The certificate-based cost estimate covers heating, ventilation, cooling and hot water; it excludes appliances and lighting. See the tariff and comparison assumptions below.
The certificates state how much energy each home buys from the grid after its own production: 14.85 to 16.91 kWh per square meter a year. At PLN 0.97 per kWh (tariff G11, Kraków, 2026) that is about PLN 1,573 a year in a 96 m² home, PLN 1,768 for 119 m² and PLN 2,105 for 146 m². A gas-heated home of the same size with the average Polish characteristic is calculated at PLN 4,847, 5,982 and 7,281. The difference is PLN 3,274 to 5,176 a year, a calculated bill 3.1 to 3.5 times lower.
Assumptions: reference home of the same usable floor area at EP 161.7 kWh/m²·year (average Polish single-family home, PKO BP analysis of the housing stock), natural gas at PLN 0.33 per kWh gross with distribution plus a PLN 193 standing charge a year; gross 2026 prices. Calculated indicators describe the building, not the behavior of its occupants; real consumption may differ. The figures are not converted to other currencies.