This investigation analyses social relations in three different neighbourhoods in Recife-Brazil: a favela, a public housing estate and a middle-class neighbourhood. The investigation was structured by means of Facet theory and the result analysed using the Smallest Space Analyses. It presents projections on the Level of Interaction, the Referent of Action and the Associates. The results show that casual interactions between neighbours form, paradoxically, one of the most important social relationships in the favela, and that questions of space play a determining role in the establishment of these social relationships. The middle-class arena for entertainment and the kind of interaction which takes place in the home is determined by the social role of the associates. Public housing dwellers present a stricter pattern of social interactions not directly influenced by other facets. Results demonstrate that these groups conceptualize and use residential space differently. Urban planning proposals aimed at favelas should consider that changes in spatial organization will also imply changes in social relations and life style.