In 1948, 150 young workers and their families decided to build their houses with their own hands and build an ideal city, in order to escape the housing crisis. After three years of work, the "Cité des Castors" sees the light of day in Pessac, in the Bordeaux suburbs. It is the first city of this type in France, self-financed and self-built. Thanks to this initiative and the vote of the financing law on the "labor contribution" in 1949, around forty Beaver estates were created in France until the mid-1950s.