Like no other architectural task, collective housing is inextricably related to 20^th century social trends – the turmoil of violent war as well as revolutionary or evolutionary changes in social systems. The heroes of modernism have put their best capabilities into social housing with faith in the ability of man and society to be changed by architecture. Both dominant social systems produced an enormous amount of collective residential buildings, entire cities which were mostly a failure in the sense of meeting the requirements set by the pioneers of modernism. This failure had its climax in the famous razing of an entire housing block in St Louis in 1972. The literature on this incredibly complex, but nevertheless important issue could fill up a whole library.