How effective are regulation-based passive retrofits in adapting social housing to overheating scenarios?

Abstract

Rising temperatures pose a significant challenge for obsolete buildings, which constitute up to 30% of Europe’s building stock. Current energy renovation policies, while effective for decarbonization, exhibit a critical ’winter bias.’ By prioritizing thermal insulation without mandating adaptive cooling strategies, these regulations risk locking social housing stock into a trajectory of structural overheating, exacerbating health risks in increasingly warm climates. Moreover, in situations where households cannot afford or use air-conditioning systems and high temperatures are frequent, building retrofits should prioritise both reducing winter heat losses and passively lowering indoor temperatures during the warmer season. This research, therefore, evaluates the effectiveness of these standards under climate change conditions by projecting towards a 2080-time horizon, analysing an archetypal mid-20th century social housing case, which operates passively like many of those in temperate and warm climates. Through an assessment with a prior diagnosis based on climate evolution scenarios, a thermoenergy analysis focused on passive comfort is carried out, analysing all representative dwellings of a whole neighbourhood. The results show that, while the initial retrofit based solely on current standards results in improvements in the cold season, summer conditions worsen and there is limited improvement on the annual average. As an alternative, this study proposes an adapted improvement based on intelligent ventilation control. This could be easily implemented in refurbished buildings, ensuring thermal comfort for more than 90% of the hours of the year without relying on active climate control systems.