Sculptural Atrium and Stairway Crafted From Curved CLT in Switzerland

The headquarters of the construction company Blumer Lehmann in Gossau, Switzerland, illustrates the possibilities of contemporary timber architecture, according to a feature by designbloom (3-26-25).

Designed by K&L Architekten, the building’s defining feature is the sculptural atrium crafted from curved cross-laminated timber. Developed by the Institute for Computational Design and Construction (ICD) at the University of Stuttgart, this freeform structure integrates a spiraling staircase that mediates between levels.

The collaboration between the Stuttgart-based team at ICD and timber construction specialist Blumer Lehmann builds upon extensive research into curved timber structures. The stairway of the atrium is integrated within the timber composition, guiding movement while creating balconies and alcoves. The structural efficiency is optimized through the use of two distinct radii for the curved timber elements and repetitive stair modules, ensuring material economy and precision in fabrication.