The Directive 2012/27/EU of the European Parliament and of the Council on Energy Efficiency sets the obligation of installing individual metering in all energy systems in all Member States, district heating being one of the systems this obligation applies. The Republic of Croatia has transposed this obligation in the national legal framework in The Law on Heat Market (Official Gazette 80/13, 14/14, 76/18). The main purpose of this regulation is to enable that every consumer pays only for the energy cost that have occurred due to the usage of their property. In the course of 2016, mainly in the first months of the year, a wide public debate was held in Croatia on the cost effectiveness of the introduction of the obligation for the instalment of individual metering in the district heating systems, in particular – the instalment of heat cost allocators. The Cost Benefit Analysis, which is presented in this paper, was performed in line with EU guidelines published in the Guide to Cost-Benefit Analysis of Investment Projects (EU, 2014), shows that the installation heat cost allocators in district heating systems was justified and cost effective at the level of Croatia. The analysis was based on the results of previous energy analysis conducted by the Author in 2016. Results of this analysis showed that the energy savings after the instalment of head cost allocators where on the average level of 30%. Furthermore, the analysis in this paper was conducted for nine cities with district heating systems, because the price of energy varies between different systems. The price of energy is considered to be an important factor in the calculation of cost-effectiveness. The conclusion of the analysis is that the transposition of the obligation of instalment of individual measurements at end-users in district heating systems was cost-effective and that under nominal operating conditions and the level of instalment of 75% and more, of all of the apartments connected to a particular heating sub-station, good economic results can be reached.