The European Union, which the Republic of Croatia has been a member of since 2013, tries to prevent climate change in every possible way . One of the main decisions in the attempt to control environmental pollution and prevent climate change is to increase energy production from renewable energy sources and to reduce energy consumption and loss as much as possible as well as to increase the energy efficiency of buildings. To achieve a highly efficient facility, it is necessary to invest quite a bit of money and to have a lot of knowledge about new highly efficient technologies. In order for this to be achieved in the best possible and affordable way the Government of the Republic of Croatia, together with the European Union, awards grants in the form of co-financing mostly for renewable energy sources and high-quality thermal insulation. For energy efficiency to be at the highest possible level, it is necessary to apply some of the measures such as highly efficient thermal insulation to prevent the loss of temperature into the environment, efficient space heating in the form of heat pumps (the most efficient water-water), using solar energy as much as possible for the production of electricity at the point of consumption with the help of solar power plants on the roofs of buildings. After using all possible options for reducing consumption and increasing self-sufficiency, the facility becomes highly efficient and thus reduces its total consumption, which ultimately has a positive impact on the environment itself.