Cooperative Building Volta Nord, Baselpreliminary project

As part of the overarching urban development plan for the Volta Nord area, the southern section of the former industrial and commercial Lysbüchel site is gradually being transformed into a residential neighbourhood. The historic urban fabric of the St. Johann district provides the guiding framework for this expansion. The Housing Cooperative Hegenheimerstrasse plans to construct a new building on development site 4.2 that will strengthen the area’s identity and comprise approximately 60 apartments. Positioned along the visual axis of Lothringerstrasse, the larger building volume marks the entrance to the new Volta Nord district and introduces a larger architectural scale. Its location at a key transitional point—adjacent to the future Lothringerplatz—demands a design of particular responsibility and care.

The building takes its typological reference from the Baumgartnerhaus. First conceived in the mid-1920s, the residential buildings developed by “Baumgartner & Hindermann” have become defining features of the St. Johann neighbourhood. These structures are characterised by façades articulated in a classical tectonic order, incorporating neo-baroque elements. The new design reinterprets these distinctive façades, proportions, and articulations in a contemporary manner. The result is a related architectural expression, featuring a pronounced plinth, articulated cornices, and an attic storey in place of the traditional mansard roof. To fulfil its role as an urban connector, the project includes a permeable ground floor. Publicly accessible spaces foster interaction between residents and the surrounding neighbourhood. The openly accessible circulation layout invites engagement and encourages a sense of community among residents. Apartments of varying sizes are distributed across all floors to promote exchange between different living arrangements. On the street-facing side, the façade is built using whitewashed clay brick. Instead of traditional bay windows, it is articulated by vertically framed, cantilevered balconies. Drawing on the historical reference, the building features a deep outer layer towards the courtyard. This open access gallery is understood as the building’s “street,” where informal encounters naturally occur. Fixed seating areas invite people to linger. The steel gallery construction extends upwards into an open rooftop pergola and a trellis system along the west side, allowing the courtyard façade to gradually become overgrown and green over time.

The sustainability goals outlined in the site specific design plan are met through a low-emission construction approach that prioritises natural and recyclable materials. A solid basement structure supports a hybrid structure, built primarily from wood and clay brick. Concrete and steel are used only where necessary, particularly to meet fire safety requirements. The wooden skeleton construction offers high flexibility, allowing apartment layouts to adapt to changing needs over time. Additional connecting rooms enable easy reconfiguration of floor plans. Within the apartments themselves, the so-called Baumgartner room—a space separated by glazed double doors—creates opportunities for a variety of uses.