Electrifying residential heating systems toward carbon-neutral buildings: a retrofitted building stock in Northern Italy

The electrification of residential heating systems is a key strategy for reducing fossil fuel use in existing urban building stocks. This study analyses monitored operational data from a set of residential building blocks in Milan, where gas-based boilers were replaced with ground water heat pumps as part of large retrofitting measures. Energy consumption data, collected before and after the activation of the heat pumps, were converted to primary energy and normalised using heating degree days to account for climatic variability of the considered periods. The analysis compares heating performance across building blocks by investigating how primary energy consumption responds to climatic demand and highlighting the potential impact of heating systems' electrification.