Additions Nussbaumstrasse, Zurich

The project
In a central location in Zurich's Kreis 3 district, the existing residential building at Nussbaumstrasse 18 is undergoing comprehensive renovation and will be extended with two additional attic floors in timber construction. The extension will create new, contemporary living space, while the floor plans on the existing floors will be adapted to meet today's requirements. The new gable roof connects to the existing hipped roofs of the neighboring buildings and blends harmoniously into the urban environment.

The construction method
The floor of the extension consists of horizontal glulam elements spanned between steel beams, through which the loads are transferred directly into the existing structure. The elevator shaft was constructed as a prefabricated, enclosed CLT shaft and placed in one piece on top of the existing concrete core. The roof was constructed using prefabricated elements.

The challenge
The existing hipped roofs had to be extended to form continuous gabled roofs. The transitions were particularly challenging, as the connections to the fire walls had to be precisely executed and the fire barrier secured.