The building site is a 'remaining' plot within a new development area, the possible public space is a 'remaining area' around the 'remaining area' for construction. Public space must be gained in order to create a qualitative overall solution.

Thus a certain volume is subtracted from the entire volume to add it to public space. A covered exterior space comes into being, which is spanned below the built volume and is covered by that in a different height development. A 'stage' for future issues or just a vibrant urban space is generated.

The building is designed in such a way that the topic 'future' can be extended. Some event and exhibition areas are directly connected to public space, thus additional to its core topics the HdZ can provide 'space' for other currently relevant future issues - also external initiated and used.