Gropius was one of several refugee German architects who provided information to confirm the typical construction of German houses to the RE8 research department set up by the British Air Ministry. This was used to improve the effectiveness of air raids on German cities by the Bomber Command of the Royal Air Force in World War II. The research was to discover the most efficient way of setting fire to houses with incendiary bombs during bombing raids. The findings were used in planning raids such as the bombing of Hamburg in July 1943.