Developments conceived following the principles of Athens Charter were typical form of urban answer to the post-war housing shortage and during the decades of intense construction activity that followed. In city of Belgrade, multifamily housing in open city blocks built between 1961 and 1990 account for about 40% of current housing stock. The current ownership and operation of these housing blocks derive from their socialist legacy: home-owners rights relate only to the buildings, excluding any open spaces, even the ones immediately along the building’s perimeter. On the other hand, heating is supplied by district heating system. Management of open spaces as well as provision of district heating are subordinates to local municipality (the city of Belgrade). Energy efficiency related refurbishment options for these developments that would engage both the home-owners and the public companies may be the key for bringing ever-needed modernization, prolonged lifespan and a sustainable way of using this portion of housing stock. By applying simple architectural measures, energy demand for heating of these buildings can be reduced by 30-78%, which opens a pathway for effective use of renewable energy sources. Unlike solar energy, which can be managed at building level, geothermal energy can be exploited only at the district level due to the ownership rights. The presented research explores the effectiveness of using geo-thermal energy at a district level coupled with systematic approach to building refurbishment, taking the advantage of the repetitive use of the same building design and the formal and practical relations with local authorities.