Introduction of 4th generation district heating (4GDH) concept is an enormous challenge for district heating (DH) companies in Latvia, since most of the DH systems currently operate at high temperature regime. Therefore, this work analyses the possibility to lower the temperature regime of DH network in existing built-up areas. All stages of the DH system were included in the developed model – heat source, distribution networks and final consumer. The evaluation of various scenarios is done using energy efficiency, technological and financial indicators. Results show that switching to a lower temperature regime can reduce distribution costs and increase overall heat production efficiency. Therefore, in the situation when heat energy consumption in the existing buildings decreases, the current DH system (with high temperature regime) becomes inefficient, where specific distribution costs increases by more than 50 %. This work concludes that 4GDH concept has a high potential in the future, because the implementation of this concept is closely related to the energy performance of buildings.