The reason for the reconstruction of the building is the emergency construction and technical condition of the existing roofs of the pavilions and the connecting corridor. Due to the effect of leakage, the existing layers of the roof structure and the interior finishing of the surfaces in the places of seepage, as well as the external and internal walls of the building, are damaged. On all pavilions, the roofs will be insulated with mineral wool, the opening structures will be replaced with plastic windows and doors with double-glazed insulating glass. The connecting corridor in the roof part will be solved with a lamellar parametric ceiling. The insulation of the outer shell of the pavilions will be implemented with a system based on mineral wool. The heating source does not change as a result of the project, but the central heating distribution will be replaced, and new panel heaters with a thermostatic head will be installed in individual rooms. There will be a partial replacement of electrical wiring in the entire building, including the complete replacement of fluorescent, neon and incandescent lamps with LED lamps. The lightning rod will be replaced in all pavilions. In order to avoid classroom glare, external blinds controlled by a remote control will be installed in each classroom. Recuperation will be installed in the gymnasium and the school canteen, which will ensure air exchange, heating of the recuperation unit in the winter months will be provided by a heat pump, and water heating will be provided by solar heating. Rainwater from the roofs will be led to the terrain between the pavilions by roof gutters and downspouts to the rain gardens, which will not only fulfill the function of retaining water, but also an aesthetic function to beautify the entire area of the school building. The goal of the significant renovation of the elementary school building is to significantly improve the building's energy efficiency, improve the condition of the building's internal environment by improving thermal comfort, reduce energy consumption, extend the life of the public building, and contribute to the reduction of CO2 emissions.