Improving energy efficiency in housing is essential to meet climate targets and reduce energy poverty across Europe. While new buildings are built to higher standards, the vast majority of existing housing stock remains inefficient. Public programmes have been launched to support renovations, but without proper evaluation, it is difficult to know whether these efforts are truly effective or cost-efficient.

This Council of Europe Development Bank's report highlights the importance of independent evaluation in assessing the real impact of energy efficiency investments. It argues that relying solely on modelled projections is insufficient. Instead, measuring actual energy savings and social outcomes helps policymakers and financiers understand what works, avoid waste, and improve future programme design.

Two case studies—one in Bulgaria and one in Poland—illustrate the challenges and successes of large-scale renovation programmes. In Bulgaria, fully grant-funded refurbishments improved living conditions but lacked post-renovation audits. In Poland, a mixed funding model showed promising results, though data collection remained limited. Both examples underscore the need for better monitoring and evaluation practices.

Finally, the report calls for more rigorous, transparent, and inclusive evaluation frameworks. It recommends that multilateral development banks and national authorities embed evaluation into programme design, collect reliable data, and consider social and behavioural factors. Doing so will ensure that energy efficiency investments deliver meaningful environmental and social benefits.