The Sponge Square concept deals with the topics of heat reduction through evaporative cooling, rainwater management and pavement qualities. There are different vegetation groups on the site with growth heights from grasses to perennials and mosses. Their composition is based on the structure of a sponge.

The areas are shaded by heat-adapted woody plants. Shading and evaporative cooling ensure a pleasant stay on the area.

The plaza surface consists of climate tiles made of light-coloured concrete. Their high reflectivity heats the surface less than dark coverings. The tiles are also perforated and therefore permeable.

Accordingly, they allow rainwater to drain away into the ground via a drainage layer and block trenches. Via a pipe the water is collected in a reservoir and thus serves for irrigation during dry periods. During heavy rainfall events, the water drainage is supported by an additional drainage layer.