The criterion for classifying an object as a <strong>low-energy object</strong> is the limitation of its energy consumption to <strong>48 kWh/m<sup>2</sup>/year</strong>. By building low-energy buildings, with negligible additional investments (from 5% to 10% of the total investment), and due to the short payback period, large energy savings are achieved. It should be noted that 70% of the total energy consumption "goes" to space heating. At the same time, the construction of such facilities achieves extremely significant reductions in the emission of harmful gases (CO2). For example, a low-energy building emits almost twice as many harmful gases per year as a building built on the basis of basic building regulations, and a "passive house" as the "most extreme" example of a low-energy building emits up to 5 times less than a low-energy building.