Understanding the decarbonisation of housing: Wales as a case study

International targets requiring UK nations to reduce carbon emissions by at least 80% of 1990 levels by 2050 were made obsolete in 2019. The Climate Change Act now commits UK government to reducing greenhouse gas emissions by at least 100% of 1990 levels by 2050. This includes more stringent emissions targets for the devolved administrations. Welsh Government is responsible for the delivery of decarbonisation in Wales. The Welsh housing stock, among the oldest and least efficient in Europe, produces 21% of national carbon emissions. The CCC report recommends that Wales target no less than a 95% reduction in carbon emissions by 2050. This research explores how policy could deliver this scale of emissions reduction, by predicting the impact of established and emerging 'best practice' retrofit solutions on the existing housing stock. Fourteen recurring dwelling 'types' are identified within the Welsh housing stock (based on physical metrics, condition and tenure) using large data sets. Appropriate retrofit 'narratives' are established and then simulated for each of the fourteen dwelling types. Their impact is measured in terms of capital cost, primary energy use, fuel bills, and carbon emissions. By exploring the impact of a range of approaches to retrofit, and by considering different scenarios for clean energy supply, this research has informed the ongoing development of a route map for delivering decarbonisation targets in Wales