No department owns heat resilience in homes

The CCC finds no single department owns residential overheating. Building Regulations Part O covers only new-build, is weakly enforced and is misaligned with the energy-efficiency Part L; nothing addresses the existing stock, and there is no support scheme for heat-vulnerable, low-income households. MHCLG owns building standards, DHSC/UKHSA own heat-health alerts and DESNZ owns retrofit - but none owns the outcome. 2025 was the UK's hottest year on record.

By 2050 the CCC projects the majority of homes at risk of overheating and heat mortality rising sharply. Split responsibility means no one is accountable for keeping people alive during heatwaves indoors, where most heat deaths occur.

A named lead department for heat resilience, a passive-cooling retrofit programme for existing and social housing, enforced Part O across all tenures, and targeted cooling support for heat-vulnerable low-income households.

// State-led: Instrument: machinery-of-government designation of a lead department, Part O regulatory extension and funded retrofit programme.

Nobody owns residential overheating despite 2025 being the hottest year and mortality rising toward 2050, and naming a lead department is easy, yet no dated policy trigger forces it.