The physical object of the operation aims to improve the energy performance of the two buildings of the Primary School of Tsotyli in the Municipality of Voio with a view to the energy upgrade of the buildings from the energy class according to KENAK category H in category B Primary School of Tsotyli provided the following interventionsInternal thermal insulation works of the shell of the old building External thermal insulation works of the shell of the new buildingThermal insulation of the roof of both buildings Replacement of all existing frames of the old building with new wooden with better energy characteristicsReplacement of all existing frames of the new building with new aluminum with better energy characteristicsReplacement of lighting bodies and lamps with a new type of LED in both buildingsReplacement of the central heating system in both buildings with a new high-performance water heat pump and temperaturesEdition of Energy Performance Certificates of the buildings after the implementation of the interventions of the energy upgrade