The origin of current climate change (unlike other past climate changes) is the increase in the so-called greenhouse effect. Several atmospheric gases can absorb infrared radiation intensively. Such gases are carbon dioxide (CO2), methane (CH4), water vapour, as well as nitrous oxide (N2O) and other gases. They are permeable to incoming radiation but block the infrared (heat) radiation reflected from the earth’s surface. These gases are called greenhouse gases. One of the solutions to reduce the greenhouse effect is to implement energy efficiency measures in multi-apartment residential buildings. The total multi-apartment housing stock in Latvia continues to age. Most residential buildings in Latvia were built during the Soviet period (1946–1990), the second largest category – even before the Second World War. Only a very small proportion of buildings have been built since the restoration of the country’s independence. As a result, the overall condition of buildings in Latvia can be assessed as poor or even unsatisfactory. Some multi-apartment buildings are so dilapidated that they endanger the safety and health of both tenants and the surrounding residents. The involvement of apartment owners and managers in the renewal of the housing stock is largely related to financing that they cannot afford to invest themselves. The support mechanism for the renovation of multi-apartment residential buildings is the European Union funds, as well as the Investment and Development Agency of Latvia (LIAA) and ALTUM. In the ALTUM programme, the maximum grant or gift limit is 50% of the total eligible costs, while the other part of the financing is covered through a commercial bank that has a cooperation agreement with ALTUM or the funds or savings of the tenants. LIAA and ALTUM support programmes have different funding models. As a result of the research, it has been proven that the renovation of multi-apartment buildings is a complex, financially expensive and complicated project that cannot be implemented without the European Union co-financing