Low carbon design strategies for building retrofits - the case of the 1930s semi-detached house in Wales

In the context of climate change, fuel poverty, and their impacts on the built environment, European Commission set ambitious goals for energy and carbon reduction as a response to the ongoing crisis. To meet energy needs and targets, the UK government set a goal to reduce greenhouse gas emissions by at least 80% in the UK. This article presents the design strategies and tools to enable the analysis of the energy efficiency performance of buildings. It involves the considerations of a set of building alterations and the carbon footprint of different materials. In this paper, the most efficient retrofit solution among the alternatives was reached using the calculator tools for typical Welsh houses. Meanwhile, a more cost-efficient approach is also considered, including the alteration cost, payback period, and installation process in economic terms. The methodology is applied to a case study - the 1930 semi-detached house in Wales. The result shows a successful building retrofit strategy with an 85% carbon reduction (exceeding the EU targets), indicating effective solutions for low-carbon building designs. The limitation of this paper is that the tool adopted, such as the SAP system, can only be used in different regions within the UK. This article aims to develop a new design framework integrated with real case applications to support more practical low-carbon building designs.