The Kalk Karree development is on the site of an old, disused industrial area. The main user is Cologne city council with its variouse departments and archives. The overall structure is a block construction that mirrors the geometry of the site. In accordance with its use, this building is split into two structures connected by an atrium that is flooded with light. The main entrance façade is made of glass and comprises 96 photovoltaicunits used to generate energy. The architects were sensitive to the history of the location, allowing them to revive the matirials of the old industrial architecture in combination with modern components such as glass façades.