About Lehmag

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A construction company for sustainable building from the excavated material clay.

Clay is a largely unused resource for building in Switzerland and Europe. Every year, the construction sector produces several million tonnes of excavated material, which is directly deposited as landfill. Other resources such as sand are becoming scarce or require a great deal of energy in their production. Based on an extensive building tradition (also in Europe) with the potential building material clay, LEHMAG would like to bring this resource back into the consciousness of contemporary building.

LEHMAG can draw on its broad experience in various areas of building with this material. Together with architects and clients or in a team with competent specialist planners, holistic solutions can be developed from the design phase of a project. The execution of all projects is carried out on schedule with high quality and aesthetics. Innovation and research with the material is essential to advance earthen building and is therefore an integral part of LEHMAG AG.


Felix Hilgert
MSc. ETH Building.

Engineering, planning support, organization

During his civil engineering studies at ETH Zurich, Felix worked intensively with clay as a building material and wrote his master's thesis "Excavated material as the new building material resource for Zurich". After completing his studies, Felix was employed by Roger Boltshauser (Boltshauser Architekten AG), where he gained practical experience in planning and project organization and was able to further deepen his knowledge of clay. He became Roger Boltshauser's research assistant at the Department of Architecture at the ETH Zurich, where he also regularly plans and implements designs using clay as a resource.


Lukas Baumann

Project management, construction management, material knowledge

After 20 years of experience in the building industry as a bricklayer, Lukas Lehm Ton Erde Baukunst GmbH joined the company and played a major role in the Ricola project (herb storage made of rammed earth, Herzog & de Meuron). During this time he was able to gain intensive experience of how large-scale earthen building projects are implemented and acquire a broad knowledge and feel for the raw material. This led him to start his own business as a clay builder. He realized several projects in Switzerland (e.g. multi-storey staircase made of rammed earth in Alpnach) but also in South America (educational institution in Cusco, Peru).

Lukas Baumann attended the training courses in 2019 Historical solid loam construction and Earthen building for architects and engineers of the Bauhaus Academy of Further Education Weimar e.V.

Fountain workshop

The LEHMAG production hall is located in a former cement plant in Brunnen. Here, materials are examined and prepared, components are pre-produced, material samples are produced and discussed with customers and workshops are organised.

Industrial road 7
6440 Wells
41 41 545 94 60


In close cooperation with ETH Zurich and Roger Boltshauser, as well as other universities and lecturers, the LEHMAG regularly organises workshops for students. Participants can get to know clay as a building material in practice, experience the construction and implementation of a building site and gain a better understanding of the interaction between architecture and the use of resources.

For the LEHMAG the transfer and development of knowledge about earthen building is a central concern. Please contact us if you would like to participate in a workshop or organise one with us.


Publication "Pisé - Tradition and Potential".

Felix Hilgert has collaborated and written, among other things, on the publication "Pisé - Tradition and Potential" by Roger Boltshauser, which will appear in spring 2019. ISBN 978-3-03863-027-2 Available from Trieste Publishing House

Article g plus "From the floor into the wall"

Christoph Wegelin has contributed to the topic "From the floor into the wall".


Atelier Switzer
Basler & Hofmann
Boltshauser Architects AG
ETH Zurich, Chair for Sustainable Building, Prof. Guillaume Habert
Garden Poet Ltd
IG Lehm
Ilg & Santer architects
Clay Earth Architecture GmbH
Clay works
Philip Heckhausen
Kurmann & Partner Naturnah Bauen GMBH
Sandro Livio Straube
Selective Studio Ltd

Together with TERRABLOC we produce adobe bricks in the German-speaking part of Switzerland.