The project proposal is aimed at increasing the energy efficiency of multi-family residential buildings in Krumovgrad. The project proposal includes three residential buildings, located on 2 Treti March Street, Sq. Bulgaria 2 and St. St. St. St. Cyril and Methodius 6. Energy efficiency measures in residential buildings will be implemented on the basis of an energy efficiency audit accompanied by a valid energy performance certificate for the building and an audit to establish the technical performance of the building with a technical passport. At the stage of implementation of the project proposal, investment projects will be developed in accordance with the Spatial Planning Act and Ordinance 4 of 2001 on the scope and content of investment projects. Investment projects will include all mandatory energy-saving measures prescribed in the energy efficiency audit, including measures for the utilisation of renewable energy sources and all mandatory measures for structural restoration/strengthening of buildings prescribed in the technical audit. Energy renovation activities will provide better living conditions, thermal comfort and higher quality of the living environment. Residential energy efficiency projects will contribute to achieving the national energy efficiency target, namely to achieve a higher level of energy efficiency and indirectly to reduce greenhouse gas emissions into the atmosphere. Investments in energy efficiency measures in residential buildings on the territory of Krumovgrad will be a prerequisite for improving their building stock in order to create affordable and attractive housing. The improvement of the housing stock in Krumovgrad will lead to better air quality and improve the living conditions in them.