What is the potential of clay construction? What architectural traditions does this building method draw on, and how can it be utilised more effectively in the future? This book by Roger Boltshauser explores the origins of this natural material and its relevance for the future.
Anne Isopp, morgenbau
Pisé. Hybrid Constructions. Traditions and Potential, ed. by Roger Boltshauser mit Mirjam Kupferschmid, Janina Flückiger, Marlène Witry , Triest-Verlag, Zurich 2026, → order now
How should we build in the future? Anyone leafing through Roger Boltshauser’s new book will get a sense of the answer: with clay – and in more ways than one might have thought possible. *Pisé – Hybrid Constructions, Tradition and Potential* highlights the long tradition of earthen construction and demonstrates the architectural potential inherent in combining earth with other materials. It is a book to browse through, to marvel at and to study – a combination that few books manage to deliver as engagingly as this one.
Photo: Philip Heckhausen
A Future Made of Clay
Clay is a fascinating building material. It is hard to understand why it is used so little in construction, even though it is readily available, possesses so many excellent properties and is, moreover, beautiful. Clay construction has suffered a similar fate to timber construction. With the advent of reinforced concrete, interest in the material – and with it, knowledge of it – was lost. Timber construction has long since emerged from its niche status. Clay construction, too, is well on its way to doing the same. And that is precisely the aim of Roger Boltshauser’s book: to bring clay out of its niche status and into the mainstream.
Photo: Philip Heckhausen
From Morocco to Spain
To this end, Roger Bolsthhauser has been researching the history of earthen construction for years. In an earlier book, he had already explored how this building method spread from France into Switzerland. In this book, he now traces the history of earthen construction from Morocco to the Iberian Peninsula and on to Switzerland. Right on the front cover, you’ll find a map showing historical and contemporary buildings in Morocco and Spain, whilst at the back there’s a map of France and Switzerland. One would love to follow Roger Bolsthhauser along the itinerary he outlines in the book, through the Moroccan desert and across Spain. You can really sense the fascination that the building material ‘lehm’ exudes. The word ‘Pisé’ in the book’s title may sound unfamiliar to anyone not from Switzerland. It’s worth noting that ‘Pisé’ is a French term for rammed earth, which is commonly used in Switzerland.
Foto: Philip Heckhausen
A tower made of rammed earth
The book follows three narrative strands that complement one another: learning from historical examples, the further development of existing hybrid building methods, and their application in new, completed projects. Roger Boltshauser, who has been building with clay since his practice’s early years and for whom climate-conscious building is a central concern, is constantly striving to further develop clay construction. It is no coincidence that the oven tower features on the book’s cover. This is a structure that Boltshauser developed together with students and which, thanks to a prestressed clay-and-timber construction, could be built to such an unusually great height. An innovation in clay construction.
Photo: Studio Bolthauser, Léon Bührer, Rico Furter
Between teaching, research and practice
As a professor at the Swiss Federal Institute of Technology Zurich, Boltshauser works with students using rammed earth in numerous design seminars. Here, they experiment and conduct research; at Boltshauser’s practice, this knowledge is then channelled into new building projects. It is from this blend that this book has emerged, which he has co-authored with Mirjam Kupferschmid (a lecturer in Boltshauser’s department), Janina Flückiger (a former member of staff at Boltshauser Architects and an assistant at the department) and Marléne Witry (a former design assistant at Boltshauser, now a professor at Stuttgart University of Applied Sciences). Through images, texts, plans and detailed drawings, the book demonstrates that much is already possible in clay construction, but that much remains to be explored. The kiln tower on the cover, however, shows the direction in which the journey is heading.
Roger Boltshauser with Mirjam Kupferschmid, Janina Flückiger, Marlène Witry (edd.).
Pisé – Hybrid Constructions. Tradition and Potential
Design: Maike Hamacher, Zurich
480 pages, ca. 630 illustrations,
22 × 30 cm
Triest-Verlag, Zurich 2026
ISBN 9783038630968
