The impacts of household retrofit and domestic energy efficiency schemes: A large scale, ex post evaluation

Abstract

A large scale, ex post evaluation of the impacts of a household retrofit scheme. A new methodology to separate retrofit impacts from background trends. Shows impacts of retrofit have been 1.2-1.7 times higher than predicted. Impacts as predicted in lower income areas, higher in middle and upper income areas. Findings support the case for the wider and faster adoption of domestic retrofit. a b s t r a c tThere is widespread interest in the ability of retrofit schemes to shape domestic energy use in order to tackle fuel poverty and reduce carbon emissions. Although much has been written on the topic, there have been few large-scale ex post evaluations of the actual impacts of such schemes. We address this by assessing domestic energy use before and after the Kirklees Warm Zone (KWZ) scheme, which by fitting insulation in 51,000 homes in the 2007-2010 period is one of the largest retrofit schemes completed in the UK to date. To do this, we develop and apply a new methodology that isolates the impacts of retrofit activity from broader background trends in energy use. The results suggest that the actual impacts of the KWZ scheme have been higher than predicted, and that the scale of any performance gaps or rebound effects have been lower than has often been assumed. They also suggest that impacts on energy use in lower income areas are consistent with predictions, but that impacts in middle and higher income areas are higher than predicted. These findings support the case for the wider and/or accelerated adoption of domestic retrofit schemes in other contexts.

Housing improvements, fuel payment difficulties and mental health in deprived communities

“…A further factor may be the "rebound" effect (Hens et al 2010;Webber et al, 2015) whereby any cost savings from warmth improvements result in the system being used more and therefore have no net effect on affordability but do result in improved thermal comfort. For example, after housing improvements, occupants may choose to keep more rooms warmer and for longer, even when the rooms are not in use, or simply to prefer higher indoor temperatures thereafter (Guerra Santin 2013), possibly expecting a neutral impact on fuel bills given the expected benefits of the improvements.…”

“…The gap between the technical potential and realised effects have been studied recently by others (Webber, et al, 2015) who explain that gaps may be either due to performance gaps or rebound effects. DECC (2012) suggests that energy improvements may be as low as 50% of their potential in deprived areas, which provides some explanation for why the results may not be as strong as might be expected in this study.…”

The Role of Pilot Projects in Urban Climate Change Policy Innovation

“…In Toronto, “energy used to heat, cool and ventilate Toronto’s buildings accounts for more than 40 percent of Toronto’s GHG emissions” (City of Toronto, ). Energy efficiency can produce additional benefits beyond reducing energy use and GHG emissions, such as reduced energy bills, improved living conditions and air quality, addressing social inequalities associated with older building stocks and energy poverty, stimulating local economies, improving public health, and increased resilience of the built environment (Silverman, ; Webber, Gouldson, & Kerr, ). Golubchikov and Deda () go so far as to argue that energy efficiency retrofits can be justified solely on the basis of the social and health benefits they provide.…”

A Simple Assessment of Housing Retrofit Policies for the UK: What Should Succeed the Energy Company Obligation?

“…With domestic buildings accounting for 30% of the UK's final energy consumption [1] and 25% of UK carbon emissions [2], energy efficiency improvements in residential housing could deliver carbon savings of 24 Mt CO 2 per annum by 2030 [3]. The potential for domestic energy efficiency interventions to generate emission reductions and improve welfare has prompted urgent calls for progressing the large-scale retrofit of the UK housing stock.…”