Impact of the energy crisis on indoor temperatures and thermal comfort in UK houses during winter 2023

• Many UK households have become unable to satisfy their thermal comfort needs. • Some households have been living in homes where temperature is as low as 12 °C. • Building occupants tend to reduce energy consumption to face high energy prices. • Building occupants can adapt to cold conditions and maintain thermal comfort. • Adaptive behavioural measures can help to save energy and maintain thermal comfort. Geopolitical, health and economic events have led to an accumulated surge in energy prices in the UK at the beginning of the 2020s. In response, studies and media reports show that households have had to reduce the running of their heating systems to cut their energy bills. However, there is limited research on the impact of this context on indoor thermal conditions and occupants’ ability to meet their thermal comfort needs. This study aimed to address this research gap. It employed the mixed-method research methodology and used nine homes in Plymouth as case studies. Undertaken research work involved monitoring indoor air temperatures for two months, January and February 2023. In parallel, a thermal comfort survey and interviews were undertaken with the residents of the examined cases. Results show that six of the nine examined households were unable to run their heating systems to warm their homes. In four cases, the average hourly air temperatures ranged between 11 and 16 °C, which is below the British Standard’s recommended temperature of 18 °C for comfortable and healthy domestic spaces. Some participants decreased their energy consumption by 27 % compared to the previous year, utilising behavioural measures to compensate for reduced heating usage and maintain a level of thermal comfort. Affected by their indoor environments, participants reported different comfort thresholds with average comfortable air temperature ranging between 12 and 20 °C. The findings of this research demonstrate the impact of energy prices on occupants’ energy usage and their ability to manage cold environments while preserving their thermal comfort.