The impact of climate change on building heat demand in different climate types

•The difference in heat demand decrease rates between weather scenarios was minor.•Reduction in heating hours was almost negligible in colder climates considered.•In warmer climates, heating hours decrease rate was significant.•Heat demand decrease could impact heating systems operational parameters. Heat demand may decrease in the future due to changing weather conditions and building renovation policies, possibly impacting the efficiency and profitability of renewable heat production and distribution systems which are commonly proposed in the literature as an adequate measure for building sector emissions mitigation. In this work, the potential evolution of building heat demand in characteristic locations (within heating dominant climates) is assessed for different scenarios by using a sample building as a case study. Three future weather scenarios were created based on a previously developed methodology, along with one building renovation scenario based on market penetration rates of different renovation measures. Heat demand was calculated through a heat demand model previously developed and validated by the authors. To represent the results, heat demand-outdoor temperature function parameters were used. The results indicated that the impact of changed weather conditions was significantly lower than the impact of building renovation. Overall, the difference in the parameters rate of decrease/increase was lower than 2% between weather scenarios for the same year considered. After the initial building renovation in 2020, the slope coefficient of the outdoor temperature-heat demand function increased between 45% and 51%, while the intercept decreased within the range of 48% and 51% (depending on the weather scenario and location considered). The reduction in the number of heating hours was almost negligible in the colder climates considered, while in the warmer climates the decrease rate was significant – 0.8% and 43% of heating hours respectively in 2050 compared to 2010, for the medium weather scenario. Such decrease in demand and heating hours could significantly impact the operational parameters of heat production and distribution units, as well as their feasibility.