The Renewable Energy Directive (2009/28/EC) requires member states to submit progress reports every two years, on the development of renewable energy (RES) use compared with their indicative trajectories in their National Renewable Energy Action Plans (NREAPs). Based on the national reports, the European Commission prepares biannual RES progress reports to the European Parliament and the Council. REKK, as a subcontractor to Navigant, contributed to the technical assistance by collecting information on the recent advancements in RES-related policy-making in the electricity, heating and cooling and transport sectors, and on the most important administrative and regulatory barriers hindering target achievement in Bulgaria, Slovakia, Slovenia, Croatia and Hungary, with the involvement of national energy experts.