In this Master thesis an evaluation of energy renovation measures and of chosen solutions for solving problems regarding metering and billing of heat consumption are presented. For this purpose, a case study of a residential building in Zagreb has been chosen. An extensive literature review, data collection, and a numerical modelling have been carried out to present potential solutions. Apart from presenting the current situation in the residential sector, in both the EU and Croatia, a methodology behind the data collection and the model have been given with the main aim of representing the model which corresponds to the real-life case. After the validation of the model, renovation scenarios have been developed to evaluate the most cost-effective solution. Results include heat savings, investment costs and the payback time of all solutions. Furthermore, several options for solving problems regarding the metering and billing methodology have been selected and examined by comparing the investment costs and the possibility for fostering incentives for heat savings by changing habits and behaviour of the residents.Lastly, a critical discussion is presented to reflect on assumptions, limitations, and decisions made together with the conclusion to sum up the outcomes of energy renovation and remodelling of the existing metering and billing methodology.