Addition of storey Erikastrasse 11, Zürich

The project
The four-story building is located in Zurich's District 3. In the course of the renovation, the building was raised, the remaining floors and the building services were renewed. Timbatec was responsible for the structural analysis and design of the timber construction, the solid structural analysis and the fire protection (QSS2 due to encapsulated components). The earthquake safety of the building was also assessed by Timbatec.

The construction
The existing building was erected in 1946 as a solid construction (concrete ceilings, exterior and interior masonry walls, stiffening concrete frame construction). The extension was realized in prefabricated timber frame construction. Due to the considerable span as well as the kink in the roof shape, the ribs of the northern roof side were cut out of Kerto panels. The 11-meter spanned ridge beam was realized with over-height glulam.

The challenge
In the project, it was necessary to find an economical supporting structure for the roof, with which the kink in the roof shape could be realized. For this purpose, the girder ribs were form-fabricated from Kerto plates, which eliminated the need for complex moment connections.