The school at Castelligasse 9 is being sensitively renovated and thoughtfully extended with modern, functional elements. Our design respects the character of the existing building while introducing considered architectural interventions – most notably in the central courtyard-facing zone and in the new structure built over the existing car park. The result is a harmonious dialogue between old and new that enhances the site without compromising its identity. The energy retrofit encompasses a highly insulated building envelope and new windows. Parapets are partially removed and replaced by planting troughs with façade-integrated greenery – an ecological design element that improves the local microclimate and lends the building a welcoming, organic character.

The extension makes a deliberate contemporary statement: cantilevering, landscaped balcony slabs, generous window openings, and an elegant Eternit façade create a compelling contrast to the historic punched-window elevation. Greened party walls visually unite the existing and new structures. Functionally, the school is organized into two independent sections – the primary school and the school for inclusive education – each with its own fully accessible entrance. Shared spaces are located in the central wing and on the top floor. Every cluster is provided with its own outdoor space in the form of balconies or terraces. The rooftop is further activated as a usable outdoor space, complete with pergolas and photovoltaic modules. A valuable existing tree in the inner courtyard is preserved through a carefully adapted building footprint.

Sustainability and efficiency are equally central to the structural approach: low-carbon reinforced concrete is used in the basement and ground floor, while the upper floors consist of prefabricated timber elements. A high degree of prefabrication reduces noise, construction time, and emissions – enabling a particularly considerate method of building within a densely developed urban context.