With an estimate that over 80% of the houses that will exist 2050 have already been built, the need to undertake retrofit measures is a critical component of strategies to reduce carbon emissions and control fuel poverty. However, given that building regulations do not apply to existing dwellings, the pace of change has been slow. Drivers include revisions of minimum letting standards such as tolerable standards, fuel poverty and eesh. Opportunities include funding packages for particular measures to meet these such as improved insulation. However an emerging concern is that is a fragmented approach that is resulting in piecemeal energy efficiency measures which, although well intended may have unintended negative consequences. This paper discusses a series of case studies of retrofit measures undertaking on a range of building types in the west of Scotland. These have been subject to Building Performance Evaluations which have examined the fabric, ventilation and environmental performance.