Conversion Coop City St. Annahof, Zürich

The project
The ceiling structures of the upper two floors had to be inspected in a condition analysis. The analysis also included the attic floor including the two valley beam layers. This revealed deficiencies in the area of fire protection. This resulted in a retrofit concept for the use of the warehouse. The stairwells of the two uppermost floors were also closed off. The stairwell sections were encapsulated. During the entire construction period, it was possible to continue shopping on the lower floors.

The construction
The top floor was reinforced with a strong belt floor. Rock wool panels and gypsum fiberboards were used for the second uppermost floor. The node of the supporting structure, clamps, posts, stirrups, purlins were made fire resistant. CLT panels with encapsulation were used for the staircase.

The challenge
The Coop City department store is located in the center of the city of Zurich. Logistics were therefore a decisive factor in the choice of construction. All components were dimensioned so that everything could be assembled by hand. For crane hoists, delivery had to take place at night. In addition, the facade lift only had a maximum length of 2 meters.