Net zero retrofit of older tenement housing - The contribution of cost benefit analysis to wider evaluation of a demonstration project

The United Kingdom is legally committed to net zero by 2050; Scotland by 2045. How much will retrofitting older homes contribute to meeting net zero? What lessons can we learn from demonstrator projects? We present results from a social cost-benefit analysis of a demonstrator retrofit carried out on a Victorian tenement building in Scotland. The paper discusses the process and implications of this analysis, while also providing lessons learned from the wider evaluation. The cost-benefit analysis indicates that retrofitting provides better social value than demolition and new building in this project. However, the optimal amount of investment in retrofitting is sensitive to the assumptions made. Furthermore, the wider evaluation findings suggest it may be difficult to transport findings from any one setting to another. Local context matters.