Adaptive thermal comfort and healthy home metrics among minority households in the United Kingdom

Ethnic minority households in the UK face compounded challenges in maintaining thermally comfortable and healthy indoor environmental conditions. Policy efforts tend to prioritise cost reduction and decarbonisation over indoor health, often assuming that achieving thermal comfort automatically ensures healthy living conditions. This assumption is questionable, especially for vulnerable and minority households who frequently live in cold, damp, and energy-inefficient homes that are Complex-to-decarbonise (CTD). This study explores the current gap between thermal comfort and health metrics based on longitudinal field measurements within one minority group in the UK, to assess whether thermal comfort metrics reflect healthy indoor conditions. Quantitative high-resolution data were collected from eleven minority households using Internet of Things (IoT) sensors recording temperature and relative humidity (RH) in the living areas over a one-year period. When looking at overheated and underheated conditions during annual occupied hours (7:00 am to 10:00 pm), all 11 cases had periods of cold stress, with temperatures below 18°C for up to 72% of annual occupied hours. Periods of overheating were observed in 8 cases, with temperatures over 26°C for up to 11% of the annual occupied hours. A dry living area was observed in one case, for up to 5% of the annual occupied hours. Excessively humid living areas with RH above 60% were identified in all cases, for up to 91% of annual occupied hours. This study applied a practical taxonomy to identify thermal and health stresses that may disproportionately affect minority households. The findings from this study demonstrate that relying on thermal comfort metrics may obscure unhealthy indoor conditions. Therefore, a combined approach linking thermal comfort and health is essential and will be beneficial for architects, academics, practitioners, and policymakers who are concerned with thermal health, inclusive and equitable approaches for home decarbonisation.