A building's energy performance is defined mainly according to its energy consumption and its impact in terms of greenhouse gas emissions. An energy performance audit is mandatory for any building offered for sale or rent. The result must be included in the environmental information provided in every property advertisement.
The energy performance diagnosis describes the building's facilities and equipment (heating, domestic hot water, air-conditioning, ventilation) and conditions of use. The result is given either as the amount of actual energy consumed on the basis of historical data or as an estimate for a standard usage.