Evaluating retrofitted external wall insulation

Abstract

The aim of this doctoral research project is to investigate the link between the construction quality of retrofitted external wall insulation (EWI) and the resulting impact on energy performance of existing dwellings in Swansea. Four contributions to knowledge are documented. The first is a methodology for simultaneously obtaining empirical data about the construction quality and energy performance of dwellings receiving retrofitted EWI. The findings demonstrate the value of assessing the construction quality of retrofitted EWI alongside energy performance. The appraisal of energy performance alone could have indicated misleading results due to the omission to identify latent factors, such as thermal bridging, which were identified whilst assessing the construction quality of the retrofitted EWI. The second contribution is a methodology for assessing the construction quality of retrofitted EWI, which can be used as part of the quality control process for future installations. Through the collection and analysis of triangulated field observations of photographs, as-built technical details and qualitative external thermographic surveys, the findings indicate that this methodology provides robust results for assessing the design and execution of retrofitted EWI. The third contribution is baseline energy performance data for traditional dwellings in south west Wales. The data documenting these results are set out for each case study dwelling, which includes energy consumption and carbon emissions, together with the dwelling type, tenure and number of occupants. The fourth and final contribution is a EWI retrofit case study of traditional dwellings in south west Wales. This is the culmination of the entire doctoral research project, which as a whole does not currently exist in the literature. Collectively, all the individual case studies make up the overall case study documenting the construction quality and energy performance of traditional dwellings in Swansea, which have received retrofitted EWI through phase one of the Welsh Government’s Arbed scheme.