Dwelling and household characteristics' influence on reported and measured summertime overheating: a glimpse of a mild climate in the 2050's

The summer 2018 saw temperatures far above the long-term average in the Northern Hemisphere. It was England's hottest ever summer, with temperatures typical of those expected of the 2050s. In the largest and most comprehensive study to date, summertime overheating in 750 English homes was assessed through both monitoring and questionnaires.

Overheating determined using adaptive thermal comfort criteria invariably produced patterns of overheating with dwelling and household characteristics comparable with self-reported results for both living rooms and bedrooms. However, households with members aged over 75 significantly under-reported the prevalence of overheating compared with monitored results. The standard UK static overheating criterion produced implausible estimates for the prevalence of overheating in bedrooms.

Weighting the results to the national stock revealed that 4.6million English bedrooms (19% of the stock) and 3.6million living rooms (15%) overheated. Overheating was more prevalent in bedrooms at night than in living rooms during the day. The prevalence of living room overheating was significantly greater in flats (30%) than other dwelling types. Improved fabric energy efficiency did not significantly increase the risk of overheating. The prevalence of monitored overheating was greater in households living in social housing, with low incomes or with members aged over state pension age.

Recommendations are made about the measurement of overheating and the formulation of policies aimed at mitigating the risk of overheating in existing homes.