World leaders are increasingly talking about climate change, the fate of our planet and ecology, and various cross-border eco-agreements on energy saving and fuel consumption are being set up. The directive issued by the Parliament and the Council of the European Union states that, from 2021, Newly constructed buildings throughout the European Union must meet the energy efficiency class of A++. Therefore, in implementing this directive, Member States of the European Union, including Lithuania, are gradually adopting new laws regulating the energy class of buildings.