In the post war construction until the fall of the wall in 1990, about 3 million residential units were built in the former GDR. 27,5 % was constructed using the WBS 70 large panel system. Over one third of the post war building stock is situated in large urban areas like Marzahn (Berlin). Marzahn was built from 1978 on-wards and created almost from scratch until it reached 62.000 housing units shortly after 1990. A redesign has been made for a large building block containing 580 dwellings, situated near the commercial center of Marzahn. The redesign consists of an urban relocation of functions and an adapted traffic plan, but also the complete interior redesign as well as a totally new façade. The interventions are designed as a catalog to be used in transformations of other WBS 70 building blocks.