A main reason for problems with property units in close connection within multi-owned buildings is ineffective management and maintenance of these buildings. The article aims to address legal problems related to proper management and maintenance of common ownership property within multi-owned housing. Case studies were conducted in two types of countries: 1) sustainable and diverse system of condominium and long-term management experience of multi-owned buildings (Sweden, the Netherlands); 2) relatively recent system of condominium and developing system of management of multi-owned buildings (Bulgaria, Armenia). A comparative analysis was made with a special focus on common ownership right. The results show that there are various ways of defining common property and arranging the management and several obstacles preventing successful management and maintenance of multi-owned buildings, especially in post socialist countries. A well-designed legal framework is required in order to provide functional management and maintenance of the commons.