In an interdisciplinary study we analyzed in 800 family dwell ings in Zurich the congruence between architectural structures and the needs of the occupants.For that purpose, we recorded on the one side the architectural structures and on the other side, the social and economical situation of the dwellers. The question, how much space dwellers could actively appropri ate or how much they are influenced by the given architectural environment, has been analyzed in a detailed study of housing and leisure activities utilization of rooms end attitudes toward the built environment taking into consideration the environmental conditions.