School building extension Gallenbühl, Aeugst am Albis ZH

The project
With the addition of the second floor, the school building received a new upper floor. For this purpose, the existing roof was converted into a floor slab, and the new floor is now located above it. The intercepting beams were installed in the old roof because the floor plans on the new floor are different from those on the existing floors below. The joists and ribs in the stud walls and roofs were optimized. The interception of the different cross-sections compensated for the differential deformation.

The construction
The extension was built in timber construction. The ceilings and the roof structure were executed with box girder elements, the walls with stud structures.

The challenge
The long spans of the roof and the ceilings as well as the differential deformation of the interception beams were the exciting challenges for the engineers.