The building of the 7th Primary School of Mytilene, requires extensive work on both the building shell and the electromechanical installations, in order to achieve further energy savings, in order to upgrade it to an energy category. In order to achieve this upgrade, work is included concerning, in general, the replacement of frames (frame-glass panels), a new low thermal permeability factor, the thermal insulation of the roof and the upgrading of the E/M installations (Heating-Lighting).