About this Book

Wood and stone are the oldest building materials known to mankind. Both are natural products and both were originally certainly used only in their natural form: stones either rounded by the action of water or with sharp edges, wood still in the shape of trunks and branches. While stone is hard, rigid and permanent, wood is soft, warm and, even after felling, still organic. Wood breathes, swells and shrinks throughout its entire life; it is almost as though the felled tree lives on in our boards, planks, beams and columns.

Mythical Beginnings | Trees were regarded as living beings by our prehistoric ancestors. They felt a kinship with the trees who, like them, stood upright. They witnessed their growth, their active response to the changing seasons, their fight for light As well as their death and decomposition, and saw this as an allegory on their own lives. Our ancestors also observed how each year the trees generously bestowed thousands of seeds and fruits on them, how they provided shelter and protection for countless birds and animals, how they were firmly anchored in the ground but flexed defiantly in the wind. In many cultures trees evolved into a symbol of life itself, which found expression in numerous myths and legends. By contrast, modern man and modern woman, with their scientific viewpoint and rational explanations, regard trees as merely functional objects: as suppliers of firewood or building materials, as climate regulators or windbreaks, at best of aesthetic interest to artists or nature-lovers.

History | But even today, when we use wood for building purposes it appears as an almost alive and very complex material. Just the fact of the dissimilar swelling and shrinkage characteristics in different directions and the different strengths along and across the grain, make wood an extremely sensitive building material which needs to be treated carefully by experienced hands. For centuries guilds of carpenters and joiners were the highly esteemed guardians of the knowledge and secrets of woodworking. A building culture which over generations altered only marginally, developed and refined the techniques needed for the optimum use of wood in various structures. The converse was also true: buildings were adapted to meet the possibilities and properties which wood offered; at that time, no designs were put forward which were not "buildable"!

Monument Time Oshima
Benson and Forsyth, "Monument to Time", Oshima, 1992. Exterior view and plan.

Things began to change in the 18th century. After the light-hearted and florid but, in terms of construction, completely non-productive Rococo period, the "Architecture of the Revolution", practised by such architects as Etienne-Louis Boullee (1728-1799), for the first time proposed "unbuildable" designs - structures with huge, geometric forms. At the same time, however, a new building material emerged: iron, both cast and wrought, which for the first time could be produced economically in large quantities. Iron was stronger than all building materials previously known and, furthermore, possessed the agreeable property of being isotropic, a major contrast to wood with its so very different properties dependent on direction. So it is easy to understand how iron - and later concrete and steel - triumphed as a building material. This new material presented just so many more opportunities. The attempt at an aesthetic return to the traditions of the Romantic period, in particular the English Arts and Crafts movement, failed to halt these developments. As methods of analysis and construction improved, methods which of course preferred homogeneous materials, so wood retired from the scene of the innovative engineers and architects. Only in low-tech, low-cost buildings and in romantic imitations did wood survive the unstoppable concrete and steel boom of this century.

Wood lived on too in regions where the economic production and processing of the new materials was not possible, either because of the lack of a qualified workforce or the lack of the necessary division of labour. Several larger countries have tried to solve this problem by force - with dubious success. These were perhaps also regions and cultures in which the social structure was not so geared up for quantitative growth. For whatever reason, in such regions wood was given the chance to gradually adapt to changing living standards and customs.

New Uses | Of course, the rediscovery of wood in the industrial countries has been helped by the growing awareness that our unrestrained plundering of nature cannot continue if we are to preserve those things fundamental to our existence. Materials which can only be produced with enormous amounts of energy and which are difficult to recycle must be reduced to the absolute minimum. Wood suggests itself as an obvious alternative. As it grows - in the form of a tree - it regulates our climate, stabilizes the water content in the soil and in the air, and is the primary element in a balanced biosphere. When a tree dies or timber is disposed of, the wood, through rotting or combustion, is returned to the natural cycle without any additional energy input.

Modern Needs | Wood stands opposed to today's matter-of-fact computerized calculations and aspiring demands. However, we are living in an age in which the disparity between technology and nature is acknowledged, and to tackle this is regarded as a vital task of our time. In Oshima in Japan the London-based architects Benson & Forsyth have erected a structure which symbolizes this current theme magnificently: the "Monument to Time" (1992). Aligned with the Polar Star and intersected by flights of stairs, this building illustrates two different and separate construction principles. On one side are cylinder, cube and pyramid, representing the intellectual approach, on the other side the hand-crafted construction favouring natural materials, in this case Bamboo, that "Oriental" wood. Two worlds, separated and yet neighbours, are united within the circle of rough stones which surrounds the structure and provides its foundation; a new interpretation of theTaoist yin andyang symbol.

Tradition | So how can wood be reasonably and sensibly integrated into our high-tech construction industry? Many fundamental studies and experiments involving wood as a building material are being undertaken throughout the world - many outside the glare of publicity. At Wiesbaden University in Germany for instance, where as part of a special research programme the architect Professor Johannes S. Fritz and his students have erected structures built entirely from stripped tree trunks. Here, investigations are being conducted into the undisturbed strength of the timber and the stability of curved trunks in order to discover new forms of timber construction and hence new architectural approaches. At the same time, the architect Kazuhiro Ishii has built a puppet theatre using solid timber members with the traditional, "impressive" dimensions. He has created a framework of such structural and constructional complexity that it hardly fits into the pattern of modern structural analysis - it could only have 9

evolved out of an old building tradition.

In Hungary a group of dedicated architects is trying to develop or stimulate a native Hungarian style of architecture which uses the indigenous timber in an "organic" manner. They and their vigorous proponent Imre Makovecz are following in the footsteps of the Hungarian architects of Odon Lechner (1845-1914) and Karoly Kos (1883-1977). This group is represented in this book through Dezso Ekler and his structures for the summer-camp in Nagykallo - evidence of the durable impulses for today's architecture provided by traditional and "primitive" forms of timber construction.

Experimental Timber Frame Construction
Johannes S. Fritz, Experimental tree-trunk construction, 1990.

Timber-frame Construction | Throughout the world the American "timber-frame system" has become accepted for smaller building projects such as housing. This system, which only employs standardized members, originated in America and can be traced back to the old pioneering days. This type of construction is astonishingly widespread - albeit in a multitude of variations. Its small-sized sections enable buildings to be easily, simply and quickly erected, and corresponding standardization permits simplified design calculations. Of course, these small sections do increase the fire risk and that must be taken into account, and the low self-weight of such constructions requires special measures in order to maintain acceptable sound insulation. The requirements vary from country to country and from structure to structure, resulting in the most diverse opportunities for this form of construction. As an example I have selected a housing project in Los Angeles designed by the architect John Mutlow. It is not especially spectacular but fulfils all the needs of its occupants.

New Technology | Certain technological developments are aimed at improving the isotropic behaviour of wood. Bonding pieces of timber together cross-wise results in elements which no longer exhibit the "negative" properties of solid timber. These elements do not split or warp and possess uniform properties in tension and compression. On the one hand, these laminated timbers (glulam) or, when thinner laminations are used, veneer laminated wood panels (e.g. "Kerto"), present a degradation of wood and its natural properties. On the other hand, with this reverence to our high-tech requirements we are often able to employ timber to conquer hitherto unattainable realms of construction. In particular, glulam sections enable us to span the great distances often desirable in modern structures and which would otherwise only be possible in steel or reinforced concrete. This book provides a number of examples of this, in the form of sports centres and bridges.

These examples reveal just how important the connections are in such structures. The enormous concentration of loads at the supports, in the joints be-10 tween beams and columns, can no longer be accommodated by the timber alone

- steel components are required to transfer such forces. This book shows quite clearly how various architects working in different countries have tackled this type of detail. The whole range of possibilities is represented, from meticulous, coherent planning by the designer to the delegation of this whole task to the contractor. This observation is not intended as criticism; I believe that in this transitionary period we must experiment with different approaches. A consensus concerning the appropriate integration of details within the overall construction can only be formed gradually - and in terms of timber construction we are really only in the development stage.

Detail and Whole | A detail is a part of the whole. The details of a structure could certainly be studied and analysed for their own sake. However, they are and remain pieces, integral elements within the overall structure. They have their own language, express the spirits of the architects and engineers, reflect local traditions and building skills, indeed even the local climate and social structure. Therefore, in my treatment of the projects described here I have in each case first outlined the aspects specific to that particular structure. The emphasis might be on a special technical requirement, such as in Darwin College in Cambridge with its still-green oak members, or the brine baths in Bad Durrheim where a timber structure is essential owing to the aggressive salt-water vapours, or the combined efforts of amateur builders, like in the Nagykallo summercamp or the McMullen summer-house in Ontario. There are high-tech houses which make use of timber for their primary elements, such as the "Heliotrop" by Rolf Disch. Other architects try to deal with tradition creatively and openly, such as the church designed by Walter von Lom or the aforementioned puppet theatre of Kazuhiro Ishii. So, each and every structure has its own personality which is also reflected in its details. This is why details cannot be judged properly when they are separated from their whole. Climate, local building methods, personal design preferences and a host of other factors all play a role, and it is quite legitimate to regard and to categorize even factors like durability, sound insulation, etc. differently. Every structure is a weighted optimization of all the factors, from the function to the cost, from the skills available to the engineering requirements.

Further, I think that the personality of the designer and the builder are an intrinsic part of a structure. Therefore, where possible I have also included original detail drawings by architects, engineers and contractors in my description. These speak their own language and express something specific about the project and its evolution.

Outlook | Today, the most diverse applications of timber in construction are being tested, offered and implemented. Timber in conjunction with steel, plastics and adhesives is becoming more and more widely accepted. Timber as an organic building material, as a bringer of hope for a more environmentally aware techno logy, would seem to be re-conquering the construction sector to an increasing extent. We find ourselves in the middle of a secular upheaval; this book attempts to record the current state of development by means of a number of examples.

Acknowledgements | Particularly difficult and time-consuming during the preparation of this book proved to be ascertaining and procuring the detail information and drawings as well as the photographs taken during construction, which are often indispensable in clarifying construction systems. In most cases some time had elapsed since the design work was concluded, and the documents had already been sent to the archives or the architects were no longer in possession of the information. My research often led me to the builders and from there to 11

the individual members of staff responsible. I had to rely on the assistance of many others.

Therefore, I should first like to thank all those architects and their assistants who painstakingly provided the answers to my, often, intrusive inquiries and detailed questions. In particular Professor Bernd Steigerwald for the Wilkhahn production plant, Dipl.-lng. Hans Purkarthofer for the tennis halls in Bad Walters-dorf, Iwona Buczkowska for the housing development in Le Blanc Mesnil and the Collège Pierre Sémard in Bobigny, Mikael Uppling for the KTH sports centre, Anna Brunow for the Rausti sauna, Richard J. Dietrich for the bridge in Essing, as well as Flemming Ibsen, Christian Kandzia and Peter Wohrle. On other occasions it was only the engineers or carpenters in the timber construction companies who were able to provide more accurate information, in particular Hans Meier (Wey Elementbau) for the Wohlen High School, Walter Bieler, who designed and built the cross-country ski bridge in Pradella, and Lars Serrander from AB Fristad Bygg.

Serious language problems were encountered in the communications with the Japanese and Malaysi'an architects. Therefore, I am especially grateful to Andrew J. Geddes for his marvellous help with the translations and correspondence, and also to the Japanese architect Toshiya Maeda from the Berlin office of Takamatsu + Lahyani Architects.

Finally, a special word of thanks is due to Ria Stein of Birkhàuser, who read my manuscript and helped me through the difficult initial stages. Tackling and overcoming the problems which arose throughout this project would not have been possible without her constant loyal support and encouragement.

12 2 | Ground floor plan, scale 1:500. The five computer rooms, each with six terminals and small windows overlooking the river, lie alongside the access corridor. Between these, staircases ascend to the reading and study area. To keep out street noise the slightly curved roadside wall runs the whole length of the building. On right: recreation room and access area.

3 | Isometric projection of load-bearing timber construction, scale 1:150. At front and in middle: the fixed points formed by the many twin primary posts, connected by beams at top that cantilever out at sides. These cantilevers carry the suspended intermediate beams.

4 | Isometric projection.

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