Building in Timber - Room Modules 9783955534950, 9783955534943

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Building in Timber

 Room Modules Wolfgang Huß Matthias Kaufmann Konrad Merz

∂ Practice

Building in Timber

 Room Modules Wolfgang Huß Matthias Kaufmann Konrad Merz

∂ Practice

Authors Wolfgang Huß Matthias Kaufmann Konrad Merz Advice on special questions: on “Background Vorarlberg”, “Architecture”: Johannes Kaufmann, Johannes Kaufmann GmbH, Dornbirn / Vienna (AT) on “Background Switzerland”, “Room modules as frame structures”, “Digitisation /Automisation”: Patrick Suter, Erne AG Holzbau, Laufenburg (CH) on “Questions of transport”: Reinhard Hämmerle, Hämmerle Spezialtransporte GmbH, Hard am Bodensee (AT) on “Development in Germany”: Claus Holtmann, Holtmann Messebau GmbH & Co. KG, Langenhagen (DE)

Publisher Editing: Steffi Lenzen (Project management); Claudia Fuchs, Eva Schönbrunner Editorial team: Michaela Linder, Lena Stiller, Heike Werner; Carola Jacob-Ritz Cover design following a concept by Kai Meyer, Munich Drawings: Ralph Donhauser, Marion Griese, Barbara Kissinger, Irini Nomikou, Eva Schönbrunner, Nursah Tanritanir Translation into English: Julian Jain, Berlin Copy-editing (English edition): Stefan Widdess, Berlin Proofreading (English edition): Meriel Clemett, Bromborough, UK © 2019 DETAIL Business Information GmbH, Munich An Edition DETAIL book ISBN 978-3-95553-494-3 (Print) ISBN 978-3-95553-495-0 (E-book) Printed on acid-free paper made from cellulose bleached without the use of chlorine. This work is copyright-protected. The rights arising from this copyright are reserved, especially the rights of translation, reprinting, presentation, extraction of illustrations and tables, b ­ roadcasting, microfilming or reproduction by any other means, and storage in data-­processing systems, in whole or part. Reproduction of this work, or of parts thereof, even on an individual basis, is permitted only under the provisions of the copyright law in its current version. It is categorically liable for payment. Infringements are subject to the legal sanctions of the copyright law. This reference book takes into consideration the terms valid at the time of the editorial d ­ eadline and the state of the art at this point in time. Legal claims cannot be derived from the content of this book. Typesetting & production: Simone Soesters Printed by: Grafisches Centrum Cuno GmbH & Co. KG, Calbe 1st edition, 2019 This book is also available in a German-language edition (ISBN 978-3-95553-436-3). Bibliographical information of the German National Library The German National Library lists this publication in the German National Bibliography; d ­ etailed bibliographical data is available on the internet under http://dnb.d-nb.de. DETAIL Business Information GmbH Messerschmittstr. 4, 80992 Munich, Germany Tel: +49 89 381620-0 detail-online.com

Contents

  6   8   16   26   36  50   62

Preface

  66   69   72   74   77   80   84   86   89   92   94   97 100 102

Project Examples Hotel Ammerwald near Reutte Residential and Care Home with a Nursery in Fieberbrunn Hotel Katharinenhof in Dornbirn Student Hostel in Heidelberg Treet Residential Tower in Bergen Woodie Student Hostel in Hamburg Senior Citizens’ Home in Hallein Puukuokka Residential Complex in Jyväskylä Residential Complex in Toulouse “Wohnen 500” Residential Complex in Mäder Refugee Accommodation in Hanover Modular Schools in Zurich Office Building in Wabern European School in Frankfurt am Main

Fundamentals Development Design and Typology Constructing with Timber Layers, Shell and Technology Process Decision Aid: Pros and Cons of Room Module Construction

Appendix 107 Authors 108 Literature 108 Picture Credits 110 Subject Index

Preface

Why use timber room modules for building?

Multi-storey construction using room modules made of timber has more strongly come to the fore in construction processes in the last two decades, thanks to both outstanding examples as well as its potential. The reasons for this development are multilayered: Timber construction has been witnessing a continuous boom for years, especially due to its ecological qualities. The techno­ logical options offered by prefabricated timber construction are constantly being ­extended, and the hitherto patchy digital chain comprising design, construction planning and fabrication is being completed. At the same time, the global trend of ­urbanisation is continuing, connected to the demand for preferably swiftly available housing space as well as the desire for low-emission and “fast” construction projects, completed as quickly as possible in the cities. The scarce supply of urban housing is exacerbated by high migration ­dy­namics and expected changes in ­demographic profiles in future, as well as the growing demand for residential space due to changing comfort requirements. These have been steadily rising in Europe since the mid-20th century, simultaneously increasing calls for cost-efficient building. Greater industrialisation and modularisation is generally seen as embodying a large potential for cost reductions in the building industry. Timber room modules offer interesting approaches for all these topics.

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 esidential complex in Jyväskylä (FI) 2016, R ­OOPEAA

Flexibility represents the main advantage of timber room modules compared to modular constructions made of other materials: The low weight of timber as a material permits transportation of relatively large units. The largely automated framing of the timber and the type of ­joinery enable economical fabrication even of smaller quantities and, to a cer-

tain extent, the constructional variation of the individual modules. In contrast to building with room modules made of reinforced concrete, there are no restrictions due to transport weight. Moreover, the effort required for the construction of formwork, which only becomes econom­ ical at relatively high repetition factors, can be dispensed with. The inbuilt double shells of the wall and ceiling constructions at best do not represent an unnecessary additional outlay but an efficient strategy for ensuring high soundproofing. Moreover, the timber construction sector is traditionally geared towards prefabricated building. Timber construction companies today can obtain indi­ vidually prefabricated building components from manufacturers, keeping the investment requirement for commencing fabrication of room modules comparatively low. For architects, timber has great architectural potential, offering the possibility of designing both the building shell and the furnishings in a matching materiality with a high haptic and atmospheric quality. Scope and definitions This book restricts itself to the examin­ ation of multistorey room module-based buildings using timber and hybrid construction with a high architectural quality. In all examples presented, the construction method was selected on a ­project-specific basis because architects and specialist planners viewed room modules employing timber or hybrid ­construction as being the best solution for the specific building task. Not included are buildings that are directly offered to end clients as finished products by system manufacturers. Due to lacking customisation and regard for specific conditions, these finished products are, in fact, to be viewed critically.

Similarly, “architecture” made of converted standard containers is not considered in the book. The term “room module construction” is to be preferred to its counterpart “modular construction”, which, though often used in practice, can be misleading, for the latter term may also be employed for the application of planar building components, since the Latin term “modulus”, in its original meaning, merely denotes the dimensional unit, from which – as in this case – a building is formed. The often used term “cubicle” is broadly equivalent to “room module”, however, it hardly conveys the openness and vari­ ability of the design strategies and constructions. About the book The present book aims to document the constructional quality and artistic possi­bilities of building with room modules made of timber on the basis of ­outstanding built examples. It describes the currently common typologies and, more­over, provides an impetus for further developments. The structural and constructional principles have been systematically treated, demonstrating that the entire range of modern timber components is available for building with room modules. A separate chapter is dedicated to the process: from the commissioning of the planning team to the prefabrication in the workshop – representing an intermediate area between industry and craftsmanship – to the assembly of the room modules on site. This publication is the result of the collaboration between an architect, a timber construction engineer and a timber building contractor, the main protagonists for a successful construction project, and represents an attempt to perceive this topic in a holistic and an integrative manner.

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8

Development

Development

1 1896: The first room module – a by-product of the industrialisation of concrete construction

As industrialisation also increasingly impacted the building industry in the second half of the 19th century, timber as a material initially only played a subordin­ate role. In Europe, steel and reinforced concrete are the materials on which the major developments in prefabrication are based. Alongside a series of systems for planar precast concrete elements, spatial building components were also created. In 1896, the French firm Hennebique produced what is presumed to be the first concrete room module in the form of a serially manufactured signalman’s house (Fig. 1). The first half of the 20th century passed without any further noteworthy development in room module construction. In 1930, Konrad Wachsmann, the pioneer of industrially prefabricated timber construction, described the experiences he gained with prefabricated timber frame components at the company Christoph & Unmack in the book Holzhausbau – Technik und Gestaltung [“Timber house construction – technology and design”] [1]. However, spatial prefabrication remained unmentioned in this work. In 1941, Wachsmann, together with Walter Gropius, developed the General Panel System in the USA, envisaged as a purely planar prefabricated house system. He ­described it, along with many other new system developments of various building materials, in his 1959 publication Wende­ punkte im Bauen [“Turning points in construction”] [2]. Neither is there any reference to spatial prefabrication here. 1960s /1970s: Room module euphoria

Significant developments in room module construction took place in the second half of the 20th century. Industrial building methods generally gained in importance, owing to both technical achievements

and civic enthusiasm for technological innovations. At universities, the topic of the cubicle is systematically examined in a series of dissertations and publications. Depending on the politico-geographical context, very different motivations, constructions and materials played a role: in the USA, from the 1960s onwards, besides high-rise buildings comprising room modules of reinforced concrete (Fig. 2), timber room modules were also used. The so-called Mobile Homes, which were a combination of a caravan and a bungalow, became a driving force and were marketed in large numbers. Up to that point, multistorey buildings of timber modules did not exist. Around the same time, reinforced concrete was being experimented with in the Soviet Union. Already in the mid-1950s, and owing to a decision by the Central Committee of the Communist Party, serious consideration was given to room module construction and, from 1959 onwards, five- to nine-storey prototypes, too, were built. The pragmatic objective of these efforts was to examine this construction method in comparison with the parallel development of prefabricated concrete slab construction, with regard to effectivity and economic aspects. Cubicles up to 5 m wide were produced, with transportation taking place at night on closed roads. In Central Europe room module construction of reinforced concrete also played an important role following the World War II. In Switzerland, for example, the architect and entrepreneur Franz Stucky developed the Variel System (Fig. 3) with his company Elcon from 1961 onwards, based on a first patent from 1954 [3]. The three-dimensional, open space system was extendable both in the vertical and horizontal plane. It was equally employed in residential, school and office buildings,

2 1 2 3

Shifting of a Hennebique house, 1896  oom modules of reinforced concrete, hotel, R San Antonio (US) 1967/1968 Variel system by Franz Stucky

A B C D l

3

Base plate Frontal frame Roof plate Suspended ceiling =L  engths 9,600, 8,400 mm b = Width 2,790 mm b' = A  xial dimension 2,800 mm

r

=F  rame height 3,025 mm r' = 3,188 mm r'' = 3,675 mm h =C  learance height 2,494 mm h' = 2,981 mm h'' = 3,185 mm

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Development

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and was even produced under licence in North Africa as well as South America. In Japan, in the 1970s, there was great interest in futuristic-looking, large-scale structures comprising room modules. Access towers of reinforced concrete were combined with room modules comprising steel frame structures, which were partly clad in non-load-bearing plastic shells. These projects – in contrast to the purely rational considerations of the Eastern bloc – evince an aesthetic desire for an innovative and contemporary lifestyle (Fig. 6). Self-supporting plastic modules in sandwich construction (Fig. 4) were also tested. This application is mostly limited to single-storey pavilions due to loadbearing capacity and fire behaviour. Similar ideas can also be found in Germany:

a well-known example are the plastic ­sanitary modules in the athlete and later student hostel, built for the 1972 Summer Olympics at the Olympic Village in Munich. Timber room modules emerged in ­Central Europe by the early 1970s at the latest and, as a rule, were restricted to single-storey applications. In northern Germany, the Holtmann company, starting from an interest in prefabricated ­timber architecture, developed systems for timber-based room module con­ structions (Fig. 7). From 1972 onwards, numerous projects were realised, both for temporary as well as permanent uses. The construction projects ranged from school buildings to the addition of storeys in a hospital. The modules with standard dimensions of 3 ≈ 3 m, 3 ≈ 6 m, 3 ≈ 9 m

4 5 6 7 8

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 odel of pavilion made of load-bearing plastic M room modules, 1967, Ralf Schüler and Ursulina Witte Temporary building, Neuchâtel (CH) 1993, Bauart Architekten und Planer High-rise building comprising steel room ­modules for temporary housing, Tokyo (JP) 1972, Kisho Kurokawa & Associates Youth centre made of timber room modules, ­Hanover (DE) Schindler office building, Ebikon (CH) 1998, ­Kündig + Bickel Architekten a  Floor plan of standard floor, scale 1:500 b  Completed building Room module mounting, Schindler office building

Development

8 a

b

and 3 ≈ 12 m, as well as a square construction grid, are based on a glued-laminated timber skeleton structure, which is filled in with frame construction elements. Nail-plated trussed rafters covered the large ceiling spans in school buildings. Other companies experimented with foldable room modules, in order to reduce transport sizes. Ten years later, the demand for room module solutions stagnated; therefore, in 1985, the Holtmann company discontinued this line of business. The reasons for this may have lain in the generally weak construction growth of this period. The building boom of the 1960s and 1970s triggered by the baby boomers increasingly lost momentum. More­over, prefabricated construction in general had to grapple with a difficult image due to many faceless new buildings in the 1970s.

9

1990s / 2000s: Timber room modules for multi­ storey buildings

Multistorey construction using timber room modules was developed in the 1990s. The alterable or even temporary character of the buildings initially was the main focus. Switzerland and Vorarlberg played a pioneering role here. For lack of alternatives, architects first employed light timber constructions, such as skeleton structures or timber frame construction. The first permits for cross-laminated timber were not granted until 1998. This being the case, Sturm, Peter + Peter Architekten + Ingenieure, for ex­ ample, developed an extendable, cost-­ effective, two-storey single-family house using frame-constructed room modules in Munich from 1994 onwards. The very light and reduced building method was

possible thanks to the low sound insulation and fire safety requirements in singlefamily house construction. Multistorey office buildings in Switzerland The Swiss office Bauart Architekten und Planer, together with the module manufacturer Riedo AG, developed a system for temporary, up to four-storey-high office buildings in timber construction at the start of the 1990s. The highly flexible system Modular-T was based on a gluedlaminated timber skeleton and, due to the systematic omission of individual columns, allowed for various column-free spatial linkages. The Modular-T tempor­ ary building, completed in 1993, housed the site office during the construction of the Federal Statistical Office in Neuchâtel, as well as offices and workshops of the SBB railway company. It consists of an elevated base level for a loading zone, two full office floors, as well as a recessed top floor, and is composed of a total of 57 room modules (Fig. 5). Planned as a provisional arrangement, it was used for 15 years. The engineering office merz kley partner, specialising in timber structures, together with the timber construction company Erne from Laufenburg, Switzerland, ­experienced in room module construction since the 1970s, and with the Zurich architects Kündig + Bickel, also completed a three-storey office building – the administrative building for the research and development division of the lift manufacturer Schindler in Ebikon (Figs. 8 and 9). The building, completed in 1999, consists of a concrete base at ground level and three upper floors comprising a total of 66 room modules. During system development, the planners attached great importance to the flexibility of the building: the restructuring of the spaces, vertical extensibility, as well as 11

Development

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10

easy disassembly and reuse at a different location were basic conditions. All room modules were frame-constructed. It is interesting to note the combination of planar and spatial elements: the ceilings of the access corridor around the central atrium are part of the room modules. They protrude while also forming the supports for the closed ceiling panels, which are mounted as planar elem­ ents in between the modules in certain segments. In spite of a strict grid, the building evinces a wide range of pos­ sible room module applications. The ­spatial linkages appear generously proportioned, while the assembled room modules are, in part, open on both long sides. Development in Styria Hubert Rieß, an architect working in Graz, who was professor for design and building theory at the Bauhaus University in Weimar from 1994 to 2012, is considered a pioneer in the development of room module construction, combining craft-­oriented and process-driven thinking with an exploration of the typological and urban developmental possibilities. His projects and theoretical studies have focused on the complex, three-dimensional application of room modules and the differen­ tiated interplay of volumes and open spaces in new buildings as well as in the field of re-densification. For a location-independent study from 2002, he designed 64 ≈ 40 ≈ 15 m large “urban building blocks”. These multifunctional structures are surrounded by a shell of residential modules on their facades and roofs, which are accessed by lanes and squares. The cores accommodate public uses with less daylight requirement, such as theatres, cinemas, etc. The multi-functionality and the spatial complexity are also reflected in his largest completed room module project, the Impulszentrum in

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Development

10 A  xonometric drawing of a pair of modules, ­Impulszentrum Graz (AT) 2004, Hubert Rieß 11 Exterior view, Impulszentrum Graz 12 View of the courtyards, Impulszentrum Graz 13 Extension of Hotel Fetz am Bödele (AT) 1997, Leopold Kaufmann 14 Extension of Hotel Post, Bezau (AT) 1998, Oskar Leo Kaufmann and Johannes Kaufmann

Graz (Figs. 10 –13), completed in 2004. Remarkably, this is a research, laboratory and office building, even though Rieß’ theoretical focus had until then been on residential buildings. The project was conceived as a hybrid timber building: a three-storey, reinforced concrete building volume, set around a courtyard, houses the laboratory functions. In the courtyard, the office spaces are positioned as room module stacks. Every two individual volumes share a subordinated, transparently covered courtyard, towards which the office spaces are ­oriented. Two out of a total of 72 room modules respectively, measuring 3.90 ≈ 12 m, which are open on one long side, comprise one office unit. Two columns on the open side transfer the loads.

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Development in Vorarlberg In Vorarlberg, since the late 1990s, multistorey construction using room modules took its own developmental path, whose dynamics are based on the close informal collaboration between planners and the woodworking trade in particular. The circle of participating actors was limited in the early years: the architect Leopold Kaufmann, known as a pioneer in timber construction in Vorarlberg, extended the Hotel Fetz in the Bödele ski area in 1997 by adding two floors comprising a total of ten room modules, and thereby building the first timber room module construction in Vorarlberg (Fig. 13). These room modules were prefabricated as bare structures while the fit-out took place on site. Almost simultaneously, in

1998, two further hotel conversions were completed: the architects Oskar Leo Kaufmann and Johannes Kaufmann ­constructed an annex for the Hotel Krone in Au, consisting of 18 modules and a pitched roof, while adding two ­storeys as an initial extension of the Hotel Post in Bezau (Fig. 14). In both cases, and as is always sensible in timber room module construction, the close collaboration between architects, structural engineers and carpentry firms led to successful projects. These pioneering buildings were not yet based on the parallel development of cross-laminated ­timber. The extension of the Hotel Post consists of frame-constructed walls and glued-laminated timber ceilings. The ­factory-delivered degree of prefabrication,

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Development

15 15 H  otel with a timber room module structure, Garching (DE) 2015, Johannes Kaufmann ­Architektur 16 Overview of the chronological development of room module construction

right up to the interior furnishings of the rooms, was already very high in these projects. These early multistorey room module structures prove that the fast and efficient modular construction method has great potential, especially for hotel conversions in the Alpine region: a conversion with a longer downtime of hotel operations causes very high revenue losses; moreover, the frost-susceptible winter period is long and the risk of weather damages in existing buildings during the construction phase is accordingly high. Hence, interestingly enough, in Vorarlberg, multistorey construction using room modules began with the extension of existing buildings and the addition of floors. Further development subsequently took place primarily in the field of new buildings and in the ­following years, smaller projects were ­initially completed. In 1999, Johannes Kaufmann and Oskar Leo Kaufmann developed SUSI, an individual module for an approximately 50 m2 residential unit,

General development of room modules

which is still being created in many ­variations today. It was only about ten years later that another impetus in the development of the room module construction method was observed, initiated by the construction of the Alpenhotel Ammerwald near Reutte in 2009 (see p. 66ff.). Located close to Lake Plansee in Tyrol, the project was conceived by experts from Vorarlberg in an integral collaboration. The project has been widely publicised and has attracted a great deal of attention, since – besides its height with a total of five floors – the scale is new: 96 modules were mounted within ten days on the twostorey reinforced concrete base. The modules are made of cross-laminated timber, the predominant material in room module construction in Vorarlberg since its certification, constituting all the surfaces in the hotel rooms. The floor of the modules, too, consists of cross-laminated timber and dispenses with additional

Development of timber room modules Single-storey modules, Europe / USA

1890

First room module of reinforced concrete, France

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14

1900

Room module construction as an alternative to precast concrete slab buildings, USSR

1960

High-rise buildings of reinforced concrete room modules, US

1970

High-rise buildings of steel room modules, Japan From the 1970s onwards: single-storey room module structures

1980

Development

l­ayers or coverings, making it both the shell construction and the walkable surface at the same time. In the following years, a series of multistorey, high-volume projects were ­developed. Room m ­ odules produced in ­Vorarlberg were increasingly exported to Germany and Switzerland, as is demonstrated by the Hotel Soulmade in Garching near Munich by Johannes ­Kaufmann, which opened in 2016 and consists of 171 modules (Fig. 15). The cooperation between Vor­arlberg-based timber construction and structural engineering firms and German architects resulted in numerous projects, such as the European School in Frankfurt am Main (2015) by NKBAK, employing prefabricated room module staircases for the first time (see p. 102ff.); the refugee accommodation in Hanover, completed in 2016 and planned by MOSAIK architekten (see p. 94ff.); or the Woodie student hostel in Hamburg (2017) by Sauerbruch Hutton (see p. 80ff.).

Temporary structure in Neuchâtel (CH)

Addition of floor(s), Hotel Fetz (AT)

Addition of floor(s), Hotel Post (AT)

The current influx of refugees, alongside the already high demand for affordable housing in Vorarlberg itself, has also ­become an engine for room module ­constructions. The architect Johannes Kaufmann has already developed an ­entire range of systems for flats of various standards. A trendsetting realisation is the “Wohnen 500” complex in Mäder (see p. 92f.), completed in 2016. This ­project combines cost-efficient construction with high ecological and aesthetic demands. The goal is to repeatedly implement the building concept; two further complexes in Feldkirch in Vorarlberg and in Höchst near Frankfurt have already been completed. 2018: Status quo

uncommon anymore. This construction method has also been developing in height: in the Puukuokka residential building in Finland (2015) by OOPEAA, seven to eight floors are stacked utilising only modular construction (see p. 86ff.); the Hotel Jakarta in Amsterdam (2018) by SeARCH even has nine floors consisting of timber room modules. By employing a composite construction comprising a primary timber skeleton and room ­modules inserted on a base level made of reinforced concrete, the Treet in Bergen reaches fourteen floors (see p. 77ff., 2015). The constructive collaboration between committed architects, specialist planners and innovative timber construction firms has led to a series of outstanding architectural projects.

Timber room module construction has proven itself as an approach of its own for multifamily housing, hostels, hotels, schools and office buildings, and con­ tinues to break new ground: projects of the order of 200 to 300 modules are not

Notes: [1] Wachsmann, Konrad: Holzhausbau. Technik und Gestaltung. Berlin 1930 [2] Wachsmann, Konrad: Wendepunkte im Bauen. Wiesbaden 1959 [3]  Das Werk. Architektur und Kunst 04/1966, p. 132

Office building in Ebikon (CH)

1990

From the 1990s onwards: multistorey room module structures

Impulszentrum Graz (AT)

2000

Hotel Ammerwald (AT)

Residential complex in Jyväskylä (FI)

2010

Residential tower in Bergen (NO)

Student hostel in Hamburg (DE)

2020

From the 2010s onwards: room module structures at / above the high-rise limit

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Design and Typology

Designing with room modules

Load-transferring room modules

Self-supporting, inserted room modules

Combination: secondary load-bearing room modules inserted in primary structure

The process of prefabrication shapes design in room module construction more strongly than in any other building method. The decision to use room modules must already be taken at the start of the design phase, since the spatial structure always follows the logic of the module. The strong spatial guidelines predefined by this building method characterise the entire design process. While the design of floor plans with closed cu­bicles (such as hotel rooms, flats) can be readily structured, designing with open room modules (such as multiplemodule flats) is relatively complex, since the spatial-functional requirements have to be correlated with the modules’ boundaries. Here, the diversity of possible solutions is limitless. Support structure hierarchy and space creation – load-bearing and inserted room modules

Also for reasons of transportability, room modules are usually sufficiently sturdy to transfer their own weight. However, modules are not always conceived to be able to receive and transfer the loads of other stacked modules across several floors. Hence, one distinguishes between the two basic types of the loadbearing and the inserted room module (Fig. 1).

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2D supports 3D: inserted room modules in a planar building structure

3D supports 2D: room modules with mounted ceiling slabs  ypology of hierarchy of load-bearing structure T Sanitary room modules in planar, prefabricated timber construction, Residential building – construction in a parking area, Munich (DE) 2016, ­Florian Nagler Architekten a  Floor plan, scale 1:200 b  Delivery of the sanitary room modules

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 ift shaft of cross-laminated timber as prefabri­ L cated, inserted room module, Kampa adminis­ tration building, Aalen-Waldhausen (DE) 2014, Florian Nagler Architekten and Kampa GmbH Combination of load-bearing timber frame and ­inserted room modules, Treet residential tower Bergen (NO) 2015, ARTEC

The most common case of an inserted module is the sanitary module, which is placed on the raw ceiling of prefabricated timber buildings or solid structures (Fig. 2). In doing so, the constructional strategy consists of entirely prefabricating the room modules for the extensively equipped areas and realising the corres­ pondingly simpler elements in a planar form. The constructional challenge lies in the formation of low installation heights, in order to ensure an as threshold-free

Design and Typology

2 a

b

3

transition as possible from the cubicle to the space and on the floor level, as well as to maximise clearance heights. Typical applications are bathrooms in hostels, flats, hospitals and hotels. The application of inserted room modules in open skeleton structures is also conceivable, for example to organise the necessary auxiliary functions in openplan offices according to the room-inroom principle. These inserted modules are much more frequently manufactured from lightweight steel profiles and dry construction boards rather than timber or using very thin re­­ inforced concrete walls. Another variant of the inserted room module are lift shafts, which are conceived to be independent of the rest of the load-bearing structure of the building for the purpose of sound insulationrelated decoupling and, thanks to threedimensional prefabrication, are delivered to the construction site complete with fire safety cladding and preinstalled rail technology (Fig. 3). An interesting construction method was applied in the high-rise project in Bergen completed in 2015: a shelf-like, primary timber frame absorbs the vertical and horizontal loads of the 14 modular floors (Fig. 4 and p. 77ff.). Every fifth floor has been designed as a special floor with a load-bearing platform, on which four floors of room modules are stacked. A potential further development of this idea would be a combination of filled and vacant “shelf areas”, to use further spatial possibilities of this constructional principle, and for example, to realise open, intermediate floors, multistorey halls, stepped floors, etc.

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Design and Typology

5 6 7 8 Two joined, open modules, such as for an office space

Module for a complete flat

9

Module includes wet cell

Several joined modules, such as for a classroom

Module = Room 5

 ypology of the relationship between space T and module Group office comprising two joined room ­modules, Impulszentrum Graz (AT) 2004, Hubert Rieß Classroom comprising three joined room ­modules, European School, Frankfurt am Main (DE) 2015, NKBAK Flats comprising room modules, Johannes ­Kaufmann Architektur a A flat comprising two room modules, “Wohnen 400” b A flat comprising three room modules, “Wohnen 500” Room module as special type, stackable minimal housing, Ofis Arhitekti a  Combination possibilities b  Use as public library, Ljubljana (SI) 2017

In a great many room module buildings, the room modules also transfer the loads from planar elements. This is often the case in central corridortype access areas. However, the constructional principle is not necessarily ­limited to this application; a multitude of combinations comprising planar and three-dimensional elements is conceivable. These considerations could conceivably lead to new types of modular structures. In the Schindler office building in Ebikon, this principle has been implemented in the spacious central zones in an exemplary manner (see Fig. 8 a, p. 11). Relationship between space and module

The original type of room module is the direct formation of a – usually repet­ itive – space in a module. In a first ­extension, a bathroom unit is incorporated in the module. This already describes the most commonly used type of room module, which – in slightly ­different variants – is employed in ­hotels, residential and nursing homes or hospitals.

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b

Today, however, room modules are being used in considerably more diverse ways. For example, entire flats can be accommodated in large, front-to-back room modules. In this case, the utilisation unit corresponds to the module boundary – a highly effective typology for reasons of sound insulation and fire safety (see “Layer structure”, p. 36ff.). Several joined modules make up larger flats. This allows for an almost limitless variety of flat types (Fig. 5). The modules are often divided perpendicularly to the facade, like in cross-wall housing construction (Fig. 8; see also the “Wohnen 500” residential complex in Mäder, p. 92f.).

Design and Typology

In the Puukuokka residential complex in Jyväskylä, Finland, on the other hand, and in reversal of this principle, the flats consist of two room modules lying in ­parallel to the facade. The internal, ancillary module houses all installations, which can be serviced from the central aisle, while the external one accommodates the habitable spaces (see p. 86ff.). In case parts of flats extending over two modules are linked only by door openings or passages, these can usually be prefabricated including the floor construction, while only the frames of the openings are closed on site.

a

In office buildings as well as in schools and day-care centres, the strategy of composing large spaces such as classrooms or group offices out of several modules has established itself (Figs. 6 and 7). In this case, it is necessary to implement the floor construction later so that the joints between the modules are not visible in the floor covering. Apart from the purely orthogonal stacking of cubes, special and free-form types of room modules are also possible. In terms of their construction and production, such types strongly differ from the rather systematised standard solutions. They require highly individual production planning and thus represent more of an exception. In this context, it is also worth mentioning the vertically and horizontally stackable minimal dwellings of the Sloven­ ian firm Ofis Arhitekti (Fig. 9). Access typology

In room module construction, access is also of vital importance, as it significantly shapes the quality and form of a building: with a suitable access system, even a very stringently structured modular building can develop spatial complexity and quality.

9 b

19

Design and Typology

Linear typologies Providing linear access to a string of room modules is especially suited for building types with many small utilisation units (Fig. 10). This equally applies to blocks of flats, hotels, and residential and care homes, which primarily only differ from each other due to varying requirements for ancillary spaces and common areas. The basic typologies are the central corridor and the arcade. However, the possibilities are in no way limited to these relatively rigid stereotypes. By enlarging, opening, ­shifting and fanning out, as well as switching between external and internal access, spatially interesting floor-plan ­layouts are created, which can be readily realised using room modules (see European School in Frankfurt am Main, p. 102ff.). A significant advantage of linear access lies in the possibility of being able to provide ring-like emergency escape and rescue routes. In this case, two independent escape directions are guaranteed. In higher building classes, in particular, and in the fire protection concept, this can be an important argument in favour of timber construction.

Central-corridor typology

Arcade typology

Point-based typologies Purely point-based access is less common in room module construction and offers less variation since only a limited number of units can be connected at the access points (Fig. 11). In combination with linear access elements, many variants can be created, for example by widening the stairwell into an interior atrium. The compact core-access building becomes interesting especially when combining utilisation units comprising several room modules (see the “Wohnen 500” residential complex in Mäder, p. 92f.), since the ratio of access area to useable area is highly efficient here and the design-related variability is substantially broadened.

Combinations of room modules and planar elements in housing ­construction An intelligent combination of room modules and planar elements, a hitherto less explored field in timber construction, merges the advantages of both ­construction methods: while room mod-

ules especially lend themselves to complex, extensively equipped areas, planar elements readily allow for open spatial configurations and wide-span constructions. The high sound insulation level of double-shell room module construction can be optimally used in such combin­ ations if the modules are explicitly located at the divisions of the utilisation units. These considerations, applied to multistorey housing, for example, result in two basic types that differ from each other in space creation and construction (Fig. 13). Auxiliary room modules

Bathrooms, kitchens and stairwells are conceived as free-standing room modules. They serve as supports for the ceilings of ideally flexibly useable areas of a flat. Alternatively, the room modules could also be employed in the form of inserted elements. This is especially suitable for uses where larger ceiling heights are available than is normally the case in housing construction. Layered models

In this model, several adjacent room modules form levels in a flat, which

Two emergency escape directions

Variations of linear access 10

20

11

Design and Typology

12

­ lternate with layers of planar elem­ a ents. This approach can be applied in various variants (Fig. 12). The most ­consistent appear to be typologies where the modules enclose a middle zone of planar elements on both sides, since in this case, the doubling of the construction simultaneously ­creates the separation of the utilisation units. Possible applications for these include relatively large flats, starting from four rooms (Fig. 14 a) and new ideas of floor plan organisation such as for communal living. This typically takes the form of a flat share where several separate, individual areas including bathrooms and possibly small kitchens are combined with spacious common areas for communal cooking, dining and living. Such so-called cluster flats respond to an ever greater number of singles in the population development as well as the housing scarcity in large cities by introducing an additional stage between privacy and public life. It seems reason­ able to examine these forms of housing with respect to their suitability for layered models (Fig. 14 b).

Basic types and variations of linear access Variations of point-based access Basic variants of layered models Combinations of 2D and 3D prefabrication a  Room modules as serving cores b  Layered models 14 Floor plan studies, scale 1:500, design René Schröttle a  Room modules as serving cores b  Layered models

13 a

b

10 11 12 13

14 a

b

21

Design and Typology

b

c 15 a

Combinations of spatial and planar modules in hotel construction Hotel buildings or similar construction tasks, such as residential homes or ­hospitals, are characterised by recurring sequences of rooms with anterooms and sanitary areas. In combinations ­comprising room modules and planar ­elements, the sanitary areas are always prefabricated, while on the other hand, planar elements are used for the habitable spaces. A module which is inserted into a space is always free from requirements concerning sound insulation and fire safety (Fig. 15 a). If the room module independ­ ently stands in front of the planar elem­ ents, thus forming the separation of the utilisation unit, these requirements must be met (Fig. 15 b). The strategy of organising two sanitary units in one room module improves transport efficiency, expedites assembly, reduces the number of joints, and reinforces the structure under horizontal load application (Fig. 15 c). Particular constructional care must, in this case, be taken for the transition between the room module and the planar element, in order

16

22

17

to fulfil the sound insulation requirements between the utilisation units.

Room modules for building stock extensions The demand for re-densification remains consistently high in cities. In building stock extensions, especially in the case of measures that are to be carried out during ongoing operations, the advantages of prefabrication increase vis-à-vis new buildings. This mainly applies to the low-emission and extremely fast assembly on site in particular. It is not surprising that the first multistorey room module buildings, as in Vorarlberg for example, were realised as additions of storeys to existing hotel buildings (see “Development in Vorarlberg”, p. 13ff.). In principle, cubicles are conceivable for horizontal as well as vertical building stock extensions. In the case of horizontal extensions in particular, which usually intervene in the spatial structure of existing units, the combination with a new, ­timber-constructed building shell is useful in order to energetically and technic­

Design and Typology

18

ally raise the entire building to the standard of a new build (Fig. 16).

in the added parts. In case this is not possible, loads can be diverted and ­conduits directed to the correct pos­ ition by introducing an additional layer between the existing building stock and the additional storeys, for example by means of a tier of timber or steel profile beams. Depending on the project, the high rigidity of the modules can also serve to bridge relatively large spans in the existing building stock.

The clearly structured and geometrically simple residential buildings of the 1950s in particular have great potential for ­horizontal extensions. The often very small building depths and relatively spacious distances between the buildings make possible an additional layer of space (Figs. 17 and 18) in many cases. A hindrance may, however, be the partly very low clearance heights combined with very slender ceiling constructions, so that an extension is sometimes incompatible with building regulation specifications and therefore not possible.

Public perception and strategies Public perception of rationally shaped construction using room modules seems surprisingly emotional and ambivalent. Firstly, very high expectations are placed on the construction method: the object­ ive is to create urgently needed, afford­ able housing space, to at last realise the dream of completely digitised and automated construction as in the auto­ mobile industry, and to find the equivalent of today’s flexible lifestyle in similarly flexible buildings.

While it is the spatial interrelationship with the existing building stock that is formative in the case of horizontal extensions, the addition of storeys can be designed much more independently of the spatial concept (Fig. 19). The load-bearing structure, circulation and building services routes of the existing building stock, in conjunction with the spatial requirements for the addition of storeys, form the basic parameters for planning. Ideally, there exists the possibility of continuing them

19 a

Secondly, this construction method faces strong prejudices. Exaggerated some-

b

15 C  ombinations of room modules and planar ­elements in hostel and hotel construction a  Inserted room modules b  Self-contained room modules c  Two bathrooms in one room module 16 Exemplary floor plan study, typical 1950s floor plan with horizontal extension using room ­ module construction (grey = new additions), scale 1:500 17 Typical housing development of the 1950s with small building depths and large intermediate spaces 18 Possibilities for the extension of building stocks using room modules 19 Addition of floors using room modules, ­Residential building, Geneva (CH) 2017, ­Kunz-Architectes a  Room modules open to the southern side b  Closed rear side

23

Design and Typology

what, there is an apprehension about an anonymising effect in residential districts. This uneasiness is certainly rooted in the period of prefabricated concrete slab construction in the former Eastern bloc countries, from circa 1955 onwards, but also in the monotonous large housing estates in city suburbs in Western countries, with hardly any social or cultural infrastructure. Planners and manufacturers to this day feel that their credentials and existence are jeopardised by large companies, offering quick, inexpensive and stand­ ardised alternatives to individually planned buildings. City planners and architects fear a loss of building culture due to a lack of individuality and a negation of the genius loci, the specific character inherent in every place that also necessitates a specific constructional response. An objective assessment of the potential and possible strategies of room module construction may be useful in light of these reservations. There are various conceptions of room module construction, which need to be viewed in a differentiated manner. In this context, one must distinguish between two fundamentally different development strategies, which are described below. Adaptable room module construction systems

One development strategy is adaptable room module construction. This variant is based on the following scenario, which differs from the range offered by conventional room module manufacturers due to the quality standard, system variability and the timber construction: only newly built, standardised buildings with a clearly defined catalogue of options, similar to the configuration of features in a car, are offered, for example by gen24

eral contractors. In keeping with individual serial production, a wide range of choices within a system is technically possible. As the number of units rises, variability also increases. Well thought-out floor plans and highly adaptable facades with excellent design quality form the basis.

planning and production possibilities as well as property sector-related conditions are subject to constant change. Construction systems with appropriate flexibility would be necessary to be able to respond to all these transformations. Individually developed room module architecture

The potential lies in a substantial reduction in building costs and project dur­ ations while maintaining high ecological, aesthetic and technical implementation quality, since planning efforts can thereby be significantly reduced. Sensible application of parametric planning methods would be a given in this case. At appropriate volumes, much more extensive automation of production than hitherto applied would seem practical and be economically feasible. The role of the architect would be limited to the adaptation of the system to the conditions of the plot and customer requirements, while the possibility of responding to special features in the surroundings would be restricted. The task of city planners would lie in designating suitable plots for this procedure and developing urban planning-related guidelines which can be implemented in room module construction. It is remarkable that such construction systems have so far hardly established themselves in timber construction despite their obvious potential, having remained at the prototype stage and in small-scale production. The commercial structure of the timber construction industry with its small number of large companies surely is an important reason for this. Alongside the required extent of demand, the continuously changing and regionally differing parameters constitute another obstacle: legal and normative regulations, requirements specifications of users,

The variant comprising individually developed room module architecture much more closely corresponds to the building practice in Central Europe. Here, the architects’ design effort results in the ­individual use of the advantages of room module construction. For a specific building task, room module construction is defined as being the best solution, leading to the design of a corresponding building. In doing so, the involved planners determine the overall floor plans, facades, and module sizes in a projectspecific manner, resulting in buildings that individually respond to the surrounding conditions and boast high architectural quality (Fig. 20). In constructional terms, various preferred variants have developed at timber construction companies, which are applied on a project-wise basis. Hence, one ­cannot speak of a construction system but rather of a construction method. In this case, planners’ and manufacturers’ efforts are equally required. Architects continue to provide the design expertise for the overall project. The planning of base levels, stairwells and auxiliary buildings still requires the customary detailing. Moreover, module fittings must be correspondingly specified. Here too, the load-bearing structure and building services are developed by specialist planners. Only the detailed planning of the modules themselves is, appropriately, carried out by the timber construction company. Apart from pure timber construction with a partly comparatively high

Design and Typology

level of automation, the finishing trades are, as a rule, performed more effectively by medium-sized firms in a relatively conventional, albeit serially-produced manner. Conclusion

In summary, both exaggerated expec­ tations and apprehensions must be put into perspective. Room module con­ struction alone does not automatically lead to a reduction in building costs. However, thanks to its efficacy, it offers an excellent expenditure-quality ratio. Moreover, it is a construction method

that is well-suited for future automation steps without being a threat to the existing planning and manufacturing culture. Room module construction offers a high degree of flexibility, which is however currently underused. The built examples documented in the project section prove that room module construction with a high architectural quality is possible.

20 S  tudent hostel, Hamburg (DE) 2017, Sauerbruch Hutton

20

25

Constructing with Timber

1 a

b

What does a module consist of?

As a rule, room modules are cuboids, with rectangular floor plans and six boundary surfaces, of which two each have the same size. In constructional terms, one distinguishes between longitudinal walls, transverse walls, the ceiling / roof, and the floor. From a constructional as well as a production-related and logistic perspective, all six sides are ideally closed. However, this is only the case when one utilisation unit coincides with the dimensions of one room module, as in applications such as hotel rooms, small flats or student residence complexes. Individual surfaces of the six sides of a cuboid can, of course, be removed depending on the design, permitting ­generous spatial links, combinations of several modules to form one space, or large window surfaces (Figs. 2 and 3). 1

2 3

4 5

26

 eiling constructions in opened room modules C a Transverse-span ceiling, load-bearing longitu­ dinal walls b Longitudinal-span ceiling, load-bearing transverse walls, alternatively transverse-span beams and column c Longitudinal-span joists and transverse-span ceiling elements, load-bearing transverse walls, alternatively columns Example of a central module for a group room in a nursery with provisional reinforcement for transport Degrees of opening in room modules a Closed room module with door and window opening in the transverse walls. Application in a residential home room, for example b Single-side open room module, self-supporting. Application as an edge module for a classroom, for example c Two-side open room module, which must be temporarily reinforced on one side for transport and mounting. Application as a central module for a classroom, for example d Three-side open room module, which must be temporarily reinforced on two sides for transport and mounting. Application as an open-plan ­office, for example e Room module with openings in the floor and ceiling. Application as stairwell, for example The floor and the ceiling are positioned between the longitudinal walls. Mounting of modules for an open-plan office. Temporary reinforcement in two directions is ­provided by three-layer slabs. 2

c

However, after omitting more than one ­lateral surface, the cuboid becomes stat­ ically unstable. At least for transportation purposes, the cubicle must in any case be temporarily reinforced and provisionally closed, to prevent weather effects on the interior construction. The number of open sides on the room module usually also determines the span direction of the floor and ceiling. Normally, i.e. in the case of closed modules, the vertical load transfer takes place via the longitudinal walls (Fig. 1 a). The ­primary reason for this is the shorter span. Moreover, the transverse walls are at least partially open due to doors, windows and installation conduits, if they are oriented towards the corridor and facade, as is usually the case. The ceiling and floor respectively support independent and, moreover, different

Constructing with Timber

3 a

b

c

d

e

loads: the floor supports the live load and the floor construction, while the ceiling supports only itself. The top module, depending on the construction, additionally carries the loads from the roof. In cases where modules with one or more open sides lack at least one longitudinal wall, the rule above does not apply and the vertical load transfer must be solved differently. In doing so, two options are available: the first consists of transferring the loads via the transverse walls, and spanning the ceiling or the floor longitudinally to the module (Fig. 1 b); the second involves the use of joists instead of the missing walls (Fig. 9, p. 30). Load transfer from the joists takes place in a pointbased manner via columns at the module corners. In this case, the ceiling again spans transversely to the module and the above-lying, transversely spanning floor also rests on the joist of the lower module (Fig. 1 c).

4

In rare cases, especially in stairwells, room modules lack a floor and a ceiling (Fig. 10, p. 30). Here too, stability during transportation and assembly must be ensured by temporary measures (Fig. 5) or an appropriate design of the staircase structure. What timber construction methods are used?

Frame construction, board stacks, crosslaminated timber, hybrid constructions: in general, the entire range of systems and system combinations commonly used in timber construction today is available for use in room module construction (Fig. 6, p. 28). There are no universally valid rules as to when which system is to be applied. The decision is highly dependent on the basic conditions of a specific project. The following section provides a decision

5

27

Constructing with Timber

Columns / Beams

Vertical construction elements

Horizontal construction elements

6

28

Board stack

Frame construction

Cross-laminated ­timber

Constructing with Timber

6

7

aid on the basis of decisive criteria. Wood-concrete composite systems are also conceivable though they are not very common due to their usually small spans and weight. When using concrete, thin reinforced concrete prefabricated parts rather than floor elements are normally employed. In doing so, the focus is on sound insulation and economic efficiency considerations. The following criteria are determinative for selecting the construction system of the floor and ceiling (see also Fig. 7): • Statics: For shorter spans, solid timber constructions such as cross-laminated

timber or board stack elements take centre stage. Board stack elements have disadvantages with respect to the design of reinforcement panels. They must either be constructed as glued elements or be additionally reinforced using appropriately linked composite wood panels. At larger spans, more dispersed systems are employed, such as joists, skeleton structures consisting of main and secondary girders, as well as box beam elements. • Formal requirements for the surface: In cases where wooden surfaces are desired, primarily three-layer panels or cross-laminated timber are suitable

Columns / Beams

Board stack

 ossible combinations of vertical and horizontal P elements in room module construction (sche­ matic drawing). Moreover, various elements for the floor and ceiling are conceivable, while external and internal walls must also be considered in a differentiated manner. Comparison of advantages of vertical and horizontal elements in room module construction (+  limited suitability, ++  suitable, +++  highly suitable)

for the ceiling due to smaller loads and depending on the span. • Building physics-related requirements: Especially for floor components which are in contact with the outdoor air, thermal requirements speak in favour of using insulated timber frame elements. The sound insulation requirements, on the other hand, do not have a decisive effect on the choice of system, since their fulfilment is mainly ensured by the floor construction and decoupling of modules. The insulation on the roof elem­ ents is also not determinative for the selection of the roof element, since it is often only applied on the building site.

Frame construction

Cross-laminated timber

+

+++

+

+++

Vertical construction elements

Large vertical loads

+++

+++

Large horizontal loads in the plane of the panel Wall-like supports Exposed timber surface Encasement required

+

+++

++

+++

+

+++

+

+

+++

+

+++

+

++

+

++

+++

+

+++

+

+++

+

+++

++

++

Horizontal construction elements

Large span Exposed timber surface Encasement required 7

Room height

+

29

Constructing with Timber

• Fire safety: In case of fire exposure, the load-bearing structure of the floor elements is, as a rule, protected from above by the floor construction and from below by the ceiling of the module lying underneath. For this reason, fire safety here doesn’t influence the choice of system. The situation is different in the case of ceilings. They are directly exposed to fire. If encased timber is required, it does not matter whether the encasement is followed by a ceiling comprising linear or planar building components behind. Without encasement, panel-type components normally take centre stage, which make a direct contribution to fire resistance and smoke-proofing of horizontal module divisions.

8

•C  eiling height: The height of modules is restricted due to transportation on traffic routes, especially due to the clearance height under bridges. An external height of approx. 3.20 m and above requires special vehicles for transportation (see “Process”, p. 50ff.). The reduction of building component superstructures to ensure maximum interior dimensions or required min­ imum ceiling heights often is a key criterion. This, in turn, influences the choice of system for the floor and the ceiling.

9

• Implementing firm: The preferences of the implementing firm, and here especially including the aspect of ­vertical integration, i.e. whether module production has component production attached or whether ­components have to be additionally purchased, play an important role in the selection of the construction system. The criteria for selecting the construction system of the walls are:

10

30

Constructing with Timber

 8 E  xample of a module with longitudinally loadbearing ceiling and floor elements made of ­hollow box girders. The elements rest on the load-bearing external walls or a ceiling-identical transverse beam and columns in the centre of the element.   9 Shell structure of a module, European School, Frankfurt am Main (DE) 2015, NKBAK. The joists rest on columns at the facade and, on the other side, on the corridor wall. The ceiling elements and the floor elements likewise span in a transverse direction. The thin floor element is fixed with four temporary tension rods. 10 Stairwell module of the European School

• Statics: For highly loaded walls, solid systems are useful, especially when the load-bearing walls do not have larger openings and the loads can be evenly distributed. In this way, very thin wall structures can be achieved. Moreover, cross-laminated timber panels are slabs per se and can therefore accept high stiffening loads or be designed as wall-type supports. • Formal requirements for surfaces: In cases where timber surfaces are desired, cross-laminated timber or board stack elements take centre stage. These products are offered in qualities that allow them to be directly used as finished surfaces. Timber frame elements with wooden panelling that is suitable as a finished surface are complicated to manufacture. • Building physics-related requirements: Walls that are part of the building shell are often built as timber frames due to the required thermal insulation. Moreover, sound insulation requirements between modules influence the choice of wall structure. Timber frame elements with several thin panels display better sound insulation-related behaviour than solid panels. • Fire safety: With respect to fire safety, the question of encasement is also of crucial importance. A requirement for encasement tends to speak in favour of building the walls as timber frames. Exposed timber surfaces are, as a rule, designed as solid timber constructions. In the case of such load-bearing timber walls, the proof for the fire rating requirement is produced by a burn-up assessment: in the event of fire, and ­following the underlying period of time, the remaining wall cross-section must

11 Load influences on an individual room module a Vertical surface loads comprising net weight and live load b  Horizontal surface loads due to wind c Individual loads, due to e.g. load transfer from adjacent modules 12 Basic static loads and support reactions a Loads on panel, due to e.g. wind or live loads b  Compressive loading c Slab loading, due to e.g. pointwise s­ upports and /or cantilever d Slab loading, due to e.g. transfer of wind and earthquake loads

be able to guarantee the load-bearing capacity of the building. a

• Implementing firm: The proposition ­formulated for the selection criteria regarding floors and ceilings applies here in the same way Load transfer and proofs for individual modules

The following forces act on every module, independent of its position or arrangement (Fig. 11): • live load as vertical surface load acting on the floor • dead load of floor and ceiling as vertical surface load • dead load of the walls as vertical line load  • horizontal equivalent loads due to earthquakes The following forces additionally act on edge modules: • wind load as horizontal surface load In cases where several modules are stacked on top of or next to each other, they – as a rule – form a cluster: in addition to the loads described above, and depending on the arrangement of the modules and the position of a given module within the cluster, point or line loads will act on every module on account of load transfer from the upper modules to the foundations. The above-mentioned forces result in panel and slab stresses on the individual components (Figs. 11 and 12). This, in turn, leads to bending moments, normal forces as well as shear forces acting on the floor, ceiling and walls. It is necessary to first conceptually determine the transfer of these stress resultants from the top module to the foundation. This means that the manner of interoperation of the modules is first defined. Subsequently,

b

c

b

11

a

b

c

12 d

31

Constructing with Timber

timber profiles decreases in a discontinuous fashion as the fire duration increases, owing to the crosswise structure.

Most modular structures have a fire resistance requirement of at least 30 minutes. If this requirement is not met by cladding or encasement, the proofs must additionally be provided in terms of a burn-up assessment, i.e. for the load case of fire, with reduced cross-section. In cross-­ laminated timber components, particular attention must be paid to the layered construction and the layer thicknesses. The load-bearing capacity of cross-laminated

In multistorey arrangements, and depending on the choice of timber construction system, care must be taken to avoid an add-up of lying timber, i.e. timber which is inconveniently loaded transversely to its grain (Fig. 13 and Fig. 4, p. 27). The doubling of components, in particular, very rapidly leads to a large height of lying timber, especially in conventional timber frame construction (platform-type construction), which can result

in problems due to positioning variations at transitions to differently constructed components (such as elevator shafts and concrete cores). Bearing of modules

Modules can be positioned directly at floor level or on a solid building plinth. In both cases, the preferred bearing condition for modules is a line support underneath the load-bearing walls (Fig. 15). Point-based supports on columns or ­individual foundations are also possible. In this case, however, the module walls must be designed as wall-like supports

x

x

the stress resultants are calculated and the proofs for the relevant components and connections are provided.

13 a

32

b

13 In multistorey modular buildings, the deformation and shrinkage behaviour of horizontal timber must be taken into account a Multiple layers of timber are transversely loaded, resulting in settling due to compression and shrinkage of the transverse-lying timber due to drying after installation. b If consistent transfer of loads in timber loaded in parallel to its grain is taken into account, settling is minimal. 14 Twelve modules in various arrangements: force F1 in arrangement a is four times as large as force F2 in arrangement b. 15 Classification of supports for module floors on a solid base level

F1

F1

Anordnung A A 14 a Anordnung

and the load concentrations in the walls (compressions and standard force) accordingly considered. For ground-based positions, the support can be a base plate or a strip foundation. When dispensing with a base plate made of concrete, the floor of the lowest module forms a part of the building shell and must be accordingly designed with respect to building physics and statics. In many cases, modules stand on one or more base levels. These are frequently made of concrete, since they feature spaces whose size does not correspond

a  Substructure with point support

d  Line support with beams

Wind

Wind

Wind

Wind

Constructing with Timber

F2

F2

Anordnung Anordnung B B b

to the grid dimensions of the modules on account of their use. The most common example are hotels with open zones on the ground floor, such as a lobby, restaur­ ants or conference halls and the modular rooms on the upper floors. Therefore, load transfer often takes place in the ­ceiling above the ground floor or in one of the upper floors, i.e. the ceiling is ­designed as an underpinned ceiling. The ­underpinned construction must especially have high rigidity in addition to its loadbearing capacity, so that undesired load concentrations in the lowermost modules are avoided.

Reinforcement of multistorey room module ­constructions

When modules are stacked, the hori­ zontal loads described above, such as wind loads, must also be considered besides the vertical loads.. These loads must be safely transferred into the foundations. For this purpose, various concepts can be applied (Fig. 16, p. 34): ­usually, the modules are coupled to each other and act in a cluster. Depending on their arrangement, this results in highly varied loads in the individual modules, according to their position within the cluster (Fig. 14). Especially along the

b  Module walls act as wall-like supports

c Arrangement b leads to load concentrations in the support points

e  Line support with underpinned ceiling

f Sufficient rigidity of the line supports is ­important in order to avoid load peaks in the support points.

15

33

Constructing with Timber

a

b

c

narrow sides of the modules, which as a rule have large openings, this quickly leads to elaborate and different con­ structions, depending on the loading ­condition. This contradicts the principle of endeavouring to implement as many identical modules as possible. For this reason, attempts are often made to reinforce the modules using additional external ­elements, such as bracing (Fig. 16 b), or components which are independent of the modules, such as stairwells, elevator shafts, etc. In the transverse direction of the modules, this is primarily accomplished by a connection to the above-mentioned, module-independent components (Fig. 16 c, d and e). In the longitudinal direction of the modules, reinforcement via the usually large number of walls is not a problem. Arranging rigid joints at the corners of modules, as applied in steel construction and occasionally also in timber construction, should be avoided, as rigid joints in timber construction are highly complex and less efficient, especially with respect to stiffness.

d

e

16

34

Linking modules

For reinforcement purposes, modules must be connected to each other and the adjoining, reinforcing components. Almost always, the boundary surfaces of the ­modules are either a part of a ceiling or a dividing wall between different util­ isation units. Due to the characteristics of the system, a doubling of surfaces occurs at these points, as already mentioned. What – from a constructional point of view – represents an additional expense, and hence a disadvantage, is an advantage from a building physicsrelated perspective, more precisely with respect to decoupling for sound insulation purposes. Too many connections, however, nullify this advantage.

Constructing with Timber

17 a

b

The objective should therefore be to decouple connections, if possible with suitable intermediate layers made of ­elastic materials (Fig. 20). Moreover, it is also possible to ensure shear force transfer using geometric form fits (cams, recesses, notches) or through friction (Figs. 17–19). Crucial issues for detail development are: • Transfer of vertical and horizontal loads and, if applicable, safeguarding against raising • Optimisation of sound insulationrelated decoupling of supports 18 • Simplification of exact positioning of room modules in the assembly ­process • Optimisation of weather-protected assembly, even during precipitation

16 P  rinciple possibilities of reinforcing room module buildings; in longitudinal direction, reinforcing by means of the numerous walls is, as a rule, not a problem. a Modules are reinforced in both directions by means of the module walls. b Modules are reinforced using an additional ­construction, such as tensile cross-braces in this case. c Modules are compressively sandwiched in the longitudinal direction of the building (transverse direction of the modules) between 19 two cores. In a transverse direction and ­depending on the arrangement, buildings can be reinforced by the large number of ­longitudinal module walls up to the high-rise building limit. d Modules are attached to a core in both ­directions. e Modules are attached to the central core in the longitudinal direction of the building in a tight tensile and compressive connection (for reinforcing in transverse direction of the modules, see a). 17 Module connections a by means of cams and recesses for positioning and shear force transfer b by means of conical rods (only for positioning) 18 Cams for the transfer of reinforcing loads in the lower module 19 Recesses for form-fitted connection in the upper module 20 Form-fitted connection, decoupling with elas­ tomer strips 20

35

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Case Case 22

Case Case 11 UU UU 11

UU UU 22

UU UU 11

UU UU 22

1

Layer structure This chapter discusses the constructions of dividing walls, ceilings and floors, which constitute the major interior components of a room module. The structure of these components is determined by aspects concerning surface design, manufacture and the load-bearing structure, as well as by sound insulation and fire safety requirements in particular. The doubling of walls and ceilings or floors, due to systemic room module characteristics, largely corresponds to the sound insulation requirements in timber construction. This especially applies in cases where the module divi­ sion coincides with the boundary of the utilisation unit (Fig. 1, case 1). If the utilisation units are larger than the modules, doublings due to system characteristics occur, partly without a sound insulationrelated need (Fig. 1, case 2). Sound insulation

1 2 3

36

 elationship between the room module and R the utilisation unit (UU) Requirements regarding airborne sound and ­impact sound Fire stress of (a) wall structures and (b) ceiling structures

In timber construction, due to the low bulk density of the material, multilayered constructions are necessary for meeting high sound insulation requirements. In cases where one module corresponds to one utilisation unit, the doubled construction is applied to precisely those components that are already expected to meet higher sound insulation and fire safety requirements. This circumstance makes room modules made of timber more efficient in constructional terms compared with those of reinforced concrete. The dimensions of wall and ceiling thicknesses of timber room modules are comparable to those of superstructures of conventional timber constructions. Thus, a double-leaf design of dividing walls is also common in planar prefabricated timber construction. In ceiling constructions, airborne sound insulation and impact sound in particular

prove to be decisive (Fig. 2). The common sound insulation-related decoupling of modules that lie on top of each other by means of elastomeric bearings is highly suitable for this purpose: the selfsupporting ceiling is optimally detached from the above-lying floor and functions similarly to a suspended ceiling. This allows the floor structures to be designed in a relatively uncomplicated manner and usually without the complex combination of wet and heavy fill, otherwise commonly applied in timber construction, resulting in construction height and weight savings. Fire safety

Room module construction doesn’t necessitate special fire safety requirements. The respective provisions of the building regulations and the additional set of rules for timber construction apply. What is important for the definition of requirements is an understanding of the loads acting on the components in case of fire. All load-bearing components must meet the requirements stipulated in the respective building regulation or defined in the project-specific fire safety concept. The module ceiling is, as a rule, not involved in vertical load transfer, though it can be used for reinforcing the building. In this case, it is a load-bearing com­ ponent with an appropriate fire safety requirement. Hence, it must be ensured that the ceiling’s load-bearing capacity is maintained over the required period of fire exposure. It must be assessed with respect to burn-up or alternatively encased in terms of fire safety. If the ceiling of the module is designed as a non-load-bearing component, it can be used as a flammable or non-flammable protective layer for the module floor lying above. In this case, it is also permissible that, in case of fire, ceiling parts fall down after a certain fire duration and that the

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ceiling does not necessarily maintain its load-bearing capacity over the entire fire resistance period. As a rule, the floor structure takes on fire exposure from above, for example in the form of a non-flammable screed, which functions like an encasement. ­Nevertheless, the unfinished floor must be designed to meet the requirement for the fire resistance period in the respective building class. The load-bearing walls of the modules must only be assessed in terms of room-sided flash-over or encased depending on the requirement:

if the joints are filled with non-flammable insulating mats, made of mineral wool, for instance, and in a void-free manner, fire spread in the joint between the room modules is securely precluded. In cases where a utilisation unit consists of several modules, with connecting passages, for example, the walls in this area must be designed for a two-sided fire load (Fig. 3).

tional strategies are compared with each other (Fig. 4, p. 38).

Ceiling constructions

Type 1.1 represents a commonly used construction that meets high sound ­insulation and fire safety requirements. The floor structure of the upper module has a screed, which is decoupled with

The range of ceiling constructions is ­documented below, on the basis of the examples in the projects section (p. 64ff.) and the applied construcFire load from below

Rw

Under type 1, the cross-laminated ­timber constructions are summarised; ­alternatively, other solid timber ceilings, made of glued-laminated or board stack timber, for example, are also conceivable.

Fire load from above

Utilisation unit 1 (UU 1) Encasement or screed burn-up zone Module floor with fire safety requirement Cavity-free insulation – no fire load Module ceiling with fire safety requirement depending on the load-bearing function Encasement or burn-up zone

a

Utilisation unit 2 (UU 2)

Rw EI R

UU 1

Rw

2

Ln,w

R Proof of load-bearing capacity E Proof of spatial enclosure I Proof of heat insulation

Fire compartment R

UU 2

UU 1

UU 1

Cavity-free insulation – no fire load Load-bearing layer of module wall Encasement or burn-up zone 3b

Dividing wall, single-sided fire load

Internal wall, two-sided fire load

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Type 1.1

Type 2

Type 3

Decoupling of sound insulation Type 1.2

Type 1.3

Type 1.4

Type 1.5

4

38

respect to impact sound, and a heavy fill of moderate height. In most cases, dry screeds are used to avoid complicating prefabrication due to drying periods. The fill contributes to sound insulation and also offers the possibility to lay building services conduits on this level. The insulating mat between the base layers is fastened to the lower module. Its contribution to sound insulation rises with increasing layer thickness. In addition, this insulation ensures that the construction remains cavity-free, which represents a significant characteristic from the viewpoint of fire safety, since this precludes fire spread between the modules. The cross-laminated timber ceiling of the lower module is ­visible from below, and if it contributes to a load-bearing capacity in case of fire, it must be accordingly assessed with respect to burn-up. Alternatively, it is possible to directly clad the ceiling with non-flammable panels, in order to encase the load-bearing structure for fire safety purposes, or to simply enable a neutral exposed surface (see the new building extension Hotel Katharinenhof in Dornbirn, p. 72f.). This type is found in residential buildings or hotels. The variation of the construction in type 1.2 can be explained by its use as a school building and by its manufacturing process. Since open room modules are employed in this case, the floor structure must be incorporated on site. For the purpose of an expeditious completion, the structure is minimised here, and a fill is dispensed with, which also has a positive impact on the dimensioning of the load-bearing structure in light of the large spans. The loss in terms of sound insulation is at least partially compensated by the prefabricated, suspended ceiling made of wood-wool slabs, which, however, primarily serves to improve the acoustics of the classrooms.

Types 1.3 –1.5 represent stepwise ­simplifications of the layered structure with a correspondingly lower sound ­insulation level. Type 1.3 also dispenses with an additional fill, though it continues to have two levels of decoupling in terms of sound insulation owing to the floating screed and the module joint. Type 1.4 employs a composite cement screed that ensures fire safety from above and functions as additional storage mass while also improving the ceiling’s vibration behaviour (see the residential complex in Toulouse, p. 89ff.). With respect to a floating screed, sound insulation is considerably poorer. In France, the minimum requirements for impact sound insulation are however relatively low compared to those in most other Central European countries. In type 1.5, with extremely reduced layers, the floor of the upper module simultaneously serves as load-bearing structure, walkable covering, fire safety layer, and in terms of sound insulation, acts – in a sense – like a floating screed. The light beam ceilings of type 2 display an entirely different approach: here, fire safety is ensured by the load-bearing ceiling elements. The multiple layers of both raw constructions, with cladding and insulating layers (mass-spring principle), have a positive effect on sound insulation and, in spite of a low mass, also permit extensive reduction of the floor structure to a walkable covering with light impact sound decoupling. The overall design of these constructions, however, is of considerably greater height compared with the solid timber constructions. In type 3, the manufacturing principle of the field factory makes transportation of the room modules on the road super­ fluous, allowing for a hybrid solution:

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4

5

Type 1

Type 2

Type 3

room modules without a ceiling are assembled directly at the construction site in a weather-protected manner using prefabricated, planar elements. As in a conventional reinforced concrete building, the raw ceiling made of reinforced concrete meets the fire safety requirement and, in conjunction with the floating screed, also that of sound insulation. Dividing wall constructions

The overview in Fig. 5 shows the types used for dividing wall constructions, starting from the simplest construction and reaching up to structures with numerous layers. Types 1– 4 are constructions of crosslaminated timber. The wall thicknesses of the raw construction vary according to the number of floors (2 –7 floors) and a fire application of between 78 and 125 mm per module wall. The planar load-transferring cross-laminated timber generally permits the installation of switches and sockets, even for high fire safety requirements, since only partial disruptions arise in case of fire and the load-bearing capacity (R) of the individual module wall is not impermissibly com­ promised. For the proof of a physical ­barrier (E) and thermal insulation (I), both walls can be added together. The switch boxes and sockets in the module walls must be arranged offset to one another, in order to avoid a burn-through. Despite decoupling in terms of sound insulation, type 1 is only suitable for internal walls with low sound insulation requirements or, conditionally, for meeting min­ imum requirements of dividing walls. In the latter case, project-specific sound measurements are, as a rule, necessary. Types 2 and 3 have additional cladding made of plasterboard, and thus also meet higher sound insulation requirements.

Type 4

 ypology of ceiling structures, schematic drawing, T scale 1:20 Type 1.1 “Wohnen 500” residential complex in Mäder (p. 92f.) Senior citizens’ home in Hallein (p. 84ff.) Refugee accommodation in Hanover (p. 94ff.) Woodie student hostel in Hamburg (p. 80ff.) Hotel Katharinenhof in Dornbirn (p. 72f.) Residential and care home with a ­nursery in Fieberbrunn (p. 69ff.) Type 1.2 European School in Frankfurt am Main (p. 102ff.) Type 1.3 Puukuokka residential complex in ­Jyväskylä (p. 86ff.) Type 1.4 Residential complex in Toulouse (p. 89ff.) Type 1.5 Hotel Ammerwald near Reutte (p. 66ff.) Type 2 Treet residential tower in Bergen (p. 77ff.) Office building in Wabern (p. 100f.) Modular schools in Zurich (p. 97ff.) Type 3 Student hostel in Heidelberg (p. 74ff.) Typology of dividing wall structures, schematic drawing, scale 1:20 Type 1 European School in Frankfurt am Main (p. 102ff.) Type 2 Hotel Ammerwald near Reutte (p. 66ff.) Woodie student hostel in Hamburg (p. 80ff.) Refugee accommodation in Hanover (p. 94ff.) “Wohnen 500” residential complex in Mäder (p. 92f.) Type 3 Puukuokka residential complex in ­Jyväskylä (p. 86ff.) Student hostel in Heidelberg (p. 74ff.) Hotel Katharinenhof in Dornbirn (p. 72f.) Office building in Wabern (p. 100f.) Senior citizens’ home in Hallein (p. 84ff.) Type 4 Residential complex in Toulouse (p. 89ff.) Type 5 Modular schools in Zurich (p. 97ff.) Treet residential tower in Bergen (p. 77ff.) Schematic drawing of module joints

Type 5

While the timber surface remains exposed in type 2, and the cross-laminated timber must therefore be assessed with respect to burn-up, the plasterboard shell in type 3 can also function as fire safety-related encasement.

5

Type 4 allows for further enhancement of the sound insulation level by using flexibly mounted facing shells. In this case, fire safety can be provided by either the building shell or the facing shells. The ­latter variant can be used if conduits can be more easily laid in the installation layer. Type 5, based on frame construction, meets high sound insulation and fire safety requirements, depending on the employed panelling materials.

Building shell In the following section, the principal ­constructions connected to the room module structure, namely external walls, balconies, roofs and plinths, are considered in their basic variants. External wall

In typical room module structures, with load-bearing, longitudinal module walls, the building’s external walls are nonload-bearing. They can then either be designed as timber frame element or as relatively thin cross-laminated timber element with external thermal insulation. If the external walls are, however, conceived to be load-bearing, the total thickness of the wall accordingly increases by the load-bearing layer. The fire safety requirement also depends significantly on whether the external wall is designed to be load-bearing or non-load-bearing. This also applies to a possible contribution of the external walls to reinforcing the building.

6

Facade cladding Facade cladding

Supplementation of wind-proofing, thermal insulation Supplementation of wind-proofing, thermal insulation

Prefabricated room module Prefabricated aroom module

6 b

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Prefabrication including cladding ∫ Highlighting the joint

Prefabrication including cladding ∫ Negating the joint

Prefabrication without cladding ∫ Highlighting the joint

Prefabrication without cladding ∫ Negating the joint

7 a

b

c

d

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7

8 9

 ypology of module joints, depending on the T ­degree of prefabrication (principle sections and exemplary implementation) a Prefabrication including cladding and highlighting the joint (Photo: School, Zurich (CH) 2015, Bauart Architekten und Planer) b Prefabrication including cladding and negating the joint (Photo: Impulszentrum, Graz (AT) 2004, Hubert Rieß) c Prefabrication without cladding and highlighting the joint (Photo: Woodie student hostel, Hamburg (DE) 2017, Sauerbruch Hutton) d Prefabrication without cladding and negating the joint (Photo: Puukuokka residential complex, Jyväskylä (FI) 2015 –2017, OOPEAA) Balcony structure positioned in front, “Wohnen 500” residential complex, Mäder (AT) 2016, ­Johannes Kaufmann Architektur Typical balcony structures, vertical sections, a  Positioned in front, with its own foundation b Suspended 8 c  Cut out or set back

During the technical and aesthetic conception of the facade, the joint between the modules plays an important role. The layers of the thermal insulation, windproofing and facade cladding must be carried across the joint in a continuous fashion. Connecting these layers takes place on site, since a completely pre­ fabricated linkage of all layers cannot be reliably and controllably produced at reasonable expenditure at the plant, and the required steps can, moreover, be completed relatively quickly and without great expenditure on the building site (Fig. 6, p. 39). With regard to the degree of prefabrication of the facades, there basically are two possibilities: • Complete prefabrication, including ­cladding (Fig. 7 a, b): facades of room module structures, including the cladding layer, can be entirely prefabricated on a modular basis, so that only the joints between the modules need to be completed on site. As a result, the joints between the modules can remain distinctly visible, depending on the facade design. The strategy of the accentuated joint is often followed in buildings with a more temporary character. • Retrospective mounting of cladding (Fig. 7 c, d): as a rule, the substructure of the facade cladding is already premounted on the module. Mounting facade cladding only after positioning the modules is advantageous. The wind-proofing of the individual modules can be easily connected and the weather resistance thus achieved is sufficient for the construction phase. Moreover, there is considerably greater freedom in facade cladding design, since the module joints don’t necessarFall Fall1 1 ily have to remain externally visible. The spectrum ranges from solutions with a

complete negation of the component joints (for example, Puukuokka resi­ dential complex in Jyväskylä, Fig. 7 d and p. 86ff.) to the accentuation of the modu­larity as a design idea for the facade (for example, Woodie student hostel in Hamburg, Fig. 7 c and p. 80ff.). The cladding itself can likewise be prefab­ricated in the form of elements and mounted very quickly. Multistorey buildings with flammable facades are required to horizontally interrupt the rear ventilation level at specific distances, depending on the respective building regulations, using steel sheets,

Fall 1 9 a

Fall Fall2 2

Fall 2 b

for example, in order to avoid a chimney effect in case of fire and thus rapid fire spread between the floors. In this case, a horizontal separation between the modules is also required for technical reasons. Balconies, loggias and arcades

In room module construction, thermally decoupled and structurally independent constructions for balconies and arcades have prevailed. The most consistent ­solution here is the frontally positioned balcony with its own foundation, which is only attached to an existing building for positional fixing in a point-based manner (Figs. 8 and 9 a).

Fall Fall3 3

Fall 3

c

41

Layers, Shell and Technology Fall 2

10 a

Fall 3

b

The balconies can also be suspended and the loads transferred via the roof to the load-bearing walls (Fig. 9 b, p. 41). This solution lends itself to use in cases where there is a requirement for a columnfree ground floor (for example, street frontage development, shunting traffic, etc.). The project-specific design and construction of frontally positioned as well as suspended balconies is principally independent of room module construction. It is also conceivable to prefabricate the balconies themselves as a complete spatial unit (Fig. 11). Interesting design possibilities are provided by cutting in loggias or arcades into the building, though this also presents considerable constructional challenges (Fig. 9 c, p. 41). With respect to the load-bearing structure, it seems ­reasonable to design the module walls, in this case, as projecting, wall-like supports. The load peaks from the projection must then be transferred to the floor below with sufficient decoupling for sound insulation reasons. Dispensing with a floor structure on the unfinished floor in the area of the loggia, in contrast to the indoor space, is geometrically interesting, since in this way, a high step from the inside to the outside can be avoided. The load on the module ceiling below, however, fundamentally changes due to the design of the loggia and represents an exception within the system. Quite ­differently, it must transfer considerable live loads and, moreover, be able to ­handle fire application from below and above. The superstructure must meet the agreed requirements concerning impact sound and external noise. The walk-on covering of the loggia must be decoup­ led for sound insulation reasons, and depending on the requirement level, a suspended, flexible shell may additionally be necessary.

11

12

42

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10 Typical balcony structures in floor plans a positioned in front b shortened room module 11 Room modules as balcony structure in front of planar-prefabricated, three-storey timber ­construction on a reinforced concrete plinth, ­WylerPark residential and office building, Bern (CH) 2008, Rolf Mühlethaler Architekten 12 Hotel Katharinenhof, Dornbirn (AT) 2017, ­Johannes Kaufmann Architekten 13 Schematic drawing of possible roof structures a  Flat roof b  Superimposed steep roof structure, warm attic c  Superimposed steep roof structure, cold attic d  Special type, space-filling roof module

a

Decoupled balcony zones can, as already described, be positioned in front of the building or, as a type of loggia, placed in front of a correspondingly shortened room module. In this solution, the double-leaf construction method is geometrically convenient as it is possible to insulate the external walls flanking the balcony in the plane of the second wall shell. The inner wall thus merges with the external wall in a step-free manner, while the elevation of the balcony opening corresponds to that of a facade opening with full glazing (Fig. 10). b

Loggias lying on top of each other, within the modular boundaries, are generally conceivable as well, though they require considerable additional constructional effort (for example, residential complex Puukuokka in Jyväskylaä, Fig. 7 d, p. 40 and p. 86ff.). Special types The extension of the Hotel Post in Bezau, from 1998, includes an unconventional balcony construction. Steel L-sections are mounted in the facade-facing module corners, which – in a projecting manner – transfer the load of the timber balconies c to the module walls (Fig. 14, p. 13). Current requirements for thermal bridge-free constructions and the sophisticated building physics-related penetration of the facade planes have not encouraged further development of such constructions. For the rooms of the extension building of the Hotel Katharinenhof in Dornbirn, completed in 2017, highly compact balconies were desired (Fig. 12; see also ­vertical section, p. 73). These consist of 50 mm thick cross-laminated timber panels, which were rear-anchored to the modules in a thermally separated manner already during prefabrication. Together with the sun protection, they are integrated in and are flush with the metal facade. 13 d 43

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a The roof

In principle, room module construction is suitable for all roof constructions and shapes (Fig. 13, p. 43). In the case of sloping roofs, constructions placed on regular modules as well as special modules with sloping ceilings are conceivable. These must be aligned with the load-bearing structure of the module construction. The roof can, as is common in Scandinavia, be designed as cold roof construction, with thermal insulation on the uppermost module ceiling, or have thermal insulation in the plane of the roof. b

c

Flat roofs are, however, much more common, and as a rule, with warm roof construction. The roof structure, consisting of a vapour barrier, thermal insulation, flat-roof waterproofing and possibly a gravel layer or green roofing, is usually not prefabricated, since it can be fitted considerably more quickly and in a more material-efficient way on site in an areawise manner, following assembly of all the modules. It is not necessary to design the joints between the modules as movement joints in the sealing layers, since the movements between the modules are minimal and can be absorbed by the materials. The edge of the roof is frequently designed as an attic and can also be prefabricated or retrospectively mounted, depending on the module height and hence the transport height as well as other logistical considerations.

14 d

44

For practical reasons, the roof drainage is not led through the module area but is accomplished either as external drainage via roof edge drains and downpipes at the facade; alternatively, the water can be drained by means of an inlying drainage, for example in the corridor area.

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14 Strategies for constructing foundations a, b  Rear-ventilated structure c, d  Base plate of reinforced concrete 15 Impact of the foundation on the appearance of the building (left) and schematic design of details of the foundation, scale 1:20 (right) a Strip foundations, rear-ventilated, beam ceiling with insulation between beams, day-care centre, Innsbruck (AT) 2018, Dietrich | Unter­ trifaller Architekten b Point foundations, rear-ventilated, cross-­ laminated timber ceiling with external thermal insulation, residential complex, Toulouse (FR) 2015, PPA architectures c Reinforced concrete base plate, not rear-­ ventilated, thermal insulation below base plate, “Wohnen 500” residential complex, Mäder (AT) 2016, Johannes Kaufmann Architektur d Reinforced concrete base plate, not rear-­ ventilated, thermal insulation above base plate, European School, Frankfurt am Main a (DE) 2015, NKBAK

Substructures

In projects with special use of the ground floor (as in hotels, etc.), a base level, in solid construction, is often built, whereby the substructure corresponds to that of conventional buildings (see also “Constructing with Timber”, p. 26ff.). The same applies in cases with basements, which are rather atypical for room module ­constructions. For ground floor-level substructures of room module buildings without basements, there are two different strategies: • Rear-ventilated constructions: In rear-ventilated constructions, the lower modules, which are thermally insulated and surrounded by air, are offset from the ground. In terms of the load-bearing structure, point foundations of reinforced concrete or, in the case of small loads and a temporary character, screw foundations can also be constructed. Moreover, strip foundations, partly as prefabricated components and mounted on a castin-place foundation bottom, are suit­ able for rear-ventilated constructions (Figs. 14 a, b). • Reinforced concrete base plates: The modules are mounted on a base plate with a planar position in the soil, which protects from the moisture of the ground, in a cavity-free manner. In doing so, it is possible to place the thermal insulation on or under the concrete plate. The base plate can transfer the loads in a planar manner or span across strip foundations lying underneath (Figs. 14 c, d). The decision on the choice of con­ struction follows a consideration of ­functional, constructional, designrelated and procedural aspects, as well as the planned operating life of the building.

b

c

15 d

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From the viewpoint of design, the basic decision must be taken on whether the building is to be firmly anchored to the ground (construction with base plate; Figs. 15 c, d, p. 45) or appear to be floating (rear-ventilated construction; Figs. 15 a, b, p. 45). The principle of having the load-bearing timber structure begin above the soil also applies to room module construction, and influences the level of the ground floor. A floor level that is as close to the ground as possible supports barrier-free access. Rear-ventilated constructions require additional height for the layer of air. This should be adequately dimensioned to permit overhauls. In order to save superstructure height, the rear ventilation level can be lowered into the terrain and the floor of the lower modules designed as a beam ceiling or box floor so that the thermal insulation and the load-bearing plane are positioned in the same layer. In constructional terms, both individual and strip foundations are highly efficient with respect to the material and hence resource-conserving. Additional effort is required for effective protection against small animals. Rear-ventilated constructions, moreover, complicate prefabrication: in this case, the ground floor-level modules are generally special types and must be prefabricated along with the floor structure underneath the unfinished module floor (external thermal insulation, wind-proofing, protective cladding). This complicates the process in the factory hall on account of more complex storage and logistics. The substructure works are, as a rule, carried out in parallel with the prefabrication of the modules (see also “Process”, p. 50ff.). 46

Depending on the project and seasonal situation, the construction of a reinforced concrete base plate can, however, be time-sensitive. With respect to thermal insulation in winter and in summer, the construction of solid base plates has slight advantages, since the surface in contact with the ground is less encumbered with influxes of heat and cold than in rear-ventilated constructions. The storage mass of the base plate cannot, in general, be activated, since the module floor and the floor structure develop too high an insulating effect. This applies to constructions with the insulation layer both above as well as below the base plate. In summary, it can be concluded that room module construction is trending towards planar substructures. Exceptions are temporary buildings with the desire for minimal and reversible ­sealing.

Building services A major advantage of room module construction is the complete, factory-based prefabrication of all building servicesrelated conduits, control units and transfer points within a module. Ideally, the ­furnishings of the space are also already complete during the module’s assembly, with quality control largely taking place in the factory hall. The extent and type of building servicesrelated features depend on the agreed project standard and are, in principle, independent of room module construction. The possibilities range from the ­simple features of an emergency shelter to the comfort of a high-quality hotel with a controlled ventilation system and airconditioning.

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16 S  haft arrangement and fire protection ­bulkheading

Room module Component with fire safety requirement Firewall for pipes and lines

Shaft routing inside the firewall

Shaft routing in required corridor

Case 1

Case 3

Horizontal fire protection bulkheading

Case 2

Case 4

Vertical fire protection bulkheading 16

47

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Shaft arrangement and fire protection bulkheading

The planning of the building services ­conduits should already be considered in the preliminary design, since it greatly influences the design of the floor plan. Two major factors that building services planning needs to take into account at the outset are the aspects of prefabrication and fire safety. The primary decisions pertain to horizontal or, alternatively, vertical fire protection bulkheading, and the position of the building services shafts (inside or outside the modules; Fig. 16, p. 47). In doing so, the process of assembly also plays an important role. Since the modules are often transported across larger distances, the assembly on site is usually assigned to other sanitary fittings and electrical installation companies rather than to the firms carrying out the prefabrication. A simple interface that can be handled by conventional technology on site is therefore advantageous.

17

If the shafts run inside the modules, all utilities between the modules must be linked using connecting elements in a ­relatively laborious manner and with ­limited working space (or correspondingly large-dimensioned shafts). More­ over, drywall installers and painters must ­complete the remaining tasks for closing the shaft walls. In case 1, it is advantageous if the module floor – and not, in part, the module ceiling – meets all fire safety requirements, since otherwise the connection of the fireproof bulkhead to the lower module is hardly realisable. In case 2, even though the fire protection bulkheading can be prefabricated in the plant, the shaft walls with fire safety requirements must, however, be connected

18

48

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on site at the module joints, which presents major problems in terms of accessibility.

independently of the user via the ­generally accessible circulation area.

These considerations make clear that, in principle, positioning of building services shafts outside modules has major advantages Fig. 16, p. 47, cases 3 and 4): • The modules do not need to be ­accessed following assembly, and hence contamination or damage, as on conventional construction sites, are precluded. • The building services interface is clearly defined: the prefabricating company installs the cubicle up to the lead-through into the shaft zone. Shaft installation is then carried out by a firm on site. • The measures on site can be carried out without special connection means or special knowledge. • Overhauling, maintenance and replacement of installations are carried out

Comparing vertical and horizontal fire protection bulkheading, the vertical one has the advantage that implementations relating to fire safety requirements can already be carried out in the plant, and only the dry construction shells need to be added (Fig. 16, p. 47, case 4). More­ over, the rather complicated provision of horizontal fire protection bulkheading can be dispensed with at the intersection between the module ceiling and the differently constructed corridor ceiling. Case 3 is advantageous for concrete corridor ceilings, since the ceiling lead-throughs are then realisable with conventional fire protection bulkheads. Shafts running outside modules can be either conventionally constructed on site

or likewise prefabricated as elements so that only the connections are provided at the construction site. Installation areas within a module

The area of a module’s ceiling is predestined for ventilation ducts (Fig. 17). In this case, fire safety is to be ensured above the area of installation, for example in the floor of the upper module. Individual electrical lines and sockets or switches can, even in the case of high fire safety requirements, be routed in exposed cross-laminated timber walls (see also “Dividing wall constructions”, p. 39). In more extensively equipped cases, front-wall-based installation structures are recommended (Fig. 18). As in conventional construction, the floor structure primarily routes heating and water pipes as well as electrical lines in fills or levelling layers. Cut-outs in the shell structure for accommodating pipes and lines are to be carefully coordinated with the planning of the load-bearing structure as well as with sound insulation and fire safety. Especially millings transversely to the direction of the top layers of cross-laminated timber as a rule will be problematic, as they considerably limit load-bearing capacity. In adjacent, open room modules, the coupling of water pipes, for example in cases where floor heating extends across more than one module, is possible without difficulty (Fig. 19).

19

17 V  entilation ducts in the ceiling area of the modules, new annex building, Hotel Katharinenhof, Dornbirn (AT) 2017, Johannes Kaufmann ­Architektur 18 Interface of module installations – shaft installation in the corridor area 19 Laying of floor heating pipes in the manufacturing hall

49

Process

Room module manufacture in Europe The development of construction using timber room modules is closely connected with the development of implementing firms in the market. The geographical areas of focus of the corporate landscape are the same as in timber construction in general: leading companies are p ­ rimarily based in Switzerland and Vorarlberg, Austria. In Germany, the highly p ­ roductive competitors are not exclusively but primarily based in the southern part of the republic. Highly developed companies can also be found in Scandinavia and Finland. The number of competitors is still comparatively low today, though considerable growth of the providing firms has been discernible in recent years. A further rise in the market share of this construction method can be expected, as a significant expansion in existing capacities can already be observed. An increasing number of existing, large timber construction companies are gearing up for room module construction as an additional field of activity. While in northern Europe, it is industrialscale companies that determine room module construction, in Central Europe, the sector is developing primarily due to medium-sized timber construction companies. These have established themselves in the construction of room modules, and moreover, also offer a larger range of timber construction-related services. Only a small number of competitors are able to manufacture room modules with complete interior furnishings and building services entirely in-house. A few larger firms are also producing lightweight steel modules in parallel. 1

50

 anufacturing hall at Kaufmann Zimmerei und M Tischlerei in Reuthe (AT)

The production of room modules is ­carried out by companies that work

with different manufacturing options. This includes the size and features of the production hall: joinery facilities, machinery, the dimensions of the workspaces, storage options, as well as ­hoisting equipment inside the hall are major parameters here. The staffing, i.e. the number of employees, the level of education, and the wealth of experience, as well as the network of subcontractors and suppliers are different in every company. These factors influence both logistics and the assembly process, as well as the construction. They determine how many modules can be completed, transported and mounted at what time. The companies are usually geared towards a preferred construction type. In Vorarlberg, for example, the widespread method is to operate with supplied prefabricated, cross-laminated ­timber elements. This makes elaborate machinery for CAM joinery dispensable. The most important production resources for this construction type are the knowhow in planning and manufacture, a wellattuned and trustfully operating network of planners and subcontractors in all trades, sufficiently dimensioned production sites, and efficient conveyor systems in the factory hall. In Switzerland, in particular, there tend to be more firms focusing on the use of timber frame elements. In order to make the process efficient in light of high labour costs, and to enhance value creation in the company, this construction method extensively works with automated production facilities. Here, the application of multifunction bridges, automated framing stations and sometimes gantry robots replaces, at least in building shell construction, manual work by humans to a large extent.

Process

Planning and implementation process A major advantage of room module ­construction is the short project duration, which is why a decision in favour of this construction method is often taken in connection with construction projects that are under high time pressure. In order to be able to use this advantage and ensure an effective procedure, some aspects, especially for project organisation, must be considered and correctly decided upon. Commissioning – contracting and cooperation models

When building with room modules, the following principle, which applies to timber construction in general, is of particular importance: for organisational and economic optimisation, the classic contracting model, with its strictly separated fields

of planning and implementation, can be disadvantageous, since it does not consider the company-specific impact on the construction. It often prevents firms from determining the optimum solution for their options and the respective task, since in room module construction, in particular, there is strong tendency towards company-specific system solutions. In the traditional, prevailing model in Central Europe, with contracting of individual trades and detailed service descriptions, the planning team draws up complete implementation planning following design and approval planning, without including the implementing firms. On this basis, the planning office works out a detailed schedule of services, and the bidders for implementation make their offers with respect to single items. This procedure

causes a number of problems, especially in the field of public contracting. For planning teams without experience in the specific task of room module construction, it is a challenge to determine the timber construction and optimal layer structure for the project, as well as planning these in detail and tendering for them in an equally detailed manner. As a consequence, the architects, who are operating in a legal grey area here, turn to implementing firms to discuss implementation. However, the firms can only serve the architects with their companyspecific know-how. If they subsequently want to participate in the call to tender, the fundamental contracting principle of equal treatment as well as that of transparency, depending on the procedure, is put into question. Hence, a call to tender based on the stipulations of the advising

1

51

Process

2

 chematic comparison of project procedures: S ­solid construction – timber construction – timber room module construction Detail of the example of the European School in Frankfurt am Main (DE) 2015, NKBAK, scale 1:20 a Planning status of the architects for functional tendering b Planning status of the timber construction company for execution

3

company is made public, which, in case of doubt, cannot even participate in the tendering process, which, in turn, other firms can only conditionally respond to. Following the tendering process, complicated feedback loops are necessary for planners and implementers, in order to react to the circumstances of the commissioned firm. For these reasons, the ­traditional contracting process is not used when building with room modules.

A considerably more expeditious proced­ ure with a positive impact on the construction costs, and which is also applied in public contracts, has proven to be a contracting process based on functional tendering (Figs. 2 and 3 a; see also European School in Frankfurt am Main, p. 102ff.): an initial planning team comprising an architect and specialist planners develops planning that accurately describes the aesthetic (surfaces, facade

design, etc.) and functional requirements (load-bearing structure, fire safety, sound insulation, building services concept, etc.) without defining the constructional details of the room modules in a final manner (Fig. 3). On this basis, timber construction companies prepare package offers, which also include these remaining planning services. Hence, the timber construction entrepreneur acts, in part, as a general contractor and assumes a lead-

Building permission

Solid construction Conventional contracting

Design Implementation planning Tendering + contracting Foundation Building shell Shell + fit-out Completion

Timber construction 2D prefabrication Conventional contracting

Design Implementation planning Tendering + contracting Foundation Prefabrication Mounting of timber construction Fit-out Completion

Timber construction 3D prefabrication Contracting following functional tendering

Design Tendering + contracting Implementation planning Foundation Prefabrication Mounting of timber construction Fit-out Completion

2

52

140

Process

3 a

b

ing role in the area of module planning following the building application, while the architect here is mainly entrusted with an advisory and controlling function and coordinates the interplay with building sections not built as room module structures. Depending on the project structure, the interfaces and divisions of labour can be differently designed [1]. This model ensures genuine competition between the providers and creates equal conditions for all bidders. In this way, the principles of public contracting are essentially implemented in a significantly improved manner. However, the principle of supporting the interests of medium-sized companies clashes with the formal obligation to divide lots, i.e. the division of tenders according to trades. This is incompatible with room module construction and must be suspended, in the individual case, by the responsible authority. Though this represents a certain obstacle, it has developed into common practice. In reality, the ­projects are largely implemented within the frame-work of cooperations between medium-sized companies. A fundamentally alternative approach would lie in considerably stronger standardisation of the construction method across company boundaries. For this, however, room module construction, at least currently, is still too firmly in the innovation and development phase.

Producible and transportable module geometries must already be developed in the preliminary design. The respective transport route from the manufacturing site to the assembly site also influences planning. In this respect, and especially in the case of very large room modules, possible variants must be considered and eligible providers ascertained in advance, as well as transport routes examined with regard to narrow sections, etc.

Design planning

Commissioning of all required planners must take place early to ensure integral planning from the start. Early coordination of the spatial design, the load-­ bearing structure and building services is essential. Due to the strong influence the building method exerts on the design and construction, an early decision in favour of or against room module construction is imperative.

A clear and continuous load-bearing structure is a required premise for ­planning. The component dimensions of floors, ­ceilings and dividing walls influence the external dimensions of the ­completed building. These dimensions must be necessarily defined for submission of approval planning, i.e. prior to actual e ­ xecution planning. This requires early determination of the superstructures or at least a geometrical assessment of suitable constructions. By early, integral coordination of the disciplines of architecture, structural design, sound insulation, fire safety and building services, useful and reliable assumptions can be made. Building permission

The official processing time for the approval of building projects is up to six months or more, in practice. For all construction methods, the client and the planning team are responsible for ­taking the decision to commence with implementation planning in parallel. This decision carries a risk, which must be carefully considered for all construction methods equally, from conventionally built masonry to highly prefabricated room module construction. While it is, as a rule, only implementation planning and pos­ sibly the call for tender during the relatively slow process of the conventional construction method which is affected by

this risk, this can also delay implementation during the highly expeditious process of room module construction: already after a few months during which tendering, contracting and implementation planning are pushed ahead, the placement of orders for components with longer delivery periods needs to be ­handled. It is therefore advisable to ­coordinate the project with the approval authority already at the start of planning and to submit the building permit ­application with the principal decisions at an early date. Implementation planning

At the time of contracting a company, a high degree of security in terms of costs and scheduling is achieved, representing a major advantage of this construction method. As a rule, the timber construction company takes on the complete implementation planning, at least for the room modules. The planning team spe­c­ ifies the geometry and surface design of the modules, the building services concept of the entire building, the positioning of building services within the modules, as well as the features and furnishings. All planning decisions required for prefabrication must be taken in a timely manner since otherwise the advantages of prefabrication are compromised. Construction-accompanying planning must be precluded entirely. The planning period for drawing up and coordinating implementation planning normally follows a tight schedule. Hence, planning also follows the ahead-of-­ schedule work for material and component deliveries accordingly: in the case of cross-laminated timber constructions, for example, the definition of these elements has priority, since delivery periods of several weeks are to be expected. The same applies to the window elements. 53

Process

4

5

6

 imber construction and manufacturing hall T at ­Erne a Manufacture of timber-frame elements as shell structure by means of a rail system and ­indoor crane b  Multifunctional bridge Manufacture of complex room modules as ­timber-frame structures using a gantry robot. ­Research project by Erne in c ­ ollaboration with ETH Zurich Manufacturing hall at Kaufmann Zimmerei und Tischlerei in Dornbirn (AT), Architect: Johannes Kaufmann Architektur a Schematic floor plan of goods flow and ­assembly sequence b Room module shell structures made of crosslaminated timber

The application of digital tools is handled in highly different ways, and their future development is currently widely debated. In practice, this considerably depends on the construction method: room modules made of cross-laminated timber don’t necessarily require three-dimensional rendering for manufacture, since the panel manufacturers also offer joinery on the basis of two-dimensional drawing files for the same price. For a highly ­laborious switch to three-dimensional planning, which enables enhancement of objects by additional information and an exchange of the data model with the other planning participants and the user according to Building Information Modeling (BIM), there is not sufficient ­motivation at present. If, by contrast, ­timber frame elements are used in the planning, joinery, which as a rule is ­­­­carried out ­in-house, is almost always CAM-based, making a three-dimensional drawing absolutely necessary. This ­simplifies the step towards further automation. In general, the strongly systemoriented room module construction lends itself well to automation and para­ meterisation of planning. In particular, further potential for time savings in planning is perceiv­able here.

a

4 b

Manufacture

The prerequisites for manufacture are a proficiency and capacity of the timber construction entrepreneur that are appropriate for the project size as well as a punctual and precisely scheduled synchronisation of all subcontractors. Experienced timber construction companies have at their disposal a small and hence well-attuned cluster of subcontracting companies. This has major advantages compared to the conventional contracting of individual trades: the companies collaborate because they work together well and not because they are thrown

5

54

Process

2 3

6 1 2 3 4 5 6 7

Delivery of engineered wood materials Delivery of external construction materials Various stations of serial module manufacture Final inspection and quality control Interim storage Truck loading Delivery to construction site

together in ­random new constellations by the result of tendering. In this way, procedures can be organised in a standardised, effective and well-versed manner. The interlocking processes have a positive impact on quality management, since errors become rarer or are detected ­earlier and more reliably. Building with room modules is always a method involving a maximum degree of prefabrication. The manufacture of the modules, however, reflects the entire spectrum of craftsmanship-based manufacture, i.e. from largely conventional construction, under the protection of the factory hall, ranging up to partially automated production. A high degree of system openness and individuality tends to result in a more pronounced craftsmanship-based manufacture. This method works well for smaller companies. By contrast, large firms, with a high number of projects and units, are able to more strongly automate the process and hence increase efficiency. In doing so, however, a certain amount of at least internal company standardisation is necessary, while flexibility tends to reduce.

1

5

4

7

6 a

recesses, openings and milling works, and hence can be entirely pre­fabricated. All building services conduits are precisely specified, so that the conduits, branches, bends, etc., can be delivered to the factory hall in a prepared condition and mounted in an accordingly expeditious manner. The module is manufactured in a production line and moved – mostly on a track system or simply shifted by an indoor crane – from one ­production stage to the next (Fig. 6). The principal production process of the two most common construction ­methods, i.e. using cross-laminated timber, on the one hand, and timber frame construction, on the other, essentially ­differs only with respect to the timber building shell. The cross-laminated timber elements are delivered in a prefabricated condition and connected to the building shell of the module mostly with self-drilling

screws. Possibly required cladding of walls with plasterboard panels, for example, can be carried out on the ­elements while they still lie on the ground. This prevents less ergonomical assembly. In the case of timber frame elements, the stud frame is initially prepared in the joinery facility and often assembled with the help of semi-automatic framing stations. Planking takes place using multifunctional bridges, which carry out this procedure in a largely automated manner. As a rule, planar elements are manufactured first, and are then manually assembled into room modules. A process currently being developed uses gantry robots to freely position the profiles of the load-bearing structure in space where they can be manually screwed together (Fig. 5). This method is especially suitable for more complex geometries such as roof structures.

The manufacture of timber room modules is already economical at a very small number of units, since there are no disadvantages compared to construction on site. A considerable increase in efficiency is possible at unit numbers starting from approximately 15 identical modules or ones differing from each other in only a few points. At this scale, serial production becomes practical. This differs from ­individual production in several aspects: production planning is considerably more detailed and complex than in individual production. Cross-laminated timber ­panels, for example, are defined with all 6 b 55

Process

a

b

c

d

e

f

7 g

h

56

Process

7

 anufacture of room modules from crossM laminated timber a Basic installation of heating, sanitary and ­ventilation systems b Basic electrical installation c Window mounting d Drywall construction e Paintwork f Floor structure g Tiling work h Floor covering work i Interior fit-out j Transport preparation

Further fit-out of the modules then typ­ ically takes place in the following steps (Fig. 7): 1. Basic sanitary installation: installation of pipes and conduits in the floor, walls and ceilings 2. Basic electrical installation: installation of cable routes and individual cables 3. Mounting of window elements: the time of window mounting is flexible to a certain degree, depending on the connection details 4. Drywall construction: depending on ­project requirements and wall structure, the wall and ceiling cladding and the construction of installation shells as well as shaft and internal walls are carried out. 5. Paintwork: paintwork with several coating and drying phases primarily takes place after drywall construction but is typically distributed across the entire interior fit-out. 6. Floor structure: the procedure depends on the choice of screed system. Dry screeds made of engineered panels best fit into the production process, since there are no drying periods to take into account here. In cases where screeds are installed wet, such as in the form of a cement screed, the construction is to be ­configured according to the drying periods. For this purpose, there are two common procedures: in the first variant, the floor layers, including the screed, are installed prior to the spatial assembly of the module, and the screed is accordingly set aside at the wall connections using temporarily screwed on square timbers. These prepared floors with screeds can then be stored for drying in a space-saving manner. Alternatively, the screed can also be installed in the completed module, which is then set aside for

7 i

j

hardening of the screed, provided that sufficient storage areas and ­corresponding transport systems are available in the hall. 7. Tiling work: construction of wall ­surfaces in kitchens and bathrooms 8. Floor covering work: installation of walkable coverings (parquet, linoleum, etc.) 9. Final installation work: mounting of sockets, switches, sanitary objects and fittings 10. Furniture: mounting of fixed components such as beds, shelves, etc. 11. Facade work: depending on the degree of prefabrication, insulating layers or cladding are already installed at the plant or added on site in the form of prefabricated facade elements. The facade is often prefabricated on the module up to the windproof layer. 12. Ensuring transportability: addition of circumferential driving rain protection; mounting the lifting aids for crane installation; storage prior to transportation Transport

For the construction of room modules, transport is a decisive and even designdetermining procedural phase. For this purpose, special transports, which are subject to approval, are generally employed. The following paragraph serves for orientation with respect to the ­prac­ticability of room module transport. ­Only coordination with a transport specialist at a very early date during the design process ultimately provides planning safety. The actual transport routes are to be examined for each case with respect to local bottlenecks. In doing so, differences pertaining to road construction and approval must be taken into ­account, both on a national as well as ­regional level.

Transportable module size The maximum size of room modules is, on the one hand, predefined by the production facility and conditions on the building site but primarily by the transport possibilities provided by the truck. Lengthwise, a standard semi-trailer truck with a loading length of about 13.50 m already provides sufficient scope for most projects (Fig. 9, p. 59), while ­overlong vehicles also allow for larger lengths at manageable additional expenditure (fig. 8, p. 58). However, a critical length is reached at about 15 m, above which handling the modules becomes increasingly difficult, including during production. In housing construction, height restrictions are rather rare, though these do indeed exist in larger-dimensioned ­modules for school and office buildings: motorway bridges, ­variable traffic signs and guidance s­ ystems as a rule have a clearance height of 5.00 m, while – at least in Germany – drive-through heights of less than 4.50 m are already subject to labelling. The German road network is almost completely designed for drivethrough heights of 4.50 m. A recommended ­maximum total transport height of 4.30 m works relatively reliably across Europe. For the usual loading ­platform heights of 0.90 to 1.10 m, a height of at least 3.20 m thus remains for the modules. Special low-bed ­semi-trailer trucks with cropped loading areas at a height of about 0.30 m permit room modules with a maximum height of 4.20 m with certain restrictions ­concerning the length of the cubicles (Fig. 10, p. 59). Space widths are another limiting factor in the planning process. The law does not 57

Process

2.90 m 2.55 m

3.00 m

3.50 m W  3.50 m H  2.90 m L  12.50 m

Width (W) Height (H) Length (L)

W  2.55 m H  2.90 m L  13.50 m

W  3.00 m H  2.90 m L  30.00 m

Approval

none

Special approvals required Usually perman­ ent permission is available

Escort vehicle

8

Miscellaneous

58

4.00 m W  4.00 m H  3.10 m L  12.50 m

4.20 m W  4.20 m H  4.20 m L  12.50 m

4.50 m W  4.50 m H  4.20 m L  12.50 m

5.50 m W  5.50 m H  4.20 m L  12.50 m

Usually permanent permission is available

An escort vehicle is required on Bundesstraßen (“federal highways”) Always on Autobahnen (“motorways”) in Austria; partly in Germany and Switzerland

Police escort

Transport expenditure A frequently cited argument against room module construction is sup­posedly disproportionately complex transport. Indeed, almost always, less payload per truck can be transported in the case of this construction method than in that of more compactly stackable planar ­elements. However, timber room modules in common sizes often also weigh approximately 350 – 400 kg/m2, so that large room modules of more than 20 t by all means likewise approach the capacity limit of common semi-trailer trucks. In the case of smaller dimensions, with lengths of up to around 6.50 m, it is moreover possible to transport two modules in one vehicle. The average costs for a transport route of several hundred kilometres are currently estimated to be about 5 % of the

4.20 m

construction sites along the way. In cases where transport widths above 4.00 m are r­ equired, a transport study should be commissioned that examines the route from the production site to the destin­ation. For maximum-dimensioned room modules with a width of up to about 5 m, the large sideward overhang beyond the loading area also results in the load-bearing structure becoming ­relevant here. In such cases, it is necessary to either specially consider the issue of transport in planning the loadbearing structure or to utilise auxiliary structures placed ­underneath, such as steel profiles, which in turn, have to be taken into account in terms of the total height. Often the last few metres during transport and the approach to the construction site are the most sensitive points.

3.10 m

stipulate a fixed maximum dimension for the width of large-capacity transports in Germany. However, as transport widths increase, so do the stipulations with respect to the approval process and implementation. Bottlenecks such as thoroughfares and underpasses, roundabouts or temporary narrow sections due to construction sites determine the feasibility of the transport. There is no comprehensive computer-based program that ­records all narrow sections. The standards in road construction are neither ­nationally nor internationally uniform. ­Already at the district level, the road ­network is varyingly developed, and in Germany, there are differences from state to state. Problems during transport can be relatively safely avoided by ­adhering to a total width of 3.25 m and thus also being able to pass unexpected

An escort vehicle is required on Autobahnen (“motorways”); in Austria, double escort

Police escort in Germany and Switzerland

Always with police escort Low-loader truck combinations

Process

 8 T  ransport widths and associated requirements for transport   9 Flat-bed semi-trailer truck for transporting ­modules with lengths of up to 13.60 m 10 A low-bed trailer with cropped loading area ­permits transports of modules with heights above 4.00 m with corresponding restrictions in module length.

pure construction costs. The driving ­distance is not the only deciding factor in this regard. In fact, it is the complexity of the transport (police escort, etc.), which can make itself felt with a price fluctuation of up to 30 %. Complex transports are therefore often carried out in convoys, in order to more effectively use the safety measures. Mounting

Extremely fast mounting of room modules is one of the main advantages of the ­construction method. Since the modules are completely covered in a wind- and driving rain-proof foil for transport, mounting is also possible in bad weather, while protection from water damage is very good. The almost “vertical” time schedule, and strong overlaps between pre­ fabrication and preliminary constructional work on site, requires a very early and continuous coordination of the two areas 9 (Fig. 2, p. 52). Foresighted construction site logistics is a prerequisite for quick mounting. Local obstacles, such as fences and hedges in the approach area are to be localised in good time, and solutions coordinated between the construction supervision, the timber construction company and the transport company prior to mounting. ­Preliminary constructional work, such as foundation-laying or shell construction of the base level must be mandatorily completed and approved. Adherence to the minimum required hardening period of the reinforced concrete, which is sometimes shortened using catalysts due to high time pressure, is to be considered in the schedule. The provision of building services, too, must be completed up to the agreed interface. All components of site facilities required for mounting should ideally be available. The delivery route for the semi-trailer truck must be sufficiently dimensioned and prepared as per the 10 59

Process

accrued wheel loads; likewise, a crane and scaffolding should be available and ready to use. The following steps describe the typical procedure of room module mounting: 1. Preparation of the mounting ground: guidance bars, aligned to horizontal and vertical positions, are placed onto the foundation or the solid ceiling of the ground floor, and are lined with swelling mortar. 2. Mounting of modules: the modules are lifted to their destination point using a crane and statically required fixing measures, such as tensile anchors, etc., are mounted. Possibly present planar corridor elements, which are mounted in between the modules, can likewise be mounted from floor to floor. Using a crane, it is as a rule possible to mount 10 –20 room modules a day, so that mounting for common project sizes can be completed within one to a maximum of two weeks. 3. Providing provisional facade sealing: the horizontal and vertical joints of wind and driving rain sealant are closed as quickly as possible in parallel to the mounting of the modules. As a rule, the room modules arrive at the construction site with overlapping strips, which are then stuck together on site. 4. Providing provisional roof sealing: the ceilings of the modules are likewise covered in a wind- and driving rain-proof film for transport, which is removed during the course of mounting. As soon as all modules are in position, the vapour barrier level is applied, which also functions as an emergency roof. In the case of a flat roof, temporary drainage is usually ­provided by the emergency outlets in the attic. This ensures sufficient weather protection for the building during the mounting phase.

a

11 b

60

Process

11 H  otel, Nördlingen (DE) 2018, Johannes Kaufmann with Kaufmann Zimmerei und Tischlerei a Loading of the room modules onto the ­articulated truck in the manufacturing hall b  Transport of the room modules 12 Mounting of room modules, Hotel in Nördlingen

5. Completion of the building: in conclusion, completion of building services, the fit-out of the corridor zones and – if applicable – the base level, as well as mounting of the missing layers of the roof and facade structure are carried out in parallel. This fit-out phase depends on the construction and the share of conventional building areas, and is usually considerably more timeconsuming than the mounting of the modules themselves. Lifting of room modules is usually carried out by mobile cranes. The maximum ­distance between the delivery point of the semi-trailer truck and the final ­module position determines the crane’s radius, while the interplay of room ­module weight and required hook height determines the dimensioning of the crane. In the case of changing crane locations and delivery points in particu-

lar, it should be ensured that the ground is able to absorb the wheel loads and the loads due to the crane. The use of pressure distribution panels may possibly be necessary. Provided the room modules have sufficient rigidity, they can be directly mounted on the crane hook on four points using steel cables. In the case of less rigid modules, an additional lifting structure may be required – usually in the form of a strong steel frame that provides f­urther attachment points. This especially applies to very large modules or room modules consisting of timber frame elem­ents, which tend to be less rigid than those made of cross-laminated timber. If the facade has a high degree of prefabrication and hence correspondingly less work needs to be done from the ­outside, mobile platforms can be used as work areas. In northern Europe, in ­particular, these mobile means or mast climbing platforms

are also used to a significantly greater extent. In Central Europe, by contrast, fixed scaffolds are more often used, which are – as far as possible – set up prior to the mounting of the modules. This ensures that the required fall protection is already provided during the mounting of the modules and attachment or completion of the facade cladding is possible without difficulty. In buildings with more than two storeys, either relatively complex and expansive self-supporting scaffolds are employed or the scaffold must be set up in sections that follow the progress of module mounting. In this case, the scaffold can be accordingly back-anchored on the module structure. Note: [1] Kaufmann, Hermann et al.: leanWOOD – ­Optimierte Planungsprozesse für Gebäude in vorgefertigter Holzbauweise. Technische Uni­ versität München 2017. www.holz.ar.tum.de/­ fileadmin/w00bne/www/leanWood/leanWOOD-­ Broschuere.pdf

12

61

Decision Aid: Pros and Cons of Room Module Construction

There are basic parameters that show – already during the project development phase – whether room module construction is appropriate for a given case. This chapter is to serve as decision-making support with respect to the pros and cons of this construction method, whereby the weighting of the individual parameters not only depends on the objective specifications of a project but also on the sometimes subjective analysis of the decision-makers. Fig. 1 distinguishes between three stages of decision-making parameters: • The required basic prerequisites must be completely fulfilled in order to make room module construction possible, especially in technical and design terms, in the first place. • Advantageous framework conditions list parameters favouring an increase in efficiency compared with a conventional construction method. If most of these parameters can be answered in the affirmative, the application of room modules can be considered appropriate with high probability. • Expounding the explicit strengths, the most persuasive arguments are stated that – if they apply to the respective project – explain why it is predestined for room module construction considering the abovementioned parameters. Required prerequisites

1. B  asic suitability of the project for timber construction: At least in Germany and due to fire safety reasons, the lowest common denominator is formed by the classification into the building classes 1– 5, thus excluding high-rise buildings. For the building classes 4 and 5, very early coordination with a fire safety expert is recommendable, in order to estimate the effort required for ensuring fire safety. 62

2. M  odule-based realisation of the brief: The programme should, either entirely or to a large, definable part, be implementable in terms of identical or similar module units of transportable size (see “Transport”, p. 57ff.). The base level is often solidly constructed to organise the special functions of the programme (for example, in the hotel lobby, seminar rooms, etc.). 3. L  inear load transfer: Modular construction very strongly favours linear load transfer via the transverse or longitu­ dinal walls of the modules. The load axes should, at least in the area of the modules, run across floors uninterruptedly and not require load diversions that are difficult to accommodate in the applied construction method. 4. O  penness towards modular construction by all participants: The planning team (especially the architect, structural engineer, building services planner) should have skills in prefabricated timber construction and the client should at least be open towards the construction method. 5. S  ufficient advance planning: Planning periods in room module construction are, as a rule, shorter than for other construction methods (see “Process”, p. 50ff.). A ­sufficient advance period is required since planning must be unconditionally completed prior to the start of production and constructionaccompanying planning is to be avoided in any case. 6. Interest from implementing firms: Prior to the start of planning, it should be enquired whether implementing firms with sufficient capacity and expertise are available, since bottlenecks, at least currently, often occur here.

Advantageous framework conditions

1. High ecological quality demands: CO2 storage, primary energy savings for building construction, as well as a dismantling and recycling ability are the main arguments in favour of timber or room module construction. 2. The desire for exposed timber surfaces: The haptic and optical quality of exposed timber surfaces is an important argument for many clients and users, in particular. 3. Number of identical modules above 10 –15: from this quantity onwards, serial production with the set-up of a production line begins to make sense, in which the modules proceed from station to station, significantly increasing the effectivity of production. Nonetheless, even at lower quantities and at least with respect to conventional timber buildings, there is no disadvantage. 4. The room module corresponds to the utilisation unit: Double-layer walls and ceilings meet the sound insulation and fire safety requirements, thus increasing the effectiveness of room module construction. 5. Room modules that can be fully pre­ fabricated: The efficiency of room ­module construction increases when the fully equipped modules are, ideally, sealed in the manufacturing hall, and are only opened for use. In this case, the construction of connections to adjacent room modules is not necessary, the installation of building services within the module is completed, and reinforcements for transport or mounting are not required. 6. Extensive equipping of module areas: Building services work, in particular,

Decision Aid: Pros and Cons of Room Module Construction

3. Low-emission construction site: Compared to conventional construction sites, the mounting of modules is not only fast but also emits considerably lower emissions in terms of noise, shocks, dust or smell. These advantages become particularly important when construction work is to be carried out in existing buildings, or in a highly dense urban or especially sensitive environment.

strongly benefits from effective prefabrication in the manufacturing hall due to its high material requirement and frequent quality controls. 7. O  penness towards functional tendering: Conventional contracting of building services on the basis of a detailed description of services is currently an obstacle due to a lack of standards for modular construction. Public clients, in particular, must therefore be won over to alternative contracting methods (such as a functional description of services). 8. H  igh cost security requirement: ­Following execution planning, a high degree of cost security is ensured due to planning depth and predicta­bility of processes, which in conventional construction methods is only achievable with lump-sum ­contracts and corresponding risk surcharges.

4. H  igh execution quality: The quality of execution is considerably increased by complete prefabrication in the manufacturing plant and is, above all, sig­ nificantly more effectively controllable.

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 onsecutive parameters for decision-making with C respect to the pros and cons of timber room module construction

Required prerequisites ∫ Room modules possible 1. Basic suitability of the project for timber construction 2. Module-based realisation of the brief 3. Linear load transfer 4. Openness towards modular construction by all participants 5. Sufficient advance planning 6. Interest from implementing firms

Explicit strengths

1. Temporary character and high recyc­ lability requirement: More than any other construction method, building with room modules is suited to temporary uses, as well as extendable or scaled-down building concepts and the shifting of entire buildings. 2. Short construction period: The entire project duration is considerably shorter compared to other construction methods (see “Process”, p. 50ff.), and mounting is carried out extremely expeditiously. Therefore, room module construction is always particularly ­sensible in cases where there are advantages due to a short construction period (such as hotel extensions with loss of income, addition of floors in operational buildings, etc.).

Advantageous framework conditions ∫ Room modules sensible 1. High ecological quality demands 2. The desire for exposed timber surfaces 3. Number of identical modules above 10 –15 4. The room module corresponds to the utilisation unit 5. Room modules that can be fully prefabricated 6. Extensive equipping of module areas 7. Openness towards functional tendering 8. High cost security requirement

Explicit strengths ∫ Room modules predestined 1. Temporary character and high recyclability requirement 2. Short construction period 3. Low-emission construction site 4. High execution quality 1

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Project Examples

  66 Hotel Ammerwald near Reutte (AT) Oskar Leo Kaufmann and Albert Rüf, Dornbirn   69 Residential and Care Home with a Nursery in Fieberbrunn (AT) sitka.kaserer.architekten, Saalfelden   72 Hotel Katharinenhof in Dornbirn (AT) Johannes Kaufmann Architektur, Dornbirn / Vienna   74 Student Hostel in Heidelberg (DE) LiWooD Management AG, Munich   77 Treet Residential Tower in Bergen (NO) ARTEC, Bergen   80 Woodie Student Hostel in Hamburg (DE) Sauerbruch Hutton, Berlin   84 Senior Citizens’ Home in Hallein (AT) sps÷architekten, Thalgau   86 Puukuokka Residential Complex in Jyväskylä (FI) OOPEAA, Helsinki    89 Residential Complex in Toulouse (FR) PPA architectures, Toulouse   92 “Wohnen 500” Residential Complex in Mäder (AT) Johannes Kaufmann Architektur, Dornbirn / Vienna   94 Refugee Accommodation in Hanover (DE) MOSAIK architekten, Hanover   97 Modular Schools in Zurich (CH) Bauart Architekten und Planer AG, Bern / Neuchâtel /Zurich 100 Office Building in Wabern (CH) W2 Architekten, Bern 102 European School in Frankfurt am Main (DE) NKBAK, Frankfurt am Main

Hotel Ammerwald near Reutte (AT)

Architects:

Oskar Leo Kaufmann and ­Albert Rüf, Dornbirn Contributors: Bernd Riegger (project management) Matthias Reichert, Eva ­Hagmayer Structural engineers: Mader & Flatz, Bregenz (solid construction) merz kley partner, Dornbirn (timber construction) Timber construction Bidding consortium: company: Kaufmann Zimmerei und Tischlerei, Reuthe Kaufmann Bausysteme, ­Reuthe Completion: 2009

This hotel, located near Lake Plansee at an elevation of 1,100 m above sea level, is primarily used as a seminar hotel. The room modules are placed on a twostorey, L-shaped plinth, which accom­ modates the common uses. These base levels, like the three stairwells, are constructed in reinforced concrete in order to meet the requirements of snow depths in winter and static as well as fire safety aspects. The three upper floors are very efficiently accessed by a central corridor and ­primarily consist of 96 room modules, which contain the rooms. The quality of these spaces develops from their materiality: the cross-laminated timber of the

construction forms all surfaces. The floor has also been left without any ­further structures, while also dispensing with a decoupled screed. This results in a space-saving construction with a reduced number of layers. Only in the particularly humid bathroom areas is the timber protected by a transparent coating. The construction of the corridor comprises cross-laminated timber panels that elastically rest on the cubicles, and – due to the screed and cladding with plasterboard – meet the fire safety and sound insulation requirements. Owing to the double-leaf walls and ceilings, as well as

the joint-facing, direct plasterboard cladding, the required airborne noise and impact sound insulation values can be met. For the prefabrication of the room modules, a dedicated production line with twelve manufacturing stations was installed. It was possible to produce the modules, as far as interior furnishings and curtains in a total of 31 days. The building services conduits, too, were ­pre-mounted and only connected with each other on site. The assembly of the modules on the construction site took ten days. The stainless steel facade was only fitted on site, in order to preclude damage to the sensitive surface during transport and assembly. The timber con13 12

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struction method within building class 5 and the partly exposed timber surfaces do not in all respects correspond to the prevailing building regulations. In this regard, the project-specific fire safety concept defines some compensatory measures: the fire compartments are considerably smaller than the permissible limit, while the emergency escape routes have a maximum length of 20 m. Additionally, an extensive fire alarm system has been installed. The fire resistance duration of the load-bearing structure is 60 minutes. Due to its new scale and architectural quality, the project created a strong impetus for timber room module construction.

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  1 Gravel, 60 mm Sealing bituminous sheeting, three layers, 11 mm Thermal insulation, PUR hard foam without gradient, 200 mm Vapour barrier Cross-laminated timber, five layers, 140 mm, oiled on the inside   2 Glazed door: larch, with thermal insulation glazing Single-pane safety glass, 6 mm + cavity, 16 mm + Single-pane safety glass, 6 mm, U = 1.1 W/m2K   3 Railing, aluminium profile, 25/6 mm, welded, painted   4 Stainless steel panel, 2 mm, smoothed Three-layer slab, larch, 42 mm OSB panel, 12 mm Thermal insulation, mineral wool, 64 mm Vapour barrier Thermal insulation, mineral wool, 64 mm mounted on site (module joint) Vapour barrier Thermal insulation, mineral wool, 64 mm OSB panel, 12 mm Three-layer slab, larch, 42 mm   5 Stainless steel panel, 2 mm, smoothed with rear ventilation, mounted on site   6 Squared timber with Sylomer strips, 12 mm   7 Cross-laminated timber, three layers, 60 mm, oiled on the inside Mineral wool, 50 mm Air layer, 30 mm (module joint) Cross-laminated timber, five layers, 140 mm Coating, polyurethane resin, 1 mm (in the bathroom)   8 Panel joint with connection piece, Three-layer slab, 27/160 mm, four rows of screws   9 Roof /ceiling panel, mounted on site 10 Facing shell, plasterboard, mounted on site 11 Cross-laminated timber, five layers, 95 mm, oiled on the inside Plasterboard panel, 12.5 mm Mineral wool, 50 mm Air layer, 15 mm (module joint) Plasterboard panel, 12.5 mm Cross-laminated timber, five layers, 95 mm, oiled on the inside 12 Windproof membrane, thermal insulation, mineral wool Three layers, 380 mm Vapour barrier Cross-laminated timber, three layers, 72 mm, oiled on the inside

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Residential and Care Home with a Nursery in Fieberbrunn

Residential and Care Home with a Nursery in Fieberbrunn (AT)

Architects:

sitka.kaserer.architekten, Saalfelden Contributors: Andreas Planegger (project management), Norbert Haiden, Andreas Schwarzenberger Structural engineers: merz kley partner, Dornbirn (timber construction) FS1 Fiedler Stöffler, Innsbruck (solid construction) Timber construction Kaufmann Bausysteme, company: Reuthe Completion: 2011

The building is situated in the largest ­locality of the Pillersee Valley on a sloping plot above a thoroughfare, and is accessed from above by a side road. The brief of the social centre encompasses a senior citizens’ and nursing home with 80 care places, a day-care facility for senior citizens with a café and a nursery with four groups. The building has been developed by subtractions from an elongated cuboid, into which three atriums are incised. This results in a volume that meanders around the courtyards. In constructional terms, it is clearly sub­divided into three parts, namely a central area made of reinforced concrete, which houses atriums, circulation, common areas and ancillary functions, and east- and westoriented zones with a total of 78 care rooms attached on both sides. In the area of the nursery, a second cross-laminated timber ceiling has been arranged above the modules for load distribution purposes. The roof is constructed as a hollow box ceiling. The nursery c ­ onsists of planar cross-laminated timber e ­ lements and is located on the uppermost level, with its own access from the road. The load-bearing structure of the central zone comprises a reinforced concrete skeleton with projecting ceilings on both sides, which form the access zones. The care room modules have a floor space of 3.79 ≈ 7.60 m. The cross-laminated timber in the rooms has been left exposed. Floorto-ceiling fixed glazing provides a visual link from the bathroom to the care room. The modules were entirely prefabricated, including the furnishings, while the modular timber facade was ­retrospectively ­installed. The project is characterised by its intensive local reference, and demonstrates the architectural-constructional potential of hybrid construction methods with respect to timber room modules and wide-span, reinforced concrete skeletons in an exemplary manner.

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Entrance to care home Atrium Living area Room Storeroom Entrance to residential home Kitchen Café Terrace Eat-in kitchen Entrance to nursery Group room

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Residential and Care Home with a Nursery in Fieberbrunn

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Sun protection: Frame, aluminium, 1,950/3,500 mm, electric movable, cladding larch wood rough-cut, varnished, 24 mm Facade: Casing, larch, slot and 13 12key, 11 rough-cut, plank widths 80, 100, 120 mm 7 Battens, horizontal, 60/40 mm Wall mounting of module: Battens, vertical, 60/40 mm /rear ventilation 8 Windproof membrane Wood fibreboard, diffusible, moisture-resistant, 15 mm Cross-wise battens, 100/60 mm, in between mineral fibre clamping felt, 200 mm Cross-laminated timber, three layers, 76 mm, room-facing surface with UV protection varnish Opening casement of glazed door: Timber frame with aluminium clamping profile and triple insulating glazing Aluminium sheeting, powder-coated, 2 mm Fixed glazing: wooden frame with aluminium clamping profile and triple insulating glazing Interior wall, module: Cross-laminated timber, five layers, 95 mm Room-facing surface with UV protection varnish Plasterboard, 12.5 mm Mineral wool, 35 mm Plasterboard, 12.5 mm Plasterboard, 12.5 mm Cross-laminated timber, five layers, 95 mm Mineral wool, 60 mm Cross-laminated timber, five layers, 95 mm

Residential and Care Home with a Nursery in Fieberbrunn

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6 Plasterboard, 12.5 mm Floor structure of module, standard floor: Parquet, oak, 12 mm Chipboards, 2≈ 19 mm Impact sound insulation, 25 mm Vapour barrier Layer of chippings, 74 mm Cross-laminated timber, three layers, 120 mm Sylomer support, 12 mm Threshold, solid construction timber, 67 mm, ­insulation in between Ceiling structure of module: Cross-laminated timber, three layers, 81 mm, room-facing surface with UV protection varnish Floor structure of bathroom: Tiles, 10 mm Screed, 62 mm 10 Vapour barrier Soft fibreboard, 10 mm Cross-laminated timber, three layers, 120 mm Sylomer support, 15 mm Thermal insulation XPS, 60 mm Sealing Reinforced concrete, 400 mm Floor structure of module, ground floor: Parquet, oak, 12 mm Chipboards, 2≈ 19 mm 13 Impact sound insulation, 25 mm 7 Vapour barrier

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Hotel Katharinenhof in Dornbirn (AT)

Johannes Kaufmann Archi­ tektur, Dornbirn / Vienna Contributors: Michael Wehinger (project management), Iris Priewasser, Christos Hantzaras (construction management) Structural engineers: merz kley partner, Dornbirn Timber construction Kaufmann Zimmerei und company: Tischlerei, Reuthe Completion: 2017

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The building, centrally located in Dornbirn, is an extension of an existing hotel. The prescribed, extremely short construction period resulted in the use of room module construction. The basement of reinforced concrete houses an underground car park. The ground floor, likewise constructed in reinforced concrete, accommodates the reception, lobby, kitchen, breakfast room and the access to the existing building. The three upper floors house 39 hotel rooms in a four-star cetegory, for which three ­different module types (single room, standard double room, superior double room) were developed. The stairwell and lift shaft were also prefabricated as room modules in timber. The urbanlooking building does not reveal its ­timber construction at first sight: at the request of the client, the construction of cross-laminated timber was clad in plasterboard on the inside. This layer improves sound insulation and represents a fire safety-related encasement of the load-bearing structure. Ventilation ducts and outlets are integrated into the ceilings of the extensively equipped modules. A homogeneous metal facade covers the reinforced concrete base and the room modules, thus underlining the rigour of the building structure. A deep incision of the volume emphasises the entrance. The sloping, recessed glazed facades of the hotel rooms create niches for small balconies. Their load-bearing structure, a slender cross-laminated timber panel, is equipped with sealing and covered by a grid. The balconies were already prefabricated along with the modules. Only the facade skin was added on site. Prefabrication of the modules took four weeks. The modules were mounted on the base within three days. The total construction period, including for the basement, was only six months. 72

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Hotel Katharinenhof in Dornbirn

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10 Vertical sections Scale 1:20   1 Roof structure: Gravel, 50 mm Sealing, bituminous sheeting, two layers Thermal insulation, PUR insulating panels, 60 mm Thermal insulation, EPS, 60 mm Gradient insulation, EPS, 20 –140 mm Vapour barrier Cross-laminated timber, five layers, 120 mm Plasterboard, 15 mm   2 Aluminium panels, smoothed, strip-anodised, 3 mm, glued to substructure Z-profile /  rear ventilation, 38 mm, windproof membrane   3 Battens, vertical, 60/120 mm, and horizontal, 60/120 mm, thermal insulation in between, ­mineral wool, 240 mm Wall structure of module: Cross-laminated timber, three layers, 80 mm Plasterboard, 2≈ 15 mm   4 Floor structure of module, 2nd floor: Vinyl, 12 mm Chipboard, 2≈ 19 mm Vapour barrier Impact sound insulation, 30 mm Layer of chippings, 40 mm, trickle protection fleece Cross-laminated timber, five layers, 120 mm Thermal insulation, 60 mm   5 Ceiling structure of module: Plasterboard, 15 mm Cross-laminated timber, three layers, 70 mm   6 Suspended ceiling, acoustic panel, MDF, painted on substructure, 62 mm Reinforced concrete, 380 mm   7 Floor structure, ground floor: Tiles, 10 mm Screed, 70 mm Impact sound insulation, 30 mm Thermal insulation, 140 mm Fill, 35 mm Reinforced concrete, 350 mm   8 Facade, ground floor: Aluminium panels, smoothed, strip-anodised, 3 mm, glued to substructure Z-profile /  rear ventilation, 38 mm, windproof membrane Substructure battens, vertical, 60/120 mm, and horizontal, 60/80 mm, thermal insulation in between, mineral wool, 200 mm Reinforced concrete, 200 mm Plaster, 2 mm   9 Sun protection, textile screen 10 Wood-aluminium window with triple insulating glazing 11 Grating, metal, 30 mm, on wooden substructure Rubber granulate Sealing, bituminous sheeting, two layers Plywood panel, 50 mm Solid construction timber, 50/160 mm Aluminium panels, smoothed, strip-anodised, 3 mm Glued on substructure Z-profile 12 Steel profile, L 40/40/3 mm 13 Fall protection: Upper flange, flat steel, 60/30mm, bb Steel rod, powder-coated, Ø 10 mm

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Student Hostel in Heidelberg (DE)

Architects:

LiWooD Management AG, ­Munich Manfred Gruber (freelance ­architect) Contributors: Daniel Friedrichson (project management) Structural engineers: dHb Dürauer Herrmann ­Brändle Tragwerksplaner, Eningen unter Achalm Timber construction LiWooD Heidelberg AG & company: Co. KG, Munich Completion: 2013

The Heidelberg students union commissioned a general contractor on the basis of a competition to construct 158 flats for a total of 265 students. The basic module, with a 3.40 m ≈ 6.60 m footprint, can be used as a single flat, while two to four modules can also be combined to form flats for several students or young families. The room modules, weighing approximately 20 t, have a hybrid construction, which utilises the advantages of the respective materials: the ceilings are made of prefabricated reinforced concrete components and the walls of cross-laminated timber. The manufacturing process also significantly influenced the construction: in a so-called field factory, the timber ­elements, prefabricated reinforced concrete components, building services ­elements, etc., which were delivered by local subcontractors, were assembled into open-top room modules directly on site, and subsequently mounted with a mobile crane. In this way, it was possible to complete six modules per day. Conical wooden dowels at the top of the walls served to position the room modules during mounting. Built-in steel components couple the ceiling elements into a rigid slab, which is connected to the reinforced concrete stairwells. The corridor ceilings also consist of prefabricated parts resting on acoustically decoupled supports projecting out of the module ceilings. Increased sound insulation, as per DIN 4109, is achieved. The project’s overall implementation, complying with the requirements of building class 4, is highly fire-resistant. The cross-laminated timber walls are encased in K230 gypsum fibreboard, while the overall building component achieves REI 60. The facade cladding as well as the furnishings were mounted after the positioning of the modules. The construction period, starting from the upper edge of the base plate up to occupation, was five months. 74

Floor plan, ground floor, Building II

Student Hostel in Heidelberg

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Student Hostel in Heidelberg

Vertical sections of facades Horizontal section of modular facade Horizontal section of modular wall of corridor Scale 1:20 1   1 Wall structure: 2 Cement fibreboard, 8 mm Battens /rear ventilation, 30 mm Windproof membrane 3 Battens, horizontal, 60/60 mm, thermal insulation in between, mineral fibre, solid construction ­Timber, vertical, 4 60/180 mm, thermal insulation in between, mineral fibre8 Encasement, gypsum fibreboard, 18 mm 9 5 Cross-laminated timber, three layers, 110 mm Encasement, gypsum fibreboard, smoothed painted, 18 mm   2 Sound-insulated mount, 5 mm 6   3 Steel profile, galvanised, 150/150/12 mm   4 Titanium zinc sheeting, profiled, 1.5 mm, above 2nd floor d as fire barrier d   5 Front-mounted roller shutter   6 Plastic windows7 with triple insulating glazing   7 Fall protection: flat steel frame, 40/8 mm, 10 with palings of flat steel, 40/4 mm   8 Fire safety grouting   9 Cross-laminated timber, three layers 10 Floor structure: Linoleum, 5 mm Screed with integrated floor heating, prefabricated part, 65 mm Impact sound insulation, prefabricated part, 20 mm Ceiling panel, prefabricated reinforced concrete component, painted 180 mm 11 Module joint for flat dividing wall: Encasement, gypsum fibreboard, smoothed, painted, 18 mm Cross-laminated timber, three layers, 110 mm Thermal insulation, mineral fibre, 50 mm Cross-laminated timber, three layers, 110 mm Encasement, gypsum fibreboard, smoothed, painted, 15 mm 12 Module wall of corridor: Encasement, gypsum fibreboard, smoothed, painted, 18 mm Cross-laminated timber, three layers, 110 mm Encasement, gypsum fibreboard, 18 mm Substructure, metal, 32/32 mm Thermal insulation, mineral fibre, 190 mm Substructure, metal, 32/32 mm Plasterboard (sound insulation), 2≈ 18 mm Battens, 30/60 mm Cement fibreboard, 8 mm 13 Supply shaft

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Treet Residential Tower in Bergen

Treet Residential Tower in Bergen (NO)

Architects: Contributors:

ARTEC, Bergen Marina Trifkovic (project management) Structural engineers: SWECO Norge AS, Oslo Timber construction Kodumaja (modules) company: Moelven (glued-laminated ­timber, cross-laminated timber) Completion: 2015

Located directly on the shore of an ocean inlet outside the city of Bergen, it was the tallest timber building in the world at the time of its completion. The residents of the 62 flats enjoy views of the port and the surrounding fjord landscape, especially from the roof terrace. A reinforced concrete plinth jutting into the embankment accommodates 14 timberconstructed floors. Eleven two-room flats with a living area of 42 m2 respectively, are each housed in one module, while the 51 three-room flats, at 62 m2 per flat, are arranged into two combined modules each. a

On the closed sides of the facade, the frame is filled in with frame-construction

elements and clad in weatherproof ­structural steel. The glazed facades of the two balcony sides protectively envelop the primary structure, while forming an energetic buffer zone and improving sound insulation with respect to the neighbouring, heavily used bridge. The modules, produced in Estonia, were delivered by sea. This is what made ­possible the very large module dimensions (maximum width of 5.30 m). With the exception of the balconies, all timber surfaces are encased or treated with fire safety coatings. The building has a sprinkler system.

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Floor plan, standard floor Section Scale 1:500 Isometric drawing without scale

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Treet Residential Tower in Bergen

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 1 S  teel sheeting, weatherproof construction steel, 3 mm Substructure, steel profile /rear ventilation   2 Secondary load-bearing structure, glued-laminated timber, 148/48 mm  Air layer, tolerance zone 30 mm Thermal insulation, mineral wool, 250 mm   3 Module wall: Plasterboard, 13 mm Timber frame, solid construction timber, thermal insulation in between, 45 mm Vapour barrier Timber frame, solid construction timber, thermal insulation in between, 120 mm Thermal insulation, 30 mm Windproof membrane OSB panel, 8 mm   4 Window reveal, aluminium panel, anodised, 50 mm   5 Wood-aluminium window with insulating glazing   6 Floor structure: Parquet, 14 mm on underlay, 2 mm Acoustic underlay, 7 mm Chipboard, 22 mm Timber frame I-joist, thermal insulation in ­between, 300 mm Plasterboard, 9 mm, windproof membrane Battens, 36/20 mm   7 Steel profile as structural reinforcement Special floor   8 Module ceiling: Plasterboard, 15 + 12 mm Battens, 21/70 mm Timber frame, solid construction timber, thermal insulation in between, 120 mm Chipboard, 18 mm Battens, 19 mm, insulation in between   9 Post-and-beam facade, loggia: Aluminium profiles with single-pane glazing 10 Ceiling, loggia: Cross-laminated timber, five layers, untreated, 161 mm 11 External wall of module: Casing, horizontal, pine, painted, 19/145 mm Battens, 30 mm Windproof membrane Thermal insulation, 30 mm Timber frame, solid construction timber, thermal insulation in between, 45 mm OSB panel, 8 mm Timber frame, solid construction timber, thermal insulation in between, 120 mm Vapour barrier Timber frame, solid construction timber, thermal insulation in between, 45 mm Plasterboard, 13 mm 12 Column, glued-laminated timber, 1,100/400 mm 13 Cross-laminated timber, five layers, 120 mm 14 Inner wall of module: Plasterboard, 13 mm Vapour barrier Timber frame, solid construction timber, 95 mm, thermal insulation in between OSB panel, 8 mm Insulation, 100 mm 15 Panel, anodised aluminium 16 Ventilation 17 Column, glued-laminated timber, 500/500 mm

Treet Residential Tower in Bergen

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Woodie Student Hostel in Hamburg (DE)

Architects:

Sauerbruch Hutton, Berlin Louisa Hutton, Matthias ­Sauerbruch, Juan Lucas Young, J­ ürgen Bartenschlag, Sibylle Bornefeld, Bettina ­Magistretti Structural engineers: Wetzel & von Seht, Hamburg (solid construction) merz kley partner, Dornbirn (timber construction) Timber construction Kaufmann Bausysteme, company: Reuthe Completion: 2017

The hostel, operated by a private investor, is located in the district of Wilhelmsburg. With its 371 student flats, it is currently the largest residential building made of timber room modules. The main access to the building is provided by a heavily used ­pedestrian pathway and cycle path, above which the upper floors of the comb-like structure project out. An expressive, table-­ like, reinforced concrete structure above the largely open ground floor houses service functions and a café. The E-shaped floor plans of the six upper floors are ­accessed by a central corridor, with the exception of the short side corridors in the cantilevering parts. 20 % of rooms are wheelchair accessible; these modules are slightly longer than the standard modules. The stairwells were constructed in reinforced concrete, in order to meet the fire safety and building reinforcement requirements. The corridor areas consist of prefabricated r­ einforced concrete components, to which the modules are attached for the transfer of the horizontal forces. The installation conduits run in the corridor area. The timber construction company was ­involved at a very early stage and, following optimisation of the timber construction planning, was awarded the execution contract. A production line with 17 stations completed four modules a day. Using low loaders, two 6.30 m ≈ 3.30 m modules could be transported from Austria to Hamburg at a time. Due to the confined conditions on site, the modules were ­delivered to the construction site on ­demand. It was possible to mount twelve modules per day, while the modular ­timber facade was mounted later. The total construction period on site was ten months. The timber construction, in building class 5, with exposed timber surfaces, required deviations from the building regulations. The load-bearing structure of the modules has, as per burn-up assessment (REI 90), fireproof dimensioning. 80

Woodie Student Hostel in Hamburg

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 ross-laminated timber, five layers, 125 mm C Plasterboard, 15 mm Thermal insulation, mineral wool, 50 mm Plasterboard, 15 mm Cross-laminated timber, five layers, 125 mm Tiles, 7 mm, sealing Plasterboard, 12.5 mm Cross-laminated timber, three layers, 80 mm Plasterboard, 15 mm Installation space, 410 mm Plasterboard, 2≈ 12.5 mm Prefabricated column, reinforced concrete, 200/350 mm Facade panel, larch, pre-greyed, 26 mm Battens /rear ventilation, 60 mm Sheathing membrane

Woodie Student Hostel in Hamburg

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Cross-wise battens, thermal insulation in between Mineral wool, 200 mm Cross-laminated timber, five layers, 125 mm Wooden windows Red Grandis with triple ­insulating glazing, sound-insulation glass Extensive greening, 80 mm Sealing, plastic sheeting Gradient insulation, 40 – 200 mm Thermal insulation, 200 mm Emergency sealing, bituminous sheeting Prefabricated ceiling, reinforced concrete, 160 mm Natural rubber, 0.4 mm Epoxy resin primer Cement screed, 50 mm PE film

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Load-distribution panel, gypsum, 10 mm Levelling fill for installations, 115 mm Prefabricated ceiling, reinforced concrete, 160 mm Aluminium sheeting, powder-coated, 2 mm Battens / rear ventilation, 30 mm Sheathing membrane Battens, thermal insulation in between Mineral wool, 200 mm Cross-laminated timber, five layers, 125 mm Natural rubber, 0.4 mm Chipboard, 2≈ 19 mm Impact-sound insulation, 30 mm PE film, layer of chippings, 60 mm Cross-laminated timber, three layers, 80 mm Thermal insulation, mineral wool, 70 mm Cross-laminated timber, three layers, 60 mm

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Senior Citizens’ Home in Hallein (AT)

Architects:

sps÷architekten Simon Speigner, Thalgau Contributors: Melanie Karbasch (project management), Dirk Obracay, Sabrina Wallinger, Geraldine Mesko, Waltraud Schernthaner, Barbara Brandstätter, Gaby Mayer, Benjamin Psaltopoulos, Dominik Waggershauser Structural engineers: merz kley partner, Dornbirn (timber construction) BauCon, Zell am See (solid construction) Timber construction Kaufmann Bausysteme, company: Reuthe Completion: 2013

Back in 2008, the architects had won a competition with their suggested urban developmental design: an L-shaped ground plan leaves the major part of the plot free for a park – this area had previously been completely built on with the preceding building. The competition entry envisaged a solid construction. The time savings thanks to prefabricated construction and the commitment to implement the room module construction in a costneutral manner, made corresponding replanning possible at a relatively late date, when approval planning for the solid construction variant had already been compiled. The building has a partial basement. The ground floor, with spaces for common use, was conventionally built of reinforced concrete and provided with a planar ceiling panel above the ground floor, while the stairwells also consist of reinforced concrete. The 136 rooms, comprising cross-laminated timber room modules, are organised into four upper floors. The modules were prefabricated with the complete interior fit-out, while the building services run along the corridor in installation shafts built on site. The modules were thus able to remain sealed from the time of mounting to completion. Insulated timber frames, positioned between the module ceiling and the above module floor, form the substructure for the balconies that lend the facade a sculptural appearance. The copper cladding, like the sun protection, was mounted later on site. The prefabrication of the modules took place within 2.5 months in a hall that was specially rented for the project. They were transported at night. It was possible to mount 10 to 12 units per day. Hence, mounting of the room modules only took a few weeks, and the total construction period, including the demolition of the preceding building, was slightly more than 1.5 years. 84

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Sylomer mount, 12 mm 13 Ceiling structure of module: Cross-laminated timber, three layers, varnished, 78 mm Solid construction timber, 140 mm, thermal insulation in ­between, mineral wool, 164 mm Sylomer mount 14 Corridor wall of module: Plasterboard, 12.5 mm Cross-laminated timber, five layers, 134 mm Utility shaft, 425 mm 15 Door leaf, oak, painted, 69 mm 16 Ceiling structure of ground floor: Thermal insulation, mineral wool, 100 mm Reinforced concrete, 300 mm Suspended ceiling, plasterboard 17 Sun protection: external blinds Slats, aluminium 18 Oak, solid, painted, 50 mm 19 Wall structure of module: Single-pane safety glass, 6 mm, enamelled on substructure Wind-proofing Battens, horizontal and vertical, 2≈ 50 mm, thermal insulation in between, mineral wool Cross-laminated timber, three layers, 95 mm Plasterboard, 15 mm Dry plaster

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Puukuokka Residential Complex in Jyväskylä (FI)

Architects: Contributors:

OOPEAA, Helsinki  Anssi Lassila (project management) Jussi-Pekka Vesala, Iida ­Hedberg, Juha Pakkala Structural engineers: SWECO, Helsinki (timber ­construction) Heikki Löytty, Lauri ­Lepikonmäki Timber construction Stora Enso, Helsinki company: (modules) Completion: 2015 (Building 1), 2017 (Building 2), 2018 (Building 3)

The first eight-storey, timber-built residential building in Finland is a pilot project of the urban planning authority to create ecologically high-quality and, at the same time, cost-effective flats: the tenants make a moderate down payment and become the owners of their flats after 20 years. The project distinguishes itself by an innovative application of room modules: in every flat, the facade-facing spatial layer, consisting of a bedroom, a living room and a loggia, is accommodated in one room module, while a second module houses the inside zone, with bathrooms, kitchens and ancillary spaces. Installations are integrated into the c ­ orridor walls, enabling independent maintenance. The first construction phase was ­completed in only nine months. This ­represents an essential advantage under Finnish climatic conditions. The room modules were delivered with the complete interior fit-out and external wall structure, including wind-proofing. The modular prefabricated timber ­cladding was mounted later. The room module construction is hardly recognis­ able behind the highly sculptural facade. The road-facing facades are made of black-painted spruce wood. The western side, oriented towards a grove on the confined plot, is untreated larch wood. On this side, balconies that project out of the facade alternate with glazed ­loggias, extending the living rooms of the smaller flats. The building has a sprinkler system. The walls of the flats and stairwells are clad in plasterboard; the wooden surface has been left exposed on the ceilings of the flats, as well as on the floor covering in the white stairwells. 86

Puukuokka Residential Complex in Jyväskylä

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Residential Complex in Toulouse

Residential Complex in Toulouse (FR)

Architects:

PPA architectures, Toulouse Guillaume Pujol (project ­management), Alonso M ­ arquez Medina Structural engineers / Pyrénées Charpentes, Timber construction Agos-Vidalos company: Completion: 2015

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In the north of Toulouse, on Place des Papyrus, 50 flats were built to provide cost-effective housing space and support the integration of socially disadvantaged persons. Simply by turning groups of modules, an interestingly staggered building structure was created that ­skillfully responds to the confined plot. By dispensing with four modules on the ground floor, it was possible to accommodate a spacious entrance area. The access space is as interesting as it is effective: a compact spiral staircase made of reinforced concrete and a lift are connected to a repeatedly bending corridor, which is partly lit by the external facade. Two module sizes, each 3.50 m wide and 6.55 m or 7.275 m long, comprise the flats. Adjacent to the lift, each flat is extended using a special module. Supported by individual foundations, the modules are linked to each other by steel panels with welded pegs. While the walls are clad in a plas­terboard shell, the white-varnished c ­ ross-laminated ­timber ceilings remain exposed. In the uppermost modules, they are mounted in the gradient of the flat roof so that a uniformly thick insulating layer could be applied on site. The front facades were prefabricated with glazing and s­ liding a panels of grey-coated aluminium sheet. The4mounting of the room modules took place following the completion of the staircase tower and7 in module group 5 across all four floors, respectively, phases within ten days. Completion took approximately a further 1.5 months. The thermal 1 insulation layer was prefabricated and mounted in building-high timber-frame panels, while the aluminium sheet was 2 1 7 applied later. The module construction did not require scaffolding – all work was carried out from mobile elevating platforms. a

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Corrugated sheet, aluminium, 0.8 mm Battens, horizontal, 25/38 mm Windproof membrane, diffusible Thermal insulation, mineral wool, 140 mm Vapour barrier Cross-laminated timber, three layers, 80 mm Plasterboard, painted, 12.5 mm Sealing, bituminous sheeting, two layers Thermal insulation, mineral wool, 260 mm Vapour barrier Cross-laminated timber, three layers, varnished, 60 mm, partly with gradient PVC tiles, glued, 6 mm Concrete screed, 40 mm Cross-laminated timber, five layers, 120 mm Thermal insulation, mineral wool, 30 mm Cross-laminated timber, three layers, varnished, 60 mm Connecting element, flat steel, 10 mm, with alignment pins, steel, Ø 30 mm, welded

Residential Complex in Toulouse

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“Wohnen 500” Residential Complex in Mäder (AT)

Architects:

Johannes Kaufmann Archi­ tektur, Dornbirn / Vienna Contributors: Isabelle Groll (project ­management) Structural engineers: merz kley partner, Dornbirn Timber construction Kaufmann Bausysteme, company: Reuthe Completion: 2016

A charitable housing society from Vorarlberg has succeeded in combining costeffective and ecologically high-quality as well as well-designed housing. The design is a variant from a differentiated room module construction catalogue of the ar­­ chitects. The name “Wohnen 500” refers to the rent plus ancillary costs (in euro) for a 65 m2 flat. Both the modular construction and restriction to essentials permitted a reduction in construction costs. For example, a basement and a lift are dispensed with. The compact building structure also influences energy consumption; the heating demand is only 34 kWh/m2 per year. A flat consists of three modules arranged in parallel, while four L-shaped flats form the roughly square overall ground plan (see also Fig. 8 b, page 18). On the ground floor, instead of two flats, the entrance area as well as the building services and storage rooms have been accommodated. The modules themselves serve to stiffen the building. The prefabricated reinforced concrete components of the flights of stairs and ceilings rest ­linearly on a cross-laminated timber shell. Their double-layer wall structure, facing the flats, ensures good sound insulation values. The installation shafts are arranged on the side of the corridor and are closed using dry construction (REI 60). The cross-laminated timber panels of the dividing walls of the flats were clad in plasterboard panels at the module joints for sound insulation reasons. The space-facing timber is left exposed and white-varnished. The module walls are designed to be ­fire-resistant (REI 30). The vertical, untreated board planking of the facade was mounted later. The boards continuously run across one and a half floors, and create a facade image that is independent of the module joints. The building concept has already been applied multiple times in the region. 92

Section • Floor plan of upper floor Scale 1:200

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  1 Facade cladding: Cladding with changing rabbets, silver fir, rough-cut, 24 mm Battens, horizontal, 40/60 mm Battens, vertical, 40/60 mm /rear ventilation   2 Wall structure of module: Windproof membrane Solid construction timber, horizontal, 60/80 mm, insulation in between, mineral wool Solid construction timber, vertical, 60/80 mm, insulation in between, mineral wool Cross-laminated timber, five layers, 100 mm, white-pigmented on the room-facing side, joints glued as vapour barrier   3 Module joint, dividing wall between flats: Cross-laminated timber, five layers, 100 mm, white-pigmented Plasterboard, 15 mm Insulation, 30 mm Air layer, 20 mm Insulation, 30 mm Plasterboard, 15 mm Cross-laminated timber, five layers, 100 mm, white-pigmented   4 Module joint, interior wall: 2≈ cross-laminated timber, five layers, 100 mm, white-pigmented   5 Roof structure: Gravel, 60 mm, protection fleece, film seal, 1.8 mm Insulation, mineral wool, 40 –160 mm, gradient 2 % Insulation, mineral wool, 160 mm Aluminium, welded bituminous sheeting Cross-laminated timber, three layers, 100 mm   6 Beam, steel profile, galvanised, 100/60/6.3 mm   7 Column, steel profile, galvanised, 70/70/4 mm   8 Wooden window, grey-painted, with triple glazing   9 Fall protection: battens, silver fir, 40/50 mm, on steel angle, ­galvanised, 75/50/6 mm 10 Prefabricated concrete part, 140 –160 mm, gradient, 20 mm 11 Floor structure of upper floor: Parquet, oak, 10 mm Chipboard, 2≈ 19 mm Impact-sound insulation, 30 mm, PE film Layer of chippings, 80 mm Cross-laminated timber, three layers, 100 mm Insulation, mineral wool, 72 mm Cross-laminated timber, three layers, 60 mm 12 Floor structure of ground floor: Parquet, oak, 10 mm Chipboard, 2≈ 19 mm Impact-sound insulation, 30 mm, PE film Layer of chippings, 80 mm Cross-laminated timber, three layers, 100 mm Air space, 92 mm Sealing, bituminous sheeting Foundation plate, reinforced concrete, 220 mm Perimeter insulation, 100 mm

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Refugee Accommodation in Hanover (DE)

Architects:

MOSAIK architekten, Hanover Structural engineers: Drewes + Speth, Hanover (design) merz kley partner, Dornbirn (timber construction) Timber construction Kaufmann Bausysteme, company: Reuthe Completion: 2015

In connection with the increased demand for refugee housing in 2015, the archi­ tectural firm was commissioned with the planning and short-term implementation of a total of three temporary accommoda­ tion blocks in the Hanover region. In the ­district of Linden-Nord, three two-storey housing rows accommodate a total of 96 rooms, organised into three and fiveroom shared flats. The flats consist of two or three modules with a footprint of 2.70 ≈ 12 m. The central eat-in kitchens serve as entrance, lounging space and distribution zone. The room adjoining the eat-in kitchen is equipped with a doubleleaf door so that, in case of possible sub­ sequent use, this individual space can be converted into a living room. At the heart of the complex is also a ­two-storey community and administration building in room module construction. The shell of the module structure consists of cross-laminated timber. Only the floor of the lower modules is made of a tier of beams with intermediate insulation to save structural height. The modules trans­ fer the loads to strip foundations and are rear-ventilated at the bottom. Small-animal protection for the rear-ventilation open­ ings at the plinth is provided by simple gratings. Arcades consisting of prefabri­ cated reinforced concrete components on steel columns provide access to the upper floor. These are positioned in front of the module structure in a statically independent manner and are screwed to the modules only for fixing purposes. Drainage of the warm roof is ensured by roof-edge drains at the lower points and by external downpipes. The cross-laminated timber remains vis­ ible in the flats. The front facades with their colourful glazed panels were pre­ fabricated. The project duration – from the commissioning of the architects up to completion – was ten months. 94

Refugee Accommodation in Hanover

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Modular Schools in Zurich

Modular Schools in Zurich (CH)

Architects:

Bauart Architekten und Planer AG, Bern / Neuchâtel / Zurich Willi Frei, Raffael Graf, Stefan Graf, Peter C. Jakob, Emmanuel Rey, Yorick Ringeisen Structural engineer: Ruggli & Partner Bauingenieure, Zurich Timber construction Blumer-Lehmann AG, Gossau company: Completion: 1st generation 1998 – 2012, 2nd generation since 2012

The Züri-Modular system, which offers temporary spaces for schools, nursery schools and day-care centres, was ­developed in 1998 by architects who ­already had extensive experience with room module construction. In 2012, the second generation of the system was ­created, which accommodates the increased requirements with respect to space demand and energy savings, and makes possible up to three-storey buildings. The basic structure of the ­design consists of two classrooms per floor. These are connected via a central area including a cloakroom, toilets

and a group room, and are vertically ­accessed by an external stairwell. The classrooms are lit from both sides and can thus be used largely independently from local conditions. The load-bearing walls have a timber-frame structure and are clad in plasterboard. The ceilings have been provided with perforated acoustic elem­ents. The construction also incorporates aspects of reusability and the degree of prefabrication is very high. The building loads are transferred to individual foundations. The facade cladding of untreated timber was prefabricated in the manufacturing plant and

only the joints between the elements are closed on site. The ­double box ­ceiling meets the sound ­insulation ­requirements, while a floating screed is not necessary. Hence, only the floor ­covering of the classrooms, consisting of three open modules, was applied on site. The proven modular system is an integral part of Zurich’s classroom planning. The buildings can be easily dismantled and moved. To date, more than 1,000 modules have been employed at around 60 locations in the metropolitan area of Zurich, and further locations are planned until 2025.

Sections • Floor plan of standard floor Scale 1:400

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Modular Schools in Zurich 7 7 7

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Modular Schools in Zurich

Horizontal section • Vertical section Scale 1:20  1 M  odular wall structure, timber-frame construction: Three-layer slab, larch, untreated, 19 mm Battens, 30/70 mm, rear ventilation Windproof membrane Solid construction timber, 60/80, thermal insulation in between Solid construction timber, 60/180, thermal insulation in between with vapour barrier Three-layer slab, spruce, varnished, 19 mm   2 Facade panel, mineral wool, pressed, 8 mm   3 Wooden window with insulating glazing   4 Wood fibreboard, 16 mm   5 EPDM profile   6 Acoustic three-layer slab, spruce, varnished, 16 mm Solid construction timber, 60 mm, thermal insulation in between, sheep’s wool Three-layer slab, 42 mm Module joint Three-layer slab, 42 mm Solid construction timber, 60 mm, sheep’s wool in between Acoustic three-layer slab, spruce, varnished, 16 mm   7 Roof structure: Trapezoidal sheet, 1.5 mm Substructure, steel profiles, rear ventilation, 80 – 400 mm Windproof membrane Thermal insulation, mineral wool, 180 mm   8 Modular ceiling, timber-frame construction: Wood fibreboard, 16 mm Edge beam, glued-laminated timber, 200/200 mm, tier of beams of solid construction timber, 60/160 mm, in between, with thermal ­insulation, mineral wool, 160 mm Film Slatted frame, 40 mm, thermal insulation in between, sheep’s wool Acoustic fleece Three-layer slab, spruce, 19 mm, with acoustic perforation   9 Sun protection blind, textile 10 Windowsill, three-layer slab, painted, 27 mm 11 Floor structure of upper floor: Linoleum, 2.5 mm Timber-frame construction element: Three-layer slab, spruce, 40 mm Beam, glued-laminated timber, 200 mm, thermal insulation in between, mineral wool, Three-layer slab, spruce, 27 mm 12 Compressed tape, 20 mm 13 Modular ceiling, timber-frame construction: Three-layer slab, spruce, 19 mm, with acoustic perforation Acoustic fleece Battens, 40/60 mm, thermal insulation in between, sheep’s wool Edge beam, glued-laminated timber, 200 mm 14 Floor structure of ground floor (Module / Substructure) Linoleum, 2.5 mm Three-layer slab, spruce, 40 mm Beam, glued-laminated timber, 200 mm, thermal insulation in between, mineral wool Cement-bonded chipboard, 12 mm 15 Support, column, steel profile, 200 mm 16 Individual foundation, reinforced concrete

99

Office Building in Wabern (CH)

Architects: Contributors:

W2 Architekten, Bern Adrian Wiesmann (project management), Jan Micha Thielmann Structural engineer / ERNE AG Holzbau, Timber construction Laufenburg company: Completion: 2009

The extension of asylum interview department of the Swiss State Secretariat for Migration saw the approval of fifty new offices in 2008. These were to be constructed within a short time on a brownfield plot of the Secretariat as a temporary measure for at least ten years. The brief primarily asked for individual ­offices, which were required to meet high sound insulation requirements due to the confidential conversations. This ­favoured the application of room module construction, also considering the very tight schedule. The modules have a frame structure and are prefabricated, including the interior fit-out. The walls are clad in gypsum fibreboards. The ceilings are partly suspended, and a proportion of the smoothed OSB panels were left exposed. The building envelope and building services meet the Swiss Minergie standard. The modules rest on four strip foundations in the area of the corridor walls and exterior walls, and extend across the entire building depth of 14 m. In terms of their width, they follow an axial grid of 2.45 m. The static system also allows for the formation of broader spaces: since the dividing walls between the offices are nonload-bearing, it was also possible to deliver the modules in an open condition or with a dividing wall in the centre of the module. The facade cladding consisting of large-scale, dark-varnished Douglas fir plywood panels was already mounted in the manufacturing plant. The facade strips do not reveal the applied construction method at first sight; only the sheeting installed in the area of the module joints between the floors is an indication. The project’s total duration of six months was very short, the actual construction period took three months in total. In 2013, the building was extended by a further four-storey wing and a partial addition of floors. 100

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Office Building in Wabern

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Section • Floor plan of standard floor Scale 1:300 Horizontal section • Vertical section Scale 1:20

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Roof structure: Extensive greening, 60 mm Drainage protection sheeting Sealing, plastic sheeting Thermal insulation, EPS, 40 –140 mm Vapour barrier Module, timber-frame construction: OSB panel, 25 mm, nail-press-glued Solid construction timber, Duobalken beam 60/240 mm, 120/240 mm Thermal insulation, mineral wool, 240 mm Gypsum fibreboard, smoothed, 15 mm Suspended ceiling sails with heating and cooling function Sun protection: aluminium slats Wooden windows with insulating glazing Wall structure of module: Plywood panel, Douglas fir, rough-cut, 15 mm Battens, 50/60 mm, rear ventilation Timber-frame construction element: Wind-proofing; gypsum fibreboard, 15 mm

 7  8  9

10 11

 olumn, solid construction timber, Duobalken C beam, 60 /200 mm, thermal insulation in between, mineral wool, 200 mm Vapour barrier Gypsum fibreboard, smoothed, 15 mm Ventilation device with heat recovery Grating for weather protection and ventilation: Aluminium slats Floor structure of module: linoleum, 2.5 mm Screed element with impact-sound insulation, 30 mm Timber-frame construction element: OSB panel, 25 mm, nail-press-glued with beam, solid con­ struction timber, Duobalken beam, 60/240 mm, 120/240 mm, insulation in between, 140 mm OSB panel, 15 mm, nail-press-glued Cavity insulation, mineral wool, 40 mm Ceiling structure of module, timber-frame ­construction: gypsum fibreboard, 15 mm Beam, solid construction timber, Duobalken beam 60/240 mm, thermal insulation in between, mineral wool, 140 mm

OSB panel, 15 mm, nail-press-glued 12 Interior wall structure of room / corridor: Gypsum fibreboard, smoothed, 2≈ 15 mm Glued-laminated timber, 120 mm, for reinforcement Gypsum fibreboard, 15 mm 13 Door leaf, 58 mm: core, oak, solid, in between high-density f­ibreboards 14 Module joint, facade: Beam, solid construction timber, Duobalken beam, 80/200 mm 15 Aluminium sheet, profiled 16 Dividing wall, timber-frame construction: Gypsum fibreboard, 15 mm, smoothed Column, solid construction timber, Duobalken beam, 60/80 mm, thermal insulation in between, mineral wool, 80 mm Wind-proofing; module joint, 50 mm Wind-proofing; thermal insulation, 80 mm Column, solid construction timber, Duobalken beam, 60/80 mm Gypsum fibreboard, 15 mm, smoothed

101

European School in Frankfurt am Main (DE)

Architects:

NKBAK, Frankfurt am Main Nicole Kerstin Berganski, ­Andreas Krawczyk Contributors: Simon Bielmeier, Larissa Heller Structural engineers: Bollinger + Grohmann, Frankfurt am Main (solid construction) merz kley partner, Dornbirn (timber construction) Timber construction Kaufmann Bausysteme, company: Reuthe Completion: 2015

A short-term extension of the existing school became necessary due to the ­restructuring of the European Central Bank. The new building could only be approved as a temporary structure and was realised within a period of 17 months, from the planning request to the start of use. The timeframe of the public building project was made possible by an innovative contracting model with functional tendering. 400 pupils are taught here in preschool and primary school, each in their own zone. The design already provided for the extension of the primary school on the northern side, which was realised in the mean-

102

time. The architects combined the modules with corridor ceiling elements and glazed facades, resulting in differentiated spatial sequences and alternating singleand double-wing development, as well as different views of the outside spaces. The design is based on a 3 ≈ 9 m grid, accommodating classrooms, ancillary spaces, sanitary areas and stairwells, which are constructed entirely out of cross-­ laminated timber room modules. The ceiling panels of the corridors are positioned between the modules or rest on glued-­ laminated timber columns. Three modules form one classroom each. Joists made of

highly loadable beech wood laminated-­ veneer timber span the modules in a ­longitudinal direction. The weatherproof building shell was built in 3.5 weeks from the base plate onwards, and completion took two months. The modules were prefabricated along with visible interior surfaces, windows and building services conduits. Merely the floor structure and the aluminium facade were added on site. The building fulfils a fire resistance dur­ation of 30 minutes. Only in the colourfully designed stairwells does the cross-­ laminated timber have a fire safety cladding, in all other areas it is left untreated.

European School in Frankfurt am Main

Isometric drawing of mounting sequence Section • Floor plans Scale 1:500  1  2  3  4  5  6  7  8  9 10

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Main entrance Classroom Teachers’ room Material room Canteen Food-reheating kitchen Storeroom Movement space Group room for preschool Corridor for playing

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2nd floor

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European School in Frankfurt am Main

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European School in Frankfurt am Main

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20 Vertical sections • Horizontal section Scale 1:20   1 Roof structure (on site): Sealing, plastic sheeting Gradient insulation, EPS, min. 120 mm  2 Module: Vapour barrier Cross-laminated timber, three layers, 80 mm Mineral wool, 50 mm Wood wool acoustic panel, 25 mm Beam, laminated veneer timber, beech, 360/220 mm   3 Channel, film sheet   4 Facade cladding (on site): Aluminium sheet, painted, 1 mm Windproof membrane Mineral wool, 120 mm   5 Laminated veneer timber, beech, 360/120 mm   6 Wood-aluminium window with fall protection ­integrated into the frame   7 Floor covering, classroom: Linoleum, 2.5 mm (on site)  8 Module: Chipboard, glued, 2≈ 16 mm Impact-sound insulation panel, 25 mm Cross-laminated timber, three layers, 80 mm   9 Mineral wool, 60 mm 10 Module, ceiling of classroom: Beam, laminated veneer timber, beech, 360/220 mm Wood wool acoustic panel, 25 mm Mineral wool, 60 mm Cross-laminated timber, three layers, 60 mm 11 Cross-laminated timber, three layers, 100 mm Acoustic insulation, 50 mm Acoustic panel, perforated 12 Floor covering of corridor: Linoleum, 2.5 mm (on site) 13 Module: Chipboard, glued, 2≈ 16 mm Impact-sound insulation panel, 25 mm Cross-laminated timber, three layers, 80 mm Installation space, 265 mm Mineral wool, 60 mm Wood wool acoustic panel, 25 m 14 Support, squared timber, 100/200 mm 15 Module: Chipboard, glued, 2≈ 16 mm Vapour barrier, impact-sound insulation panel, 25 mm, cross-laminated timber, three layers, 80 mm Mineral wool, 80 mm 16 Base plate, reinforced concrete, 300 mm 17 Covering, laminated veneer timber, beech 18 Column, laminated veneer timber, beech, 120/360 mm 19 Cross-laminated timber, three layers, white, ­varnished, 80 mm 20 Mineral wool, 30 mm 21 Ceiling-mounted radiator

7

8

9

10

105

106

Appendix

Authors

Wolfgang Huß

Matthias Kaufmann

Konrad Merz

Prof. Dipl.-Ing. Architekt

Dipl.-Ing. (FH)

Dipl.-Ing.

1994 – 2000 Architecture studies at the Technical University of Munich (TUM) and ETSA Madrid, graduated from TUM in 2000. 2000 – 2007 Worked with SPP Sturm, Peter + Peter in Munich 2007– 2016 Research assistant for TUM’s chair for design and timber construction, headed by Prof. Hermann Kaufmann, working in research and teaching since 2013 architectural firm HKS Architekten, with Martin Kühfuss and Christian Schühle since 9/2016 Professor for industrialised building and manufacturing engineering at Augsburg University of Applied Sciences

1998 – 2004 Higher Technical Education Institute (HTL) in Rankweil, in the field of structural engineering 2004 Carpenter at Kaufmann Zimmerei und Tischlerei GmbH 2005 – 2006 Voluntary social year with the Red Cross in Egg 2006 – 2008 Technician at Kaufmann Bausysteme in Reuthe 2008 – 2010 Project realisation at Bere Architects in London 2010 – 2012 Extra-occupational distance learning in civil engineering at the HTWK in Leipzig 2016 – 2017 Extra-occupational examin­ ation for the master’s certificate in timber construction since 2010 Working in the family firm Kaufmann Zimmerei und Tischlerei GmbH 2017 Joins management team at ­Kaufmann Zimmerei und Tischlerei GmbH

1984 Degree in civil engineering at the University of Applied Sciences and Arts Northwestern Switzerland 1995 Degree in business ­engineering 1984 –1986 Project manager at a ­glued-laminated timber manufacturing company 1986 –1990 Assistant at the Laboratory for Timber Constructions, ETH Lausanne 1990 –1993 Senior Structural Engineer, MacMillan Bloedel Research, Vancouver, Canada since 1994 Managing director at merz kley partner, AT-Dornbirn /CH-Altenrhein since 2015 Course head of the universitybased überholz course at the University of Art and Design Linz

107

Appendix

Literature

Absatzförderungsfonds der deutschen Holzund Forstwirtschaft (ed.): Energieeffiziente Bürogebäude. holzbau handbuch, Series 1, Section 2, Part 4, June 2009 Arbeitsgemeinschaft Holz e. V. et al. (ed.): ­Industrie- und Gewerbebauten. holzbau handbuch, Series 1, Section 8, Part 3, ­December 2001 Bereuter, Martin; Robert Fabach et al.: ­Holzmodulbau, booklet accompanying the exhbition in the Werkraum Bregenzerwald. Andelsbuch 2016 Dworschak, Gunda; Wenke, Alfred: Der neue Systembau. Düsseldorf 1999 Huth, Steffen: Bauen mit Raumzellen. ­Analyse einer Baumethode. Wiesbaden / Berlin 1975 Janser, Andres: Raumzellen für Modul-Holzbausystem. In: Schweizer Ingenieur und ­Architekt, 13/1996, p. 9 –12 Junghanns, Kurt: Das Haus für alle. Zur Geschichte der Vorfertigung in Deutschland. Berlin 1994 Kapfinger, Ott; Wieler, Ulrich (ed.): Riess Wood³ Modulare Holzbausysteme. ­Vienna 2007 Luchsinger, Christoph: Raumzellen. Über­ bauung Hurdacker, Dübendorf 1996 –1997. Architects: Werner Egli, Hans Rohr, Baden. In: Werk, Bauen + Wohnen 04/1998 p. 36 – 41 Noel, Matthias: Des Architekten liebstes Spiel. Baukunst aus dem Baukasten. In: Figurationen 01/2004 p. 23 – 40 Pracht, Klaus: Holzbausysteme. CologneBraunsfeld 1981 Raumzellen aus Kunststoffen für ein- und mehrgeschossige Bauwerke. Architekten Ralf Schüler und Ursulina Witte, Berlin 1967. In: Das Werk. Architektur und Kunst. Architektur und Kunst 06/1968, p. 358 – 359 Schärli-Graf, Otto: Eine Methode des industrialisierten Bauens: Raumzellen. In: Wohnen 01/1969, p. 10 –12 Staib, Gerald; Dörrhöfer, Andreas; Rosenthal, Markus: Elemente + Systeme. Modulares Bauen. Entwurf, Konstruktion, neue Techno­ logien. Munich and others 2008 Stucky, Fritz; Meuli, Rudolf: Mehrfamilienhaus nach System Elcon. Das Werk. Architektur und Kunst 04/1966 Technische Universität Berlin, Lehrstuhl für Entwerfen, Prof. Oswald Mathias ­Ungers: Wohnungssysteme in Raumzellen.

108

Picture Credits

Brochure for the seminar. Headed by Joachim Schlandt. Berlin 1969 Tulamo, Tomi-Samuel (ed.) et al.: smartTES. Innovation in timber construction for the modernisation of the building envelope. ­Munich 2014 Wachsmann, Konrad: Holzhausbau – Technik und Gestaltung. Berlin 1930 Wachsmann, Konrad: Wendepunkt im Bauen. Wiesbaden 1959

The authors and the publisher sincerely thank everyone who has contributed to the pub­ lication of this book by providing illustrations and artwork, granting permission to reproduce their documents, or providing other information. All the drawings were specially produced for this publication, those in the project examples section on the basis of architectural drawings. Non-documented photos were taken from the archive of the architects or the archive of the journal Detail. Despite intensive endeavours, we were unable to establish copyright ownership for some photos and illustrations; however, copyright is assured. Please notify us accordingly in such instances. Title

Woodie Student Hostel in Hamburg (DE) 2017, Sauerbruch & Hutton Photo: Thomas Ebert Introductory images of sections

Page 8: Integrated comprehensive school, Frankfurt-Riedberg (DE) 2016, NKBAK Photo: Thomas Mayer Page 64: Woodie Student Hostel in Hamburg (DE) 2017, Sauerbruch Hutton Photo: Jan Bitter Page 106: Transport of a room module for a hotel in Nördlingen (DE) 2018, Kaufmann Zimmerei und Tischlerei Photo: Siegfried Mäser Preface

1

Mikko Auerniitty

Development

1 from: Pawley, Martin: Theorie und Gestaltung im zweiten Maschinenzeitalter. Braunschweig 1998. p. 108 2 Huth, Steffen: Bauen mit Raumzellen. Analyse einer Baumethode. Wiesbaden / Berlin 1975, p. 165 3 from: Detail 1–2 /1970, p. 58 4 from: Raumzellen aus Kunststoffen für einund mehrgeschossige Bauwerke: 1967 Architekten Ralf Schüler und Ursulina Witte, Berlin. In: werk 6/1968, p. 358 5 from: Janser, Andres: Raumzellen für Modul-Holzbausystem. In: Schweizer Ingenieur und Architekt, 13/1996, p. 9 6 Tomio Ohashi 7 from: Pracht, Klaus: Holzbausysteme. Cologne-Braunsfeld 1981, p. 143 8 b ERNE AG Holzbau, Laufenburg

Appendix

9 11 12 13 14 15

merz kley partner Architekturhaus Wiener Strasse, Graz Architekturhaus Wiener Strasse, Graz Berghof Fetz Ignazio Martinez Eva Schönbrunner

Process

2 b Stefan Müller-Naumann 3 Kampa GmbH 4 ARTEC 5 from: Kaufmann, Hermann; Krötsch, Stefan; Winter, Stefan: Atlas Mehrgeschossiger Holzbau. Munich 2017, p. 146 6 Architekturhaus Wiener Strasse, Graz 7 Thomas Mayer 9 b Janez Martincic 17 Tulamo, Tomi-Samuel (ed.) et al.: smartTES. Innovation in timber construction for the modernisation of the building envelope. Munich 2014, p. 6 19 a ERNE AG Holzbau, Laufenburg /  Photo: Marcel Kultscher 19 b ERNE AG Holzbau, Laufenburg /  Photo: Marcel Kultscher 20 Jan Bitter

1 Siegfried Mäser 4 a Erne AG Holzbau, Laufenburg /  Photo: Gataric Fotografie 4 b Erne AG Holzbau 5 Erne AG Holzbau 6 b Siegfried Mäser 7 a Siegfried Mäser 7 b Siegfried Mäser 7 c Siegfried Mäser 7 d Siegfried Mäser 7 e Siegfried Mäser 7 f Siegfried Mäser 7 g Siegfried Mäser 7 h Siegfried Mäser 7 i Siegfried Mäser 7 j Siegfried Mäser 8 according to: proHolz Austria (ed.): Zuschnitt 09/2017, p. 6 and Kaufmann, Hermann; Krötsch, Stefan; Winter, ­Stefan: Atlas Mehrgeschossiger Holzbau. Munich 2017, p. 145 9 Hämmerle Spezialtransporte GmbH 10 Hämmerle Spezialtransporte GmbH 11 a Siegfried Mäser 11 b Siegfried Mäser

Timber Constructions

Project Examples

Design and Typology

2 Kaufmann Bausysteme 4 merz kley partner 5 merz kley partner 7 according to: Kaufmann, Hermann; Krötsch, Stefan; Winter, Stefan: Atlas Mehrgeschossiger Holzbau. Munich 2017, p. 39 8 merz kley partner 9 Kaufmann Bausysteme 10 Kaufmann Bausysteme 18 Kaufmann Bausysteme 19 Kaufmann Bausysteme 20 Kaufmann Bausysteme Layers, Shell and Technology

7 a 7 b 7 c 7 d 8 11 12 15 b 15 c 15 d 17 18 19

Rasmus Norlander Architekturhaus Wiener Strasse, Graz Götz Wrage Mikko Auerniitty RADON photography / Norman Radon Alexander Gempeler RADON photography / Norman Radon Philippe Ruault RADON photography / Norman Radon Thomas Mayer Siegfried Mäser Siegfried Mäser Siegfried Mäser

p. 64 Jan Bitter p. 66 Adolf Bereuter p. 67 above Adolf Bereuter p. 67 centre Adolf Bereuter p. 67 below Kaufmann Zimmerei und Tischlerei; Adolf Bereuter / BMW Group p. 68 centre Kaufmann Zimmerei und Tischlerei; Adolf Bereuter / BMW Group p. 68 below Kaufmann Zimmerei und Tischlerei; Adolf Bereuter / BMW Group p. 69 sitka.kaserer.architekten zt-gmbh (DI Norbert Haiden) p. 70 sitka.kaserer.architekten zt-gmbh (DI Norbert Haiden) p. 71 left sitka.kaserer.architekten zt-gmbh (DI Norbert Haiden) p. 72 below RADON photography / Norman Radon p. 73 above RADON photography / Norman Radon p. 74 Sascha Kletzsch p. 75 Sascha Kletzsch

p. 76 Sascha Kletzsch p. 77 ARTEC p. 78 above left Morten Pedersen, Inviso p. 78 above right Morten Pedersen, Inviso p. 78 below left ARTEC p. 78 below right ARTEC p. 79 ARTEC p. 80 Jan Bitter p. 81 Jan Bitter p. 82 Jan Bitter p. 83 Jan Bitter p. 84 above Archipicture, Dietmar ­Tollerian p. 84 below left Andrew Phelps p. 84 below right Andrew Phelps p. 85 Andrew Phelps p. 86 Mikko Auerniitty p. 87 Mikko Auerniitty p. 88 above Mikko Auerniitty p. 88 below Mikko Auerniitty p. 89 Philippe Ruault p. 90 Philippe Ruault p. 91 above Philippe Ruault p. 91 centre Philippe Ruault p. 91 below Philippe Ruault p. 92 RADON photography / Norman Radon p. 93 RADON photography / Norman Radon p. 94 Olaf Mahlstedt p. 95 above Olaf Mahlstedt p. 95 centre above Olaf Mahlstedt p. 95 centre below Olaf Mahlstedt p. 95 below Olaf Mahlstedt p. 97 above Rasmus Norlander p. 97 Mitte Bauart p. 97 below Bauart p. 98 above Rasmus Norlander p. 98 Mitte Rasmus Norlander p. 100 above Nadja Frey p. 100 below centre  Erne AG Holzbau p. 100 below right Erne AG Holzbau p. 102 Thomas Mayer / thomasmayerarchive.de p. 103 above Thomas Mayer / thomasmayerarchive.de p. 103 centre RADON photography / Norman Radon p. 103 below RADON photography / Norman Radon p. 104 centre Thomas Mayer / thomasmayerarchive.de p. 104 below Thomas Mayer / thomasmayerarchive.de

109

Appendix

Subject Index

Access typology 19ff. Access, linear 20 Access, point-based 20 Addition of floors 14f. Arcades41ff. Architectural quality 25 Atrium20 Automated construction 23

Contracting, public 51, 53 Cooperation models 51ff. Core-access building 20 Cost security 63 Cost-effective building 6 Crane60 Cross-laminated timber 28ff., 37ff. Customisable room module  systems 24f.

B

D

Balconies41ff. Base plate 45 Basement45 Basic prerequisites 62 Beam28f. Beam, wall-like 33 BIM (Building Information   Modeling) 54 Board stack timber 27ff., 37f. Brief62 Building class 37 Building permission 53 Building physics-related   requirements 29, 31 Building services 38, 46f., 62 Building shell 39ff.

Decision aid 62 Decoupling34f. Definitions6 Degree of installation 63 Degree of prefabrication 55 Degree of prefabrication of the   facade 41, 61 Design planning 53 Designing with room modules 16ff. Detail development 35 Development9ff. Development strategies 24 Dividing wall constructions 39 Double shells 6, 62 Driving rain sealing 60

A

E C

CAM joinery and trimming 50, 54 Cams35 Ceiling constructions 37ff. Ceilings29ff. Central-corridor types 18 Cladding40 Clustered flats 21 Columns28f. Combining layers 39f. Communal living 21 Completion61f. Connection of modules 34f. Construction costs 59 Construction method 24 Construction period 63 Construction site logistics 59 Construction system 24, 29ff. Construction, rear-ventilated 45f. Contracting models 51ff. 110

Ecological quality 62 Edge modules 26, 31 Effectivity 9, 62 Emissions63 Encasement 30, 32, 37 Extension of building stock 22f. External wall 39ff.

Foundation Frame construction Framework conditions Framing station Functional tendering

33, 44ff., 59f. 27ff., 39 62 50, 55 52, 63

G

Gantry robot Genius loci Glued-laminated timber

54 24 37f.

H

Hierarchy of load-bearing  structures Horizontal fire protection bulkhead Horizontally lying timber Hotel construction Hybrid room module Hybrid structures

16ff. 47ff. 32 22 6 27

I

Implementation planning 53 Implementation process 51ff. Individual foundations 32f. Individual room module architecture 24 Individuality24 Inserted room module 16ff. Installation areas 49, 62 Integral planning 53 Interface (building services) 48 Interfaces53 Interior construction elements 36 J

Joint 39ff., 44 Joists27

F

Facade39ff. Facade cladding 40 Field factory 38, 74f. Fire protection bulkheading 47ff. Fire resistance duration 32, 37 Fire safety 17, 30, 36, 62 Fire safety requirement 22, 48 Flat roofs 44 Floor29ff. Floor heating 49 Floor structure 36f.

L

Layer structure 36ff., 38ff. Layered models 20f. Lightweight construction 17 Line support 32f. Linear access 20 Load concentrations 33 Load transfer 24f., 31, 62 Load-bearing capacity of   cross-laminated timber 32 Loggias41ff.

Appendix

M

Maintenance   (building services) 49 Manufacture54ff. Manufacturing process 55 Mass-spring principle 38 Maximum dimension 57 Milling work 49 Mobile crane 61 Module ceiling 36f. Module joints 41 Module mounting 60 Module sizes, transportable 57 Module supports 32f. Module units 62 Module wall 39 Modules with lightweight  structures 17 Modules, connections 34f. Modules, inserted 16ff. Mounting 59ff., 63 Multifunctional bridges 55 Multistorey buildings 11ff. N

Non-insulated roof  construction 43 Notches35 Number of modules 62 O

Open skeleton structures Overhaul (building services)

17 49

P

Parameter62 Planning, implementation 53 Planning, integral 53 Point foundation 45f. Point-based access 20 Point-based support 32f. Positioning35 Prefabrication 46f., 53, 63 Prerequisites62 Process50ff. Project development phase 62 Project duration 51 Project schedules 51

Projection42 Public contracting 51, 53 Q

Quality management

55

R

Rear-ventilated construction 45f. Recesses35 Recyclability63 Reinforcing 33f., 36, 62f. Requirements, building physics related 29 Requirements, fire safety 22, 48 Requirements,   sound insulation 22, 29, 31 Roof constructions 43f., 60 Roof drainage 44 Roof shapes 43f. Roofs, sloping 43 Room height 30 Room module architecture, individual 24 Room module construction systems,  customisable 24f. Room module manufacture 50ff. Room module, inserted 16ff. Room modules, auxiliary 20 Room-in-room principle 17 S

Sanitary cubicle 16f. Scaffolds61 Schedule 51, 59 Selection of construction  system 29ff. Serial manufacturing 62 Serving room modules 20 Settling32 Shaft arrangement 46ff. Shaft routing 46f. Skeleton structures, open 17 Sloping roofs 43 Sockets49 Sound insulation 6, 22, 29, 31, 34f., 36ff. Space formation 16ff. Spans29 Special forms 19 Stack effect 41 Statics 29, 31

Strategies23ff. Strip foundations 33, 45f. Styria12ff. Summer thermal insulation 46 Support33 Surface 29, 31, 36, 62 Switch49 Switzerland11f. System combinations 27f. Systems27f. Systems, wood-concrete composite  material 29 T

Tendering51ff. Tendering, functional 52 Thermal insulation, summer 46 Thermal insulation, winter 46 Threshold-free transition 16f. Tightness60 Timber architecture 27ff. Timber structures 26ff. Timber, horizontally lying 31 Transition, threshold-free 16f. Transport 26, 57f., 63 Transport expenditure 58 Transport weight 6 Transportable module sizes 57, 62 Transverse force transfer 35 Types of flat 18 U

Underpinned ceiling 33 Urbanisation6 Utilisation unit 20, 36 V

Ventilation duct Vertical fire protection bulkhead

49 47ff.

W

Wall-like beams 33 Walls 31, 37 Weather resistance 41 Wind-proofing60 Winter thermal insulation 46 Wood-concrete composite  systems 29 111

112

Continuing urbanisation and the growing need for housing demands expeditious construction methods with low emissions. For this reason, architects, investors and politicians are searching for solutions to provide sustainable and flexible housing space in a swift and affordable manner. Classic areas where the modular construction method is used include multi-storey housing, especially student residence complexes, senior citizens’ homes and refugee accommodation but also hotels and hospitals, office and administration buildings or schools. Contemporary examples prove that room module-­ based construction makes possible unexpectedly multifaceted and differentiated architectures. Alongside the known advantages of flexibility and variability, ­timber room modules offer short construction periods thanks to a high degree of prefabrication; a pleasant indoor climate; easy dismantling due to detachable connections as well as high recyclability; and – not to be underestimated – general acceptance by the users. Building in Timber – Room Modules, published as part of the Practice series, provides an overview of the architecture, construction and load-bearing structures of timber room modules, as well as the entire planning process up to assembly. A section with project examples presents architecturally outstanding buildings of various typologies and offers many ideas for one’s own practice.

ISBN 978-3-95553-494-3

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