauss, Holger 71 Street, Arthur 55 Sudjic, Deyan 128, 131 Sullivan, Louis 200 superplastic alloys 62–65, 62, 63, 64 sustainability 207–231, 231 collection of aluminium from demolished buildings 215–218, 215, 216 fre safety 224 overcladding 224–229, 225, 226, 227, 228, 229 power mix used to produce aluminium 207, 208–209, 208 recyclability 209–213, 210, 211, 212, 213, 215–218, 215, 216 relocation 222 reuse 220–222, 221 service life of buildings 214–215, 214 in-use benefts 222, 223 Svensson, Lars 143, 144 Tabor, Jan 31 Taylor, Mike 180 temper 11, 12 Thames Water Tower, London 95 thermoplastics 99 thermosetting coatings 99 Thomas, Haydn 156 Thomas, Wayne M 69–70 Thunberg, Greta 207 TIG (Tungsten Inert Gas) welding 68–69, 130

Tin House, Isle of Skye 88, 89 Tottnäs Bridge, Stockholm 143, 144 Townsend, Charles Harrison 22, 22, 23 Trefois, MJ 179 Tubbs, Ralph 216–218, 217, 218, 219 UN Secretariat Building, New York 37–38, 38 United Anodisers 97, 228 University of Cambridge Library 34, 34 Vague Formation Mobile Music Pavilion 65, 68, 131–133, 131, 132 Verity, Thomas 128 Vertical Shell (art work) 95, 96 Vilamajó, Julio 37 Villa Rotunda, Vicenza 199 Vitsoe + Zapf 86, 87 Wagner, Otto 25–31, 25, 26, 27, 28, 29, 30 Washington Monument 24, 24, 200, 204 waterjet cutting 67 Watkins Gray Architects 224, 226 weathering 90–92, 91, 92 WEFA 76, 76, 78 welding 68–70, 68, 69, 70, 130 The Welding Institute (TWI) 69–70 Wembley Stadium, London 215, 216 Westdork Bridge, Amsterdam 138, 138 Weston Library, Oxford 110, 110 White House, Washington, DC 199 Whitechapel Art Gallery, London 22 Wilkinson, Chris 178 WilkinsonEyre Bridge of Aspiration, Covent Garden, London 118, 134–136, 134, 135, 136, 137 Lockmeadow Footbridge, Maidstone 144–145, 144, 145, 146 Stratford Jubilee Line Station, London 63, 178–179, 178, 179 Stratford Market Depot, London 177, 178 Weston Library refurbishment, Oxford 110, 110 Wilm, Alfred 13 Winged Victory (sculpture) 27, 29 Wise, Chris 180 Wöhler, Friedrich 5 World Headquarters of the Pepsi-Cola Company, New York 50, 50, 51 Wright Flyer (aircraft) 27, 29 Yale University Sculpture Building, New Haven, Connecticut 159–162, 160, 161, 162, 163 Yamasaki, Minoru 45, 48, 49 Young, John 82 YRM 63 Zaha Hadid Architects 181, 188–189, 188, 189, 190 zinc 9

2 41

Image Credits

Fig 0.1 Richard Bryant; 1.1, 2.43, 3.2, 3.11, 3.19, 3.33, 3.37, 3.38, 3.41, 3.42, 4.8, 4.11, 6.2, 6.3, 6.4, 6.5, 6.6, 6.7, 6.20, 6.24, 6.25, 6.26, 6.27, 6.28, 6.29, 7.33 Michael Stacey Architects; 1.2, 1.3, 1.5, 1.10, 1.13, 2.1, 2.3, 2.5, 2.6, 2.7, 2.10, 2.11, 2.12, 2.13, 2.15, 2.17, 2.18, 2.21, 2.22, 2.24, 2.26, 2.28, 3.5, 3.7, 3.12, 3.14, 3.16, 3.28, 3.31, 4.6, 4.7, 4.9, 4.10, 4.15, 4.24, 4.27, 4.28, 4.30, 4.33, 4.34, 4.35, 4.36, 5.8, 5.11, 5.12, 5.13, 5.22, 5.46, 5.47, 5.48, 5.49, 5.50, 6.19, 6.22, 6.30, 6.31, 7.8, 7.20, 7.21, 7.34, 7.35, 7.36, 7.38, 7.39, 7.41, 8.5, 8.6, 8.10, 8.12, 8.27 Author; 1.4 Ed Coates Collection (image courtesy of the Ed Coates Collection); 1.6 © Audi; 1.7, 6.8 © Tim Soar; 1.8 © Schüco; 1.9 © Apple, Inc.; 1.11 Master Films - P. Pgeyre / IAI; 1.12, 5.34, 5.35, 5.36, 5.37, 5.38, 5.39, 5.40 MAADI Group; 2.2 Jenny Grewcock; 2.4 Benjamin Stanforth; 2.8 Aluminium Federation; 2.9 Theodor Horydczak; 2.14, 7.37 Library of Congress; 2.16, 2.25, 2.45, 4.25 RIBA Collections; 2.19 Shreve, Lamb & Harmon; 2.20 Roland Holbe/Artur/ View; 2.23 Stanford University; 2.27, 2.42 Chantelle Niblock; 2.29, 2.34, 2.37, 2.41 Ezra Stoller/Esto; 2.30, 2.33 Stephanie Carlisle; 2.31, 2.32 Library and Archive Division, Historical Society of Western Pennsylvania; 2.35, 2.36, 2.44 Chantelle Niblock; 2.38 SOM; 2.39, 2.30 Balthazar Korab; 2.46, 8.9 Ron Fitch; 3.1 Michel Denance; 3.3, 3.4 3.6 AME; 3.8 John Cherrey; 3.9, 3.10, 5.14, 5.15 Future Systems; 3.13, 8.26 Foster + Partners; 3.15, 3.18 soma; 3.17 Philip Beesley; 3.20, 3.21 TWI; 3.22, 3.23 Holger Strauss; 3.24 Barry Halkin; 3.25, 3.26, 6.11, 6.12 Peter Aaron; 3.27, 3.30 WEFA; 3.29, 8.15 Architectural Press Archive / RIBA Collections; 3.32 Aluminium Shapes; 3.34 John Young; 3.35 Richard Rogers + Partners; 3.36, 8.16A, 8.16B BSRF; 3.39, 3.40 ©

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Vitsoe; 4.1 Rural Design Architects; 4.2 Architectural Association; 4.3 German Federal Institute for Materials Research and Testing (BAM); 4.4 RM Rostron/Michael Stacey; 4.5 K Barton/Michael Stacey; 4.12 Ron Bambridge; 4.13 Barley Chalu; 4.14 Ian Lambot; 4.16 Courtesy of Nordson; 4.17, 4.18 Powedertech; 4.19 Image courtesy of Qualicoat; 4.20, 4.21, 4.22 Duggan Morris; 4.23, 7.2, 7.4, 7.5, 8.18, 8.25 Dennis Gilbert; 4.26, 5.1, 5 .25, 5.26, 5.27, 5.28, 5.29, 5.30, 5.42, 5.43, 5.44, 6.9, 7.3 WilkinsonEyre; 4.29 Nicholas Grimshaw and Partners; 4.31 Ben Stanforth; 4.32 Valspar; 5.3 HSE; 5.2, 5.4, 5.5 Brookes Stacey Randall Fursdon; 5.6 Richard Horden Architects; 5.7 Wilfrid Collis / RIBA Collections; 5.9, 6.14, 8.1, 8.13 John Maltby / RIBA Collections; 5.10 Roberts Limbrick Architects; 5.16, 5.17 Bayards; 5.18 Daniel Thistlethwaite; 5.19, 5.20, 5.21 F Hafele; 5.23 Nick Wood; 5.24 Jim Eyre/WilkinsonEyre; 5.31, 5.32 MVSA Architects; 5.33 British Pathe; 5.41 Lars Svensson of Sapa; 5.45 Simon Warren; 6.1 Pawel Libera / RIBA Collections; 6.10 AHMM; 6.13, 6.15, 6.16, 6.17, 8.3, 8.7, 8.17 KieranTimberlake; 6.18, 6.21 Philip Vile; 6.23 EAA; 7.1 NASA; 7.6 Edmund Sumner; 7.7, 7.9, 7.10, 7.11, 7.13 Hopkins Architects; 7.12 © hiphopislanddotcom; 7.14 © Royal Mail; 7.15 Richard Davies; 7.16, 7.17, 7.19, 7.32 Hufton + Crow; 7.18 Lakesmere; 7.22, 7.25, 7.26 Courtesy of UKTI; 7.23, 7.28, 7.29, 7.30 Wolfgang Buttress Studio; 7.24 Laura Gaskell; 7.27 Fahad Mohammed; 7.31 Tim Leigh; 7.40 Jinlong Marshall Wang; 8.2, 8.8 IAI / Michael Stacey Architects; 8.4 Bennetts Associates; 8.11 Heathrow Photo Library; 8.14 Jonathan Tubbs; 8.19 Essentia; 8.20 Penoyre & Prasad; 8.21, 8.23 Michael Ramwell; 8.22 Philip Noone; 8.24 Arup Facades;