Retrofitting the housing stock is a key requirement to address climate change targets and socio-economic issues such as fuel poverty. Improving the energy efficiency of the housing stock has become a key criterion in government manifestos due to legal obligations and socio-economic pressure. Governments have increasingly allocated funds for retrofit grants over the years to improve the energy efficiency of houses in England. This study reviewed these retrofit grants using a theory of change analysis. It was noted that the delivery of retrofits was far below the required level of retrofit to meet the objectives. Although the existing government has promised five million retrofits during the next five years, the existing retrofit grants are more likely to retrofit around 425,000 houses. It is recommended to approach housing retrofit in a broader strategy with a focus on the delivery, since just allocating funds for grants may not deliver retrofit at scale.