Sonnenhof is a mixed use co-operative housing project and consists of four new buildings with residential spaces, offices, the headquarter and bank of the housing co-operative Carl-Zeiss-Jena as well as retail and gastronomy. Located on a consolidated number of smaller lots in the historical center of Jena, Germany, the separate structures allow for free access through and urban pedestrian flow through the grounds. Their placement on the outer edges of the plot defines a small-scale outdoor plaza congruent with the medieval city structure. Its outdoor facilities continue the building’s overall design concept past the edges of the lot. The planned incorporation of commerce, residence, and office enables a flexible pattern of use that also integrates itself conceptually into the historic surroundings.