Close to Zurich’s central station the underground extension to an 1898 building is carefully embedded in a lively courtyard.

A generous room in the existing building sounds the prelude to a sequence of spaces. The entry point is through the courtyard. An internal opening links the existing structure and the new underground one. This stairwell, which offers a blank canvas for a variety of uses, leads down into the soberly finished basement space. This connecting staircase is realised in raw concrete; each intermediate landing leads to a wooden niche. The niches each fulfil a distinct purpose, such as providing a reading area or a small kitchen. Contrasting materialisation contributes to the spatial ambiance.

The exhibition space below ground is designed in robust concrete and possesses simple formality. Its size is determined purely by its function and the conditions set by planning regulations; the resulting height and breadth are thus a given of the place. The room is illuminated evenly from above with an inner lightwell in addition. This lightwell forms a key element of the space, including a goods lift that defines its character; as an accessible sunken courtyard, this can equally be employed as an extension of the exhibition space.