High-performance hybrid construction system made of wood

Together with Renggli AG, AXA and other business partners, BFH has developed a high-performance hybrid construction system made of wood and steel that can be used to build 4 to 8-storey multiple family dwellings quickly and cost-effectively. The apartments are completely prefabricated: Bathrooms, kitchens, doors, windows and floors are installed in the workshop. The first replacement construction with 20 rental apartments has been completed in Lenzburg in just five months.

Factsheet

  • Department Architecture, wood and civil engineering
  • Research focus Institut für Holzbau, Tragwerke und Architektur
  • Research field Holzbau
  • Funding body Innosuisse
  • Duration (planned) 01.09.2017 - 31.03.2019
  • Project management Andreas Müller
  • Head of project Roman Hausammann
  • Project partners - business Renggli AG
    AXA
    H. Wetter AG
    Amstein & Walthert Bern AG
    Geberit Vertriebs AG
    Schindler Aufzüg AG

Convincingly simple high-performance hybrid construction system

The apartments were completely prefabricated as room modules at Renggli AG in Schötz, a company specialising in timber construction. The bathrooms, kitchens, doors, windows and coverings have already been installed, and the building services engineering wires have been put in.

Parallel to the production of the modules, the basement and the steel structure were built in Lenzburg. The basement does not differ from a conventional multiple family dwelling. In contrast to previous modular structures, however, a steel scaffold is used as the supporting structure in Lenzburg. This makes higher buildings possible because the modules are not additionally loaded from above. The prefabricated modules only have to be inserted into the steel frame, connected to each other and the building services engineering connected.

Cheap living space is retained

This hybrid construction system was developed as part of an Innosuisse innovation project and drastically shortens the construction time: Around nine months of construction time was saved on the Lenzburg project. Long void periods and housing shortages can thus be reduced. In addition, the prefabrication and standardisation of the apartments reduce costs – rental apartments where renovation is no longer worthwhile can thus be replaced by inexpensive and modern living space.

Low rents and Minergie-A standard

The house is heated with renewable heat from the geothermal heat pump.
The photovoltaic system produces electricity for the Zusammenschluss zum Eigenverbrauch (consortium for own consumption - ZEV). Three types of apartment were built, two different 2.5-room apartments and one 3.5-room apartment. The apartments have an ecological fit-out standard, modern floor plans, are barrier-free and are let in the low price segment. A 3.5-room apartment, for example, is available from CHF 1420.