Kraanspoor is a three-storey light-weight office building superimposed on a concrete crane way built in 1952 on the grounds of the former NDSM shipyard, a relic of Amsterdam’s shipping industry. The design challenge was to realise a maximum surface area without making radical adjustments to the 270-metre-long structure, utilising its maximum allowable load-carrying capacity. Fully respecting its foundation, the new construction follows the entire length and width of the crane way, and supported by three-meter-high slender steel columns, it appears to float above.

While the transparent double-skin climate facade permits natural ventilation and acts as a thermal buffer, water from the IJ River is pumped up and used for hydrothermal heating as well as cooling. The four double portal frames function once again as stairwells and a separate prefabricated steel structure, specifically developed for this project, includes new stairs and a panoramic lift. The original concrete structure houses the archive/storage space as well as the building services.