Analysing the contribution of internal heat gains when evaluating the thermal performance of buildings

To evaluate the useful energy demand for space heating purposes, norm-based bottom-up models are applied that capture the energy-related characteristics of buildings. As the electricity demand per household attributed to appliances and lighting has increased substantially in the EU27 over the last two decades, the question arises whether the static, norm-based approach is underestimating the contribution of internal heat gains to covering useful energy demand. To analyse the impact of dynamic internal heat gains in the residential sector, a bottom-up model is applied that covers the EU27 building stock with a country-specific typology. The study reveals that the norm-based approach underestimates the contribution of internal heat gains to covering thermal heat demand. Comparing the countries throughout the EU27 climate zones indicates that, on average, the static and the dynamic share of internal heat gains up to 2050 vary in a range from 20 to 70%.