Around 1,000 m long and 400 m wide, Auschwitz consisted at the time of 22 brick buildings, eight of them two-story. A second story was added to the others in 1943 and eight new blocks were built.Reichsführer-SS Heinrich Himmler, head of the SS, approved the site in April 1940 on the recommendation of SS-Obersturmbannführer Rudolf Höss of the camps inspectorate. Höss oversaw the development of the camp and served as its first commandant.