As Jews, the family immigrated to Germany because of the anti-Semitism growing in Poland and Russia after the failed revolution of 1905 in the Russian Empire.[1]: 294 Klarwein studied architecture at the Technical University of Munich from 1917-1919, but he was not awarded a university degree.[1]: 294 In 1920, he studied with Hans Poelzig in the master's studio for architecture of the Prussian Academy of Arts in Berlin.[1]: 294 In 1921, Klarwein joined the architectural firm of Fritz Höger in Hamburg.[1]: 294 Höger's office grew considerably in these years with increasing work orders, requiring additional personnel.[2] Klarwein's designs were at the time published under Höger's name.[3] Höger said that Klarwein was "one of the very best" employees.[2] Between 1930 and 1933 Klarwein supervised the construction of the brick expressionist Church at Hohenzollernplatz following his designs in Berlin.