Extension to the Allmend school complex, Oberengstringen

The project
The existing Allmend school building, built in 1969/1970, had not met the requirements of today's teaching methods for some time. Due to the lack of special rooms, the school repeatedly reached its limits. For this reason, those responsible in the Zurich suburban community, which borders directly on Zurich's city districts 9 and 10, had a three-story extension built. The cubic new building, with a footprint of 25 by 25 meters, has three floors and is designed in such a way that one floor can be added later. In addition to five classrooms and group rooms each, the new building houses, among other things, a lounge with a small kitchen, a conference room and two offices. Each floor is directly connected to the existing school building via a connecting structure.

The construction method
The school annex was built using a hybrid construction method. Interior walls and ceilings were built in solid construction, the facade is made of wood and is load-bearing. The façade elements were prefabricated and used as supports and stop ends for the concrete slabs during construction. This had the advantage that the timber construction dictated the geometry and thus tolerances and sealing problems between the timber construction and the concrete were not an issue. Consequently, there was no need to match the timber elements to the concrete structure and make them as tight as possible. Rather: With the chosen approach, the concrete adapted to the wood. This meant that the shell construction time was shorter than with a purely solid construction, and the interior work could be started earlier.