This paper proposes a two-stage approach to choose the priority municipal units for implementing required energy efficiency measures in a district heating system. On the first stage the existing state of district heating system of Irkutsk region (Eastern Siberia) was analysed. On the second stage the choice of municipal units is considered as the Multiple Criteria Decision Analysis (MCDA) problem. The authors selected the most valuable criteria such as tariffs, subsidies and etc. that are rather sensitive for consumers and budget. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) was applied to identify the priority municipal units for implementing energy efficiency measures.