A building's energy class is determined by its annual energy consumption per m². Lower consumption means a higher class (A is best, G is lowest).
Where to get the data
Annual consumption (kWh) - from electricity and gas bills for the year. Add meter readings or kWh from invoices. If heating is gas - add gas (convert m³ to kWh using the factor on your bill, usually ~10 kWh/m³).
If you have an energy certificate or passport - it may list specific consumption (kWh/m²/year) directly.
Calculation formula
Specific consumption = Annual consumption (kWh) ÷ Area (m²). Unit: kWh/m²/year. EN 15217 standard.
| Class | Consumption (kWh/m²/year) |
|---|
| A | up to 50 |
| B | 50 - 90 |
| C | 90 - 150 |
| D | 150 - 230 |
| E | 230 - 330 |
| F | 330 - 450 |
| G | over 450 |
