Werkstadt Zurich Building X
1st prize in competition
The seven-story Building X complements the “Werkstadt” project on the site of the SBB repair workshops in Zurich-Altstetten. The 25 m high office and commercial building measures approximately 68 × 16 m on the upper floors and tapers on the north side of the 1st floor. The basement contains only access cores and technical rooms.
The supporting structure consistently focuses on reuse: used railway tracks form a closely gridded steel skeleton (approx. 4 × 3 m) as main and secondary beams as well as columns. This significantly reduces spans, column loads, and greenhouse gas emissions (max. 5.0 kgCO₂eq/m²EFA/a). A thin layer of in-situ concrete supports high live loads. Supplementary timber beam ceilings in double-height areas allow for flexible rental spaces. Horizontal stabilization is provided by two in-situ concrete cores, which are founded in the Limmat Valley gravel.