Antwerp Port House

The brief for the competition, organised by the Flemish government’s architects’ department, stipulated only one requirement: the existing building on the site, a disused fire station on the threshold between the city of Antwerp and its port, was to be preserved. ZHA obliged by proposing a four-storey addition that was hoisted into the airspace above the fire station, rather than sitting next to it and obstructing views of its facades.

The original design for the fire station, completed in 1922, included a spire like that of the 16th-century Hanseatic residence it was modelled on. Although this spire never materialised, it generated the notion of building above the fire station’s hipped roof.

A north-south orientation enables an inclined leg of concrete, and the stair tower which supports it, to straddle the south flank of the fire station, assisted by four inclined shafts of fabricated steel sheet. The slight offset between the axis of the existing courtyard and the addition allows daylight to enter the glass-roofed atrium.

The extension and the upper levels of the fire station serve as headquarters for Port of Antwerp staff. The ground floor, including the courtyard, is open to the public, who can enter through a large portal in the south facade. In the courtyard, inclined columns shoot through a glass roof and tilt at the triangular-scaled underbelly of the diamond ship overhead. The glass roof is supported by a grid of steel flats with complex diagonal trimming members at the column penetrations and tramline patterns around the parallelogram stair shaft.

The floors above reveal more incident and complexity, with layer upon layer of heavy primary structure and secondary framing for the external envelope, stepped ramps like the decks of a galleon, caverns of activity-focused office space in white and grey and the beacons of sulphur yellow-lined cores.