Space heating and the preparation of domestic hot water (DHW) account for the highest energy consumption in Croatia. These needs make up over 80% of the total energy consumption in multi-family buildings and houses in Croatia. Many multifamily buildings fall into low energy performance categories. In line with European Union trends, which focus on highly efficient energy use for heating, there is a need for the energy renovation of the observed households. European directives, as well as national strategies and programmes initiated by the Government of the Republic of Croatia, encourage the renovation of energy-inefficient residential spaces to achieve the energy efficiency levels of other EU member states. This paper provides a detailed analysis of the heating systems in multi-family buildings and households, examining energy consumption for heating and DHW. The thesis presents a methodology which describes relevant components which were used in the research and the methods for data collection and processing. Also, the paper presents indicators that clearly show energy consumption in households, along with an analysis of CO2 emissions and primary energy related to energy consumption. The main findings of the research include the average consumption of energy sources used for generating thermal energy and CO2 emissions in the observed residential buildings. Energy consumption is expressed through established consumption indicators, specifically the indicator of the number of people supplied with energy and the indicator of the square meter area covered by a particular thermal energy source. The analysis of the obtained data revealed that single-family homes, on an annual basis, consumed an average of 27.97 kWh/m² of electrical energy, 139.29 kWh/m² of thermal energy, and 77.95 kWh/m² of natural gas. In addition to single-family homes, the energy consumption for multi-family residential buildings was also analyzed. The analysis of the collected data showed that multifamily residential buildings annually consume an average of 38.99 kWh/m² of electrical energy, 119.85 kWh/m² of thermal energy, and 131.57 kWh/m² of natural gas.