It is generally agreed that in the 1920s the "modern" in painting, sculpture, architecture, and many other fields flourished most particularly in France, Germany, and Russia. It is also agreed that during the 1930s further development of the "modern" was crushed in Germany and Russia by the rise of totalitarian dictatorships, that painting, sculpture, and literature reverted to "Realism" and that architecture reverted to the "neo-Classical." There is no space here to discuss the way in which "Realism" and the "neo-Classical" survived in other places where "the modern" had hardly developed (such as the USA) (but see Broadbent 1979). But in Germany there certainly had been by the middle 1920s--thanks largely to the influence of the Bauhaus--a flourishing avant-garde in art and architecture including what, somewhat euphemistically, is called 'social housing" in the form of existenzminimum dwellings with the tiniest of bathrooms and kitchens. In Frankfurt, particularly, under Ernst May, some of these were built with prefabricated systems using wall-size precast concrete slabs.