BOB361 Architects has redeveloped Portier 51, a former city library in Mechelen, Belgium.

Portier 51 concerns the redevelopment of the former city library of the city of Mechelen into housing, neighbourhood-supporting and commercial functions, with a new green public and collective garden, a rooftop garden and an underground parking garage, within a historic urban context.

Specifically crucial within the project is its sustainable design and attention to the existing urban fabric.

For the redevelopment of the city library, the City of Mechelen set the bar high by explicitly emphasising circular construction as a key requirement in the competition process.

Central to the project was the question of how architectural interventions can reimagine and revitalise a dense urban block in the heart of Mechelen, while being a frontrunner in sustainable design.

Through subtle and strategic interventions, light and air are drawn into the urban block, making it more open, livable and connected – reshaping the city at multiple levels.

This project has been longlisted in the sustainable renovation category of Dezeen Awards 2025.

Studio: BOB361 Architects
Project: Portier 51
Credits: ARA, Raco, Vibe and Dexco