In Lenzburg, a new timber residential building has been erected in the fastest speed ever in Switzerland.
An innovative and eco-friendly residential building has been realised in just five months in Lenzburg, built based on a collaboration among Renggli AG, the property owner AXA and Bern University of Applied Sciences BFH.
This high-performance construction system adopts a brand new hybrid modular structure, and follows a surprisingly simple principle: all the apartment modules are fully prefabricated by Renggli, the timber construction expert, and equipped with the bathrooms, kitchens, doors, windows and coverings, as well as the full services of building technologies during the manufacturing process in the factory.
Higher buildings thanks to the steel structure
While the modules were being manufactured in the factory, the foundation and the steel structure were built on site in Lenzburg. The ground slab is the same as it is under the conventional multi-storey residential buildings. Different from previous modular constructions, this project uses steel framework as the supporting structure, through which the loads can be efficiently transferred to the foundation. As the modules below no longer needs to support the load above, using this system can build up to eight storeys. Furthermore, the noise is significantly reduced by a sophisticated acoustic solution between the timber modules and the steel structure, thus can meet the soundproof requirements for multi-storey residential buildings.
“This new building system is a step towards Manufacturing 4.0 in the construction industry,” says Roman Hausammann from the Institute for Timber Construction, Structures and Architecture IHTA at BFH, “The complexity was eased by the development of the hybrid construction system and validated by the inspections. Each building element is prefabricated as one complete system component.” So the kitchens are built-in as one piece, all the bathrooms are identical, and the staircases are installed as standard elements.
The prefabricated modules were delivered by low loader trailers from the factory to the site, and then were assembled within a few hours. As the interior work of the modules has been completed, all needs to be done was to insert the modules into the steel framework and connect them with each other, as well as to connect the building services. The staircase and lift core were attached to the building in front.