The existing building from the 1950s was extended in three construction phases by five classrooms, two leisure classes with associated group rooms, a gym, a gymnastics hall as well as an administration area while maintaining normal school operations throughout the entire construction period. The existing gym was converted into a dining hall which can also be used as a multipurpose room for all sorts of events.

The extension complements the existing building to form a square enclosing a large protected schoolyard. Access to the school is provided by the new building wing in the north, which accommodates on its ground floor the school administration and the central cloakroom and, on the courtyard side, the library as well as leisure rooms. Above these the building accommodates the new two-storey sports hall as well as the gymnastics hall are located, which cantilevers over the forecourt at the entrance. This arrangement provides a ring-shaped access on the ground floor, which connects the existing and the new building wings in a clear and barrier-free way.

The façade of the two and, respectively, three-storey extension, which is predominantly constructed in timber, is structured in a multifaceted way with horizontally and vertically arranged spruce wood lamellas and large bands of window. A photovoltaic system was installed on the greened flat roof, which contributes to a pleasant microclimate.