In the UK, a pressing issue has emerged concerning the heat resilience of homes. With the population spending approximately 90% of their time indoors, the capacity of the existing housing stock to handle excessive heat is alarmingly inadequate. This situation has resulted in millions of homes across the UK suffering from summertime overheating.

The introduction of Part O of the building regulations, targeting the overheating mitigation requirements in new residential buildings, marks a commendable initiative. However, its scope is limited and necessitates expansion.

It is crucial to extend the reach of Part O to encompass not only new constructions but also the refurbishment of existing properties and buildings undergoing material changes to residential use. This expansion would ensure a broader impact, promoting heat resilience in a larger number of homes. Additionally, implementing post-occupancy evaluations is vital. These evaluations would assess the real-world effectiveness of the mitigation strategies deployed under Part O, preferably within the first year after installation. Such measures would provide valuable insights into the practical benefits and limitations of current regulations, leading to more informed future policies.

The challenge of retrofitting existing homes to enhance their heat resilience is immense, given that four out of every five homes that will exist in 2050 are already constructed. Addressing this challenge requires a multifaceted approach. The integration of existing initiatives focused on insulation and energy efficiency into a more ambitious, all-encompassing housing retrofit programme is necessary. This programme should not only aim at improving energy efficiency but also at mitigating overheating risks. A well-designed and executed approach can achieve cost-effectiveness, minimal disruption, and ensure that homes are both energy-efficient and comfortable.

A locally-led strategy, implemented through local authorities, is recommended for the delivery of this programme. Local authorities possess an intimate understanding of their respective areas and communities, making them ideal for spearheading such initiatives. Adequate long-term funding is essential to support these efforts. The strategy should prioritise passive measures, such as better insulation and natural ventilation, and then fans, before resorting to more energy-intensive 'active' cooling methods.

Furthermore, the role of private finance in achieving the necessary scale of retrofitting cannot be understated. The government must urgently propose ways to facilitate access to low-cost finance for homeowners. This action is especially pressing in light of the consultation carried out three years ago, which has yet to yield substantial progress. Such financial support would significantly accelerate the retrofitting process, making sustainable cooling and heat resilience a reachable goal for a vast number of UK homes.

Addressing the issue of heat resilience in UK homes requires a comprehensive, multi-tiered approach. Expanding the scope of Part O, conducting post-occupancy evaluations, integrating various initiatives into a broad retrofitting programme and facilitating private finance are critical steps towards ensuring that homes are not only energy-efficient but also capable of withstanding the challenges posed by rising temperatures.

Read the full report by the Environmental Audit Committee here.