Invited by Signa Group, the competition is about re-using the materials which will remain with the conversion of the existing Karstadt department store on Hermannplatz by David Chipperfield Architects. Concular has mapped the available components into a detailed materials-catalogue. The new office building is grouped around three courtyards with 20,000m² of usable space and will be constructed out of timber, unmixed and pollutant-free so that the material can be later returned to the cycle in a non-destructive, dismantling manner. This creates a stock of materials for the future. The materials which are now available, such as travertine, glass, perforated metal sheets and concrete blocks will be mainly used for the facades of the new buildings. The existing 4,000m² glass façade elements will be used for glazing the ground floor zones and the double façade on Urbanstraße. This means that the re-use concept can already be read from the outside through the façade design. A stone band out of travertine also peeps out into the urban space and meanders playfully on the wall and floor through the three courtyards. The material is robbed of its monumentality as it functions as a connecting element, loge, balcony and planter with a historical reference. The existing concrete slabs are reworked in color and laid out again in all courtyards. The greening of the courtyards is primarily provided by green screens, which are intended to grip onto former façade elements. These are also used on the back of the Karstadt façade, like a green waterfall connecting the roof garden of the Karstadt to the new courtyards.