Decarbonization Potential of Energy Used in Detached Houses—Case Study

Abstract

The main objectives of this study were the energy assessment of detached houses built in different periods in a central European city. A total of 236 detached houses built between 1930 and 2023 in Debrecen (Hungary) were analyzed from an energy perspective, and their CO2 emissions were measured. It was found that the net floor area of family houses built in recent years has increased but that the compactness of buildings has increased as well. The specific heat loss coefficient and the specific energy demand for heating in new buildings have decreased to 15.2% and 18.5%, respectively, over the last 90 years. Furthermore, around one third of the analyzed buildings built several decades ago must have already been renovated at least once for energy efficiency, as their heat demands are 27.6–41.4% lower than estimated. Energy consumption in six houses built in recent years was measured and studied. It was found that the occupants’ behavior may increase CO2 emissions from heating by 26%, while CO2 emissions from hot-water preparation may decrease by 38.2%. The potential of the locally available sources of renewable energy was calculated, and the costs of decarbonization packages for eight building groups were evaluated.