15 Blümlimattweg, Thun
2021
Switzerland’s first apartment building with a wooden basement featuring TS3 joints was constructed at Blümlimattweg 15 in Thun. The building also serves as the living lab for the DeepWood research project and incorporates innovative approaches to building physics.
The Project
An apartment building full of innovations was built in Thun. Concrete was not used anywhere in the entire building, which has five residential units—not even in the basement. Cross-laminated timber panels serve as the floor slab, laid over a 160 mm thick insulation board. The wood is permanently protected from moisture ingress by the “black tank” principle. In the basement, only the exterior walls and individual columns are load-bearing; the interior walls can be arranged freely. This makes the basement highly flexible in use and, thanks to the exposed wood surfaces, provides a pleasant indoor climate.
The house in Thun also serves as the Living Lab for the DeepWood research project in collaboration with the Lucerne University of Applied Sciences and Arts and the Bern University of Applied Sciences. DeepWood is advancing the development of Building Information Modeling (BIM) planning methods
Construction Method
The basement is a solid wood structure made of cross-laminated timber panels. Using TS3 technology, the individual panels were structurally connected to form a large-scale floor slab. The exterior walls of the basement are also constructed of cross-laminated timber. Starting from the ground floor, the apartment building was constructed using a highly insulated wood-frame construction method. This made it possible to eliminate the need for a conventional heating system throughout the entire building.
The Challenges
At Blümlimattweg, TS3 joints with 45° miter joints were cast for the first time in a construction project. TS3 had previously only gained experience with this through research projects. Another challenge of this project was the cold temperatures during casting. To address this, winter construction measures were developed and implemented. The joints were heated locally.
Construction data
- Number of floors: 3
- Gross floor area: 998 m²
- Cross-laminated timber: 178 m³
- TS3 technology: 360 m³
Architecture
HLS Architects, Inc., Zurich
Client
Yamanakako AG, Thun
Timber engineer
Timbatec Timber Engineering Switzerland AG, Zurich
Timber construction
Stuberholz AG, Schüpfen
GU/TU
Stuberholz AG, Schüpfen
Photography
Nils Sandmeier, Biel
Images
Trade press
Basement made of wood? Why not – First Swiss apartment building with a basement made of wood
Schweizer Holzrevue, Issue 4/5 2024 – Thun in the canton of Bern is home to the first apartment building in Switzerland to have a basement made entirely of wood. This revolutionary building was also deliberately built without a heating system. An inspection. (Report in german)
Long live self-sufficiency?
UND Generationentandem, Issue No. 43.2022 – Wood should not be a fuel, because it is probably the most sustainable renewable building material there is. This is what Stefan Zöllig and Regula A. Bircher believe. In an interview, they talk about their convictions and present their «house without heating». (Report in german)
