Delivering heat-resilient housing in England: Reflections on the role of overheating building regulations in a warming climate.

Climate change is causing a rise in global temperatures. High summertime temperatures can lead to overheating, where the temperature in homes becomes a risk to health and comfort. To reduce overheating in new residential buildings, a new part of the English Building Regulations, Part O: Overheating ('Part O') was introduced in 2022. This study evaluates the application of this new regulation to real-world projects. Semi-structured interviews were carried out with 30 experts across the construction and policy sectors. Experts identified that Part O has barriers to its application, including conflicts with broader parts of the building regulations, limitations in compliance modelling assumptions for passive and active technologies, a lack of futureproofing for rising temperatures, and inadequate assurance that homes designed to the regulations would be constructed to a high quality. To improve the use of Part O, this paper suggests recommendations for how the building regulations can minimise conflict, streamline processes, and support innovation to deliver heat resilient homes. This includes using academic evidence to better support technical modelling assumptions, and in the longer-term utilising upcoming modelling methodologies (Home Energy Model) to integrate Part O modelling with broader parts of building design and compliance requirements. To deliver a shift in high quality, heat resilient and net zero homes, this paper recommends a long-term shift in regulatory approaches to focus on absolute performance outputs, building audits and post occupancy evaluation.