With Kunstmuseum Basel’s new building, a prominent location in inner-city Basel has been reclaimed. The extended museum comprises two directly interrelating buildings on opposite sides of the street.
Beneath the street, the link between the main building and the new building is not an underpass, but an extensive spatial structure with span widths of around 10 m across two underground levels that extend down to 12.5 m below ground.

The extension’s excavation pit had vertical shoring on all sides. Depending on the requirements, the edge of the excavation pit was constructed as either a pile wall or an underpinning wall, both of which were temporarily anchored from behind, beneath the streets and neighbouring buildings. The close proximity of the tram tracks necessitated a monitoring concept, and various utility lines in the streets had to be taken into account during anchoring work.