Addition of another storey to MFH Schäfligraben, Wallisellen

The project
The addition to the existing buildings was made in a light and modern wooden construction. Inside, the wooden ceilings are visible, otherwise the wood remains structurally active. However, hidden and outside is finished with a new clinker facade. This facade is attached to the wooden structure for stabilization. The visible wooden ceiling is made of horizontal glulam. The existing part of the building was extensively renovated. This included the renewal of the facade, renovation of the wet cells and the addition of a lift to the staircase. New, larger balconies in steel, which are anchored back to the existing building and the wooden structure, provide the apartments with more outdoor space.

The construction
The existing buildings were constructed in solid concrete. Consequently, the alterations in the stairwell with the integration of the new elevator also had to be built in reinforced concrete. The extension was built as a timber frame construction with visible glulam ceilings. Externally, the old balconies were replaced by new ones in steel, which were attached to the existing structure and the timber frame. The new clinker facade also had to be back-fastened to the wooden structure.

The challenge
The exterior wall in wood is located in the insulation level and thus offset from the exterior wall of the existing solid construction. This meant that a support had to be created for the wooden exterior walls and at the same time the tolerances of the solid construction had to be accommodated. The support had to be designed in a statically more complex way, since the concrete edge could not absorb the loads.