This study examines the links between four organizational features of private housing for older persons (service level, perception of environmental control level, tolerance level of caregivers toward seniors and their input in decision making) and the social integration of seniors. This last variable is assessed according to four indicators: presence or absence of meaningful relationships, satisfaction with social life, feeling of loneliness and number of contacts with neighbours. The results obtained by analysing the logistic or ordinal regression and the odd ratio associate two of the four organizational variables studied to most of the social integration indicators irrespective of the subjects' vulnerability level. The two features are service level and perception of environmental control level.