Extension and Renovation — Kantonsschule Limmattal
The new extensions expand the existing school with an auditorium, sports halls, science classrooms, and a canteen. The new volumes read as “pearls on a string” — similar in form but varied in height — stepping towards the street to define the volumetric closure of the campus while creating a generous outdoor forecourt.
Like the existing buildings, the new structures are structurally legible: their load-bearing logic is expressed directly through the façades. In the hall wing, the stacking of the sports halls and auditorium achieves structural efficiency while minimising the building footprint. The longitudinal wall of the Aula spans from façade to façade, relieving the loads on the hall ceiling and optimising the overall building height.
The auditorium is constructed as a sound-decoupled timber structure within the cast-in-place concrete shell, allowing simultaneous, acoustically independent use of the Aula and sports halls. Profiled concrete walls in the music room provide room-specific acoustic performance.
Spatial identity is defined by the structural system: a prefabricated beam-and-column frame with cast-in-place concrete end walls for lateral bracing, complemented by non-load-bearing partitions. Building services run between the ribs, with the column-free central zone serving as the primary distribution spine.
The renovation of the existing stock closely follows the original material palette — same detailing, materials, quality, and colour — to ensure long-term coherence and sustainable value retention. Former storage rooms in the centre of each wing are converted into group-study rooms; the closed studio stage in the basement is opened as a learning centre; and the canteen is reoriented towards the outdoor landscape.
