From building codes to behaviour: Strengthening extreme heat adaptation policy in the United Kingdom

Climate change is driving increasingly frequent and intense heat events in the United Kingdom, with summer 2025 recorded as the hottest on record. Despite growing risks, significant gaps remain in how heat adaptation is addressed across regulatory frameworks, institutional systems, and behavioural responses. This policy perspective draws on a cross-sector roundtable held in July 2025, bringing together practitioners, housing providers, and researchers. The insights from the roundtable are situated within existing literature on building design, retrofit policy, and behaviour change. Findings reveal major shortcomings in current regulatory frameworks, particularly Part O of the Building Regulations. Key issues include fragmented and sometimes conflicting requirements, limited consideration of future climate scenarios, a compliance-driven rather than resilience-oriented approach, weak oversight and enforcement, and persistent social inequalities that leave vulnerable populations disproportionately exposed. Beyond regulatory gaps, behavioural and institutional barriers further constrain adaptation, including low public risk perception, inadequate heat risk communication, limited integration of heat resilience into health and care systems, and significant evidence gaps in high-risk settings such as care homes and prisons. Effective heat adaptation requires coordinated regulatory and behavioural responses. Policy priorities include strengthening Part O to cover both new builds and retrofits, extending protections to vulnerable settings such as healthcare and social housing, integrating active and passive cooling strategies, and improving enforcement and future-proofing of standards. Behavioural adaptation must also be strengthened through targeted risk communication, evidence-informed health planning, and more coordinated action across housing, health, and climate policy systems.