Summary:

The assessment of a building's energy efficiency is a crucial element in estimating and minimizing its operational costs. This analysis is particularly significant in the case of large-volume structures, including public utility buildings. The aim of the conducted research was to determine the electricity and heat consumption of a public utility building, specifically the selected seat of the Commune Office in the Silesian Voivodeship (Żywiec County). The scope of the study included calculating the demand for useful energy (EU), final energy (EK), and primary energy (EP) both before and after the thermal modernization carried out in the years 2016-2019, as well as developing recommendations for further modernization aimed at reducing the energy intensity of the assessed facility. As a result of the analysis of energy indicators calculated for the building before and after thermal modernization, it was found that the construction works performed had a positive impact on the energy and economic efficiency of the facility, reducing primary energy consumption from 639.04 kWh∙m⁻²∙year⁻¹ to 143.83 kWh∙m⁻²∙year⁻¹. It is recommended to carry out further works, as a result of which primary energy consumption could be reduced to 92.20 kWh∙m⁻²∙year⁻¹ (35.9%), which will allow for achieving the technical conditions envisaged for public utility buildings by 2030.