The project concerns the implementation of appropriate integrated energy upgrading and energy saving measures with the integration of Renewable Energy Sources (RES) systems in the building of the Municipal Gymnasium of the Municipality of Prosotsani with a total area of approximately 178331 sqm, which has insufficient thermal insulation protection while its electromechanical installations are characterized by low efficiency rates and high consumptions, thus not achieving the desired conditions of thermal and visual comfort and indoor air quality.