Conversion and extension at Eidmattstrasse 14, Zürich

The project
The existing apartments were renovated and the wet rooms and riser zones were renewed. Two storeys were added to the existing building. In order to keep the additional loads of the extension as low as possible, it was built in timber construction. Additional steel crosses and concrete slabs were installed on the first floor and basement to strengthen the building against earthquakes.

The construction method
The extension is constructed entirely in timber. The extension of the stairwell and the elevator shaft was constructed with encapsulated CLT walls. Due to the room geometry, the ceilings were made of cross-laminated timber panels. A steel support grid was laid on the existing reinforced concrete ceiling to transfer the loads locally to the load-bearing walls on the floor below.

The challenge
Due to the different floor plans between the extension and the existing building, loads had to be absorbed and transferred at certain points. The encapsulation of the wooden elements of the staircase was carried out cleanly in close cooperation with the timber constructor.