Towards energy-efficient retrofitting of social housing in the UK: Assessing the occupant behaviour and indoor environmental quality of a council block in London

The UK is confronted with a significant challenge as it possesses one of the oldest building stocks in Europe. This necessitates extensive retrofitting efforts to upgrade these buildings and bring them up to par with the environmental requirements. This is even more challenging when it comes to social housing, where they usually suffer from poor energy efficiency and indoor environmental quality (IEQ) issues. Therefore, there is an inherent demand to understand the current environmental conditions of these buildings. This study focuses on assessing indoor air quality (IAQ), thermal comfort, occupant behaviour and energy performance with the aim of improving the current conditions and identifying strategies for achieving energy-efficient retrofits. The paper utilises a mixed-method research methodology that combines quantitative field measurements, and qualitative field questionnaires to evaluate the current state of the building's IEQ and energy performance. IEQ parameters such as air temperature, relative humidity, and carbon dioxide (CO2) levels are measured to assess thermal comfort, overall IAQ, and potential health implications for residents. These measurements were conducted using data loggers installed for 6 weeks during March and April in 13 selected case study flats within the council block. Simultaneously, weekly meter readings were also collected for each of the flats. The measurements collected by the data loggers were then compared to the UK standards, guidelines, and benchmarks to evaluate the current conditions. Moreover, the analysed data was correlated with the questionnaire survey conducted in the case study flats, to assess the impact of occupants’ behaviour on IEQ and energy performance. The findings highlight the importance of considering IEQ and occupants’ behaviours alongside energy performance during retrofitting initiatives, aiming to create healthier and more sustainable living environments for social housing residents. These results contribute to the development of evidence-based retrofitting guidelines and policy recommendations for social housing in the UK.