The project concerns energy saving interventions in the building complex that houses the school units of the 1st Gymnasium and the 1st Lyceum of Igoumenitsa with a surface area of 324167 m2. In the current situation, this building complex is characterized by low energy efficiency with large energy saving margins In order to achieve this goal, the following interventions are foreseen: Addition of a perimeter shell for the thermal insulation of external walls Thermal insulation of roofs Installation of new high energy efficiency frames with double glazing Installation of a new high energy efficiency lighting system Installation of a new heating system with heat pumps Installation of a photovoltaic system and its connection to the network of the Hellenic Electricity Distribution Network Operator HEDNO for the energy offsetting of the electricity produced net metering The above interventions are expected to be implemented within 18 months and outside the obvious reduction of the operational costs of the building complex will result in the reduction of CO2 emissions Thermal comfort optimization of lighting by achieving visual comfort the heating and cooling loads and the improvement of the quality of life since the environmental conditions within the premises are properly regulated so that students and teachers feel comfortable and pleasant At the same time the ostentatious character of the building and the systems that will be applied are expected to contribute to the awareness of the population