We have won the workshop process for the redesign of the former Karstadt site in Bielefeld’s city center. The Greven-based Sahle Group acquired the 8,815 m² site two years after the store closed and initiated the competition.
We activate. Programmatically, through a mixed-use concept: retail, gastronomy and hotel functions on the ground floor, with hotel, serviced apartments and senior living above as quieter uses. In urban design terms, we activate primarily by deliberately breaking down the new building mass into clearly legible volumes—an ensemble instead of a monolith. Joints, setbacks and differentiated building widths translate the scale of the project into one appropriate for the city center.
Along each of the three street fronts, a clear urban edge is created, each with a distinct orientation and identity. As Bielefeld’s Head of Building and Economic Affairs, Claudia Koch, puts it: “There is practically no backside. Every facade is of very high quality and distinct from the others.”
Bahnhofstrasse is strengthened as the main shopping axis through active ground-floor uses. Arndtstraße becomes an urban transition space with a strong public presence, while the quieter Friedenstrasse is shaped by residential uses. A neighborhood square at the corner of Bahnhofstrasse/Arndtstrasse forms the central public space of the ensemble.
Inside the block, previously undefined residual areas are transformed into calm, clearly defined and landscaped courtyards. Roofs are activated as usable open spaces, while others accommodate PV systems. The facade system reflects the idea of “activation through calming” in its own way: it creates an overall coherence while differentiating the individual buildings through variations in materials and detailing. The buildings at the Bahnhofstrasse/Arndtstrasse corner feature a sand-coloured natural stone and shell limestone facade, appropriate to their prominent urban position. In contrast, the residential buildings along Friedenstrasse are clad in brick, responding to the finer-grained, quieter context.
Structurally, the project is based on a flexible skeleton frame with a regular column grid. Together with the clear separation of structure and fit-out, this is essential for enabling adaptable reuse and long-term viability. The system allows for different uses within a unified framework and ensures lasting flexibility.
The construction also follows principles of resource efficiency: spans are optimized, and materials are used sparingly and in low-CO₂ forms wherever possible. An integrated “low-tech+” approach further leverages the building’s physical properties to minimise energy demand.
Client: Sahle Baubetreuungsgesellschaft mbH
Visualizations: caspar./moka-studio
Landscape architecture: studio grüngrau GmbH
Technical building equipment: DES GmbH
Fire protection: Corall Ingenieure GmbH
Structural engineering: Werner Sobek AG
