The project “Policies to finance energy efficiency” rigorously evaluates efficiency financing facilities using advanced econometric methods. The aim of the study is to, first, identify market failures that stifle the financing of energy efficiency, and, second, suggest policy interventions that may address these failures. Special attention is given to whether loans or subsidies are better suited to finance efficiency. In addition to specific policy tools, the analysis also takes into account the performance of financing facilities. The study focusses on the housing sectors in the UK, France, and Germany.