A gra­duate of the Uni­ver­sity of Ber­lin, his early stu­dies gave him an in­ti­mate know­ledge of city plan­ning and the his­tory of ar­chi­tec­ture. He first came to the United Sta­tes in 1905 to fill an ap­point­ment as hou­sing in­spec­tor in Phil­adel­phia. In 1909 he di­rec­ted the first city plan­ning ex­hi­bi­tion in Bos­ton and the year fol­lo­wing di­rec­ted si­mi­lar ex­hi­bi­ti­ons in Eu­ro­pean cen­ters. He re­tur­ned to Ame­rica in 1913 and for two years un­der­took hou­sing stu­dies for a num­ber of ci­ties. In 1921 he left Ame­rica to tra­vel ex­ten­si­vely. Fol­lo­wing an in­ter­val of achie­ve­ment in many lo­ca­li­ties, he re­tur­ned to New York in 1933 and was ap­poin­ted Vi­sit­ing Pro­fes­sor of Hou­sing at the New School of So­cial Re­se­arch. In 1935 he be­came an as­so­ciate in ar­chi­tec­ture at Co­lum­bia Uni­ver­sity. His wri­tings in­clude se­veral vo­lu­mes and nu­merous mo­no­graphs on ar­chi­tec­ture and city plan­ning.