This Information Paper deals with the issues regarding achievement of the UK government's 2050 carbon reduction target for the built environment. Focusing on the case study of the Penrhiwceiber EcoTerrace in Wales, it looks at the arguments against demolishing existing housing stock in favour of building new homes and describes the level of refurbishment that may be required when looking to improve solid wall dwellings constructed prior to 1920. This publication is aimed at housing providers, architects and homeowners who are evaluating the approach that should be taken when looking at either individual improvements or area-based regeneration. It sets out the cost of such measures and looks at a comparison with newbuild costs in the social housing sector, demonstrating that with imagination and commitment the UK's older housing stock can be made fit for the twenty-first century.