After World War I Guimard found it difficult to associate himself with the new Rationalism, even though his housing projects were based on a standardized system of dry concrete block construction and prefabricated elements. The apartment block (1925) at 18 Rue Henri Heine, Paris, his best post-war work, became his own last home in Paris. He appears to have built nothing after 1929 and in 1939 he and his wife moved to New York. (Source: Grove Art Online; http://www.groveart.com/)