Case Study
K118 Building
Details
Location: Winterthur, Switzerland
Design Team: baubüro in situ (Marc Angst, Pascal Hentschel, Benjamin Poignon, Barbara Buser, Eric Honegger
Caccia ai componenti: Nina Hsu, Milena Buchwalder, Geraldine Clausen, Jan Bauer, Laia Meier)
Program: Renovation begins with sourcing and disassembling existing building structures, materials, and components
Year: 2021
Project
In Winterthur, Switzerland, the former Sulzer factory site has been transformed into a beacon of sustainable architecture. The Pension Fund “Stiftung Abendrot“ repurposed the head building of Hall 118 into a creative hub with 12 studios, think tanks, and a laboratory, built on a radical commitment to upcycling and material reuse.
The building’s shimmering red facade, made from reused metal sheeting, hints at the innovative approach behind its construction. Instead of designing first and sourcing materials later, the project reversed the process: it identified salvaged components and then adapted the design accordingly, requiring a flexible and adaptive planning strategy.
The steel skeleton, once part of a distribution centre in Basel, forms the building’s backbone. Key elements such as the exterior staircase, floor slabs, and granite facades were repurposed from the demolished Orion office building in Zurich. The staircase even determined the floor heights, illustrating how reclaimed materials can drive design decisions.
Concrete use was minimal, and limited to structural needs, soundproofing, and fire safety. This approach cut embodied carbon emissions by 60% compared to traditional construction and saved 500 tons of primary materials.
Natural, low-energy materials further enhance sustainability. Straw bales provided waste-free insulation, while local clay plaster ensured a comfortable indoor climate. Reclaimed wood doors and panels added character, emphasizing a “less is more” philosophy.
The red facade and exposed steel structure showcase how reused materials, combined with adaptable solutions, can overcome design challenges. Prefabricated wooden facade elements harmonize with salvaged components, blending past and present.
Economically, K.118 made sustainability viable. Costs aligned with standard construction, but most expenses went to skilled craftsmanship rather than new materials. This labour-intensive process supported the local economy and demonstrated the value of expertise over resource extraction.
K.118 is more than just a building—it’s a blueprint for circular construction. By seeing discarded materials as resources rather than waste, it challenges architectural conventions and proves that sustainability can be both innovative and economically viable.
Bibliography
Re-Use in Construction: A Compendium of Circular Architecture, (eds. E. Stricker, G. Brandi, A. Sonderegger, Baubüro in Situ, M. Angst, B. Buser, M. Massmünster), Park Books, Zurich, 2023;