Let’s Twist! Administration Building for Antwerp Province

The twist in this compact structure with triangular windows makes the building unmistakable. It stands in a park with extensive green space crisscrossed by softly curving footpaths. The design competition required that the largest possible public park be created in the densely built inner-city location. Moreover, a glass pavilion from the 1970s was to be preserved. This is why the new building is constructed like a bridge. Mighty steel trusses between the elevator cores and inside the façades were needed to support this design. The architects did not discover until a later planning phase that it was not economically feasible to preserve the pavilion, so it has been replaced with a delicate new structure. This area accommodates the building’s core functions: a congress centre and the council chamber, which appears as a parabola on the floor plan. The levels above are home to offices for 660 workspaces.

The bridge construction is essential to the appearance of the building, for the trusses determine the triangular shape of the windows which have been installed in the diagonal braces of the truss. These alternate with closed areas of concrete covered with glass mosaics. The look of the triangular grid extends over the entire height of the building; it also makes its twist possible. Starting at the third storey, the floor plans − which become narrower on each ascending storey − make a turn around their northwest corner.

The entire building is of cast-in-place concrete. In order to create the slight curve in the concrete surfaces, the firm executing the work developed a bespoke malleable formwork system. The client wanted the building to make a statement with respect to energy efficiency and spatial quality. Thanks to geothermal energy, photovoltaics and various control systems, the building is energy-neutral.

We feature this project in Detail 10.2021.

Further information:

Landscape architecture: Michel Desvigne Paysagiste
Building physics: Boydens Engineering
Sustainability consulting: Transsolar
Room acoustics, Soundproofing: Marcelo Blasco