Energy efficiency is widely viewed as one of the most effective ways to achieve multiple economic, social and environmental benefits and is at a core of making significant progress towards Sustainable Development Goals (SDGs) and the Paris Climate Agreement. This publication presents the outcome of a survey among the energy efficiency practitioners on the challenges and solutions for overcoming barriers to energy efficiency investments. The primary geographic focus is the UNECE region comprising 56 member States from Western Europe (members and non-members of the European Union), North America (Canada and the United States), South-East Europe, Eastern Europe, the Caucasus, Central Asia, Israel, Turkey and the Russian Federation. This is a joint effort by the UNECE and the Copenhagen Centre on Energy Efficiency. The analysis of the survey and its conclusions and recommendations will serve as a useful tool for energy efficiency community. Policy makers can apply the results to the situation in their countries and find approaches to improve investment climate for energy efficiency.