Climate change is the outcome of anthropogenic activities, including burning fossil fuels for generating energy. In the UK, it has been acknowledged that the majority of the housing stock will still be in use in another century. However, due to the widespread inefficient energy performance of buildings, improving the efficiency of existing UK homes has been prioritised in the government ‘s agenda in the last few decades. It has been asserted that several retrofit programmes in the UK have not achieved the expected levels of energy savings due to the ‘Building Performance Gap’ (BPG) where the predicted home energy use does not reflect the actual energy consumed. The reason of this is that energy consumption does not only rely on physical characteristics of buildings, but is directly associated to a series of socio-cultural and behavioural factors concerning occupants. Those factors need to be considered for an improved building energy operation which may consequently benefit to the future retrofit schemes.
In an attempt to address this research problem, this study aims to improve the efficiency of energy operation in the UK social housing sector post retrofit by investigating the impact of occupants’ energy consumption behaviour, occupancy patterns and socio-demographic characteristics on home energy performance. Suggestions are made for policy makers by addressing the results found during the research to improve occupants’ energy consumption behaviour. Behavioural interventions are explored including energy management applications that may help improve occupants’ energy consumption behaviour and help reduce the gap between expected and real performance.
To fulfil the research aims, the research adopts a sequential explanatory mixed-method research design where the method is primarily a questionnaire survey to collect the majority of the research data followed by a focus group interview for further interpretation. Through the practical case study of two social housing estates in London, the questionnaire survey was designed to understand correlations between occupants’ energy consumption behaviour, occupancy patterns, socio-demographic characteristics and energy performance in the UK’s social housing sector. Besides, the focus group interview was designed to further explore the barriers of energy behavioural change and obtain the feedback of occupants’ attitudes towards a series of energy management application features as a viable intervention to address home energy performance.
The results demonstrate that ‘quarterly energy bills’ are correlated with a number of energy consumption behaviours, such as the ‘use of heating controls’, ‘use of windows’ and ‘use of extractor fans’ for ventilation purposes. Besides, variances of energy performance are also identified among different household profiles, such as ‘number of children’, ‘teenagers’, ‘unemployed members’ and ‘total number of occupants’. A number of barriers to improve energy consumption behaviour are also identified during the focus group interview, such as ‘catering for children needs’, ‘daily workload’, ‘value for money’, ‘personal preferences’. The analysis also shows that those barriers are closely associated with the age groups and family sizes. It indicates that the household profiles and socio-economic factors need to be taken into consideration when designing retrofit programmes. The correlations between ‘quarterly bills’, ‘housing issues’, ‘energy consumption behaviours’ and ‘flat orientations’ also imply that the one-size-fits-all retrofit approach may also need to be altered to more tailored measures by considering the impact of solar radiation on thermal comfort. To make effective behavioural interventions, occupants’ attitudes towards different energy management application features were explored. Most interviewees preferred to receive real-time behavioural suggestions that take account of their socio-demographic information. Suggestions for other application features also include energy comparisons, socialised platform and elements of gamification design options in the energy management application.
The study found that effective and tailored design of energy use information and strategies are essential to improve occupants’ energy behaviours. Consistent and community-based approaches to disseminate energy knowledge targeting diverse household profiles are also recommended. Besides, the energy feedback and interactions with smart technologies, such as energy management applications, may be another effective way to increase occupants’ energy awareness and promote behavioural change. However, the slow progress of rolling out smart meters does not help increase occupants’ energy awareness and provide necessary infrastructure for the deployment of energy management application.