German architect and urban planner. He apprenticed with Herman Muthesius and Fritz Schumacher, before holding a number of urban planning positions in Rüstringen, Schöneberg and Berlin. He was deeply interested in the provision of affordable housing and oversaw the construction of some of the most famous housing settlements of the Weimar period, including Hufeisensiedlung and Siemensstadt. The Nazis removed Wagner from his post as head of the Berlin planning department in 1933. He went first to Turkey and then to the United States where he joined Gropius and Breuer at Harvard. Wagner provided some tentative cost computations for Breuer on the Stuyvesant Six project.