School extension Krämeracker Uster: New buildings made of exposed concrete, terracotta and glass bricks

Uster Primary School needed a new school building and a sports hall in order to accommodate rising numbers of pupils and to allow Uster to grow from an educational point of view. The two new buildings will instantly increase the available school space in Uster by 20 percent.

Expertise involved

Acoustics and noise protection, Building physics, Fire protection, Structural engineering

Client

Boltshauser Architekten, Zurich

Using the biggest pneumatic crane in Switzerland

The architecture of the new buildings is based on the aesthetics of the exposed concrete surfaces, which are combined with terracotta and glass bricks. Basler & Hofmann has translated the challenging architectural concept, which has tough requirements in terms of the quality of the exposed concrete, into a functional load-bearing structure. One particular challenge was the roof construction of the sports hall. 16 pre-fabricated reinforced concrete beams, each with a length of 29 metres, form the load-bearing structure of the ceiling. On top of this are interconnected element panels with a delicate and elegant finish. The unusual nature of this concept was matched by the installation of the ceiling: each of the concrete beams weighing 39 tonnes was placed using the biggest pneumatic crane in Switzerland.

Three-layer sealing concept for the sports hall floor

The relatively high groundwater level also required a number of special measures to be taken, as the large ground slab of the sports hall needed to be secured with micro piles against lifting forces. A floating sports hall floor places particularly challenging requirements on the leak-tightness of the ground slab. For this reason, the construction with waterproof concrete was supplemented inside and out with a plastic seal.

Our services

Project planning for the excavation and foundations. Planning of the works, cables and pipes development. Joint planning of the load-bearing structures. Consultancy on fire safety engineering, building physics and acoustics, including thermodynamic simulation of the building for heat insulation during the summer months for optimised integration in the overall architectural concept.