Combating Energy Vulnerabilities and Carbon Emissions within the Residential Sector: A Spatio-temporal Analysis of England and Wales.

Each year the English and Welsh residential sector is responsible for millions of tonnes of greenhouse gas emissions. These trends are driven by a highly energy inefficient housing stock that has an overwhelming reliance on natural gas for space and water heating. The sector further presents significant disparities in household energy consumption due to differences in occupant behaviour and property-based characteristics, which are found to vary across social and spatial structures. This inequity is best demonstrated by millions of energy vulnerable households being forced to dangerously under consume energy because of an inability to afford a socially and materially necessitated level of energy service. Addressing these disparities is crucial for fostering a more equitable residential sector that makes greater progress towards a low-carbon transition and further provides adequate warmth and energy services to those most vulnerable. Previous research has long observed the spatial disparities within the residential sector and offered evaluations for mitigation policies. However, three significant research gaps persist which impede our wider understanding of the field. Firstly, there has been an overlook in the temporal dynamics when observing the spatial variation in household energy consumption. This oversight prevents the understanding of how energy consumption has evolved across different social and spatial structures and further prevents the identification of areas with persistently high or low energy consumption. These areas are crucial for localised policy targeting of low-carbon heating systems and energy saving retrofits to decarbonise the dwelling and improve living conditions. Secondly, composite indicators have been used to estimate energy vulnerability risk by combining its known drivers and outcomes. However, these indicators have been utilised at a singular point in time. This static approach prevents the benchmarking between areas, and the ability to track progress over time. Finally, previous research that has evaluated retrofit policies has dedicated efforts to their economic impact by considering the changes in household energy consumption. This narrow approach limits our understanding of exploring a retrofits impact on a much wider range of energy-based metrics. This thesis aims to systematically address these research gaps to further our understanding of residential sector inequity and mitigation strategies. A thorough methodological framework was developed and consisted of three distinct stages that were designed to address each of the research gaps outlined above. The first detailed a sequence and clustering analysis to develop and contextualise the dominant gas consumption trajectories within granular geographies over ten years. The second developed a composite index consisting of dwelling and socio-economic variables to estimate and track changes in energy vulnerability risk within harmonised small areas in 2011 and 2021. Finally, the third methodology provided a comprehensive spatio-temporal analysis of the Green Deal retrofit policy, coupled with a difference-in-difference regression to assess its impact on multiple energy-based metrics. The findings from the three analytical Chapters advance our understanding of the spatio-temporal inequities within the residential sector and the impact of retrofits designed to improve the housing stock. The overall findings from this thesis can be categorised into three overarching areas: Spatio-temporal data and methods, substantive spatio-temporal knowledge, and offering insights for future policy recommendations. Regarding the contributions to spatio-temporal data and methods, this thesis combines annual gas consumption statistics, offers a novel sequence and clustering analysis methodology, and harmonises highly granular geographical census boundaries to aid spatio-temporal comparisons. This thesis provides substantive spatio-temporal knowledge by exploring the inequity within the residential sector by discovering the dominant gas consumption trajectories and the tracking of change in energy vulnerability risk. Furthermore, it identifies areas of persistent inequity by identifying the small areas with persistent very high or low gas consumptions and those with continually high energy vulnerability risk. Finally, this thesis provides policy recommendations by advocating for localised policy targeted support within areas exhibiting these inequities, combined with widening the scope of eligibility for retrofitting schemes to make greater progress in decarbonising the sector and improving the housing stock.