The energy certificate is used to evaluate buildings in terms of energy. The final energy consumption and the primary energy consumption are stated in kWh/(m² * a). This makes it easier to compare buildings with each other. There are two types of certificates. On the one hand, there is the consumption certificate, in which the energy quantities actually consumed over the last three years are stated, adjusted for weather conditions, and on the other hand, the demand certificate. In the latter, the demand for heating, cooling, ventilation and hot water is calculated, taking into account the insulation properties and heating technology.