In mineralogy, a geode is a roundish cavity bounded by a uniform outer layer of rock. It is formed when the approximately 1,200 °C hot rock of a lava flow envelops gas bubbles and fossilises. In Cologne, an architectural geode was created from cubes encasing an atrium. Here, too, the outer layer is encased in a layer fired at 1,200 °C. However, this was fired from raw clay at Ströher. For Astoc architect Peter Brenner, the most natural variant of his façade requirements: anthracite-coloured clinker brick slips with multiple finishes. It is the first building on the site - but it will not be the last. Following the demolition of railway facilities and the production buildings of a chemical factory, a field of possibilities is emerging on the Deutzer Feld in the Kalk district of Cologne. Kölncubus is making a start in terms of urban development with 4,400 m² of office and catering space. Visible from afar, easy to reach, dome-orientated and with a fantastic view. The DGNB has already honoured Kölncubus as a ‘Green Building’. Perhaps the coveted ‘MIPIM Award’ will follow.