The energy certificate is a document that evaluates a building in terms of energy. It gives you a rough estimate of the future energy costs for an apartment or house and makes the energy requirements of houses comparable.

Energy certificates must be submitted for new buildings and when buildings are sold, leased, rented or leased.

There are two types of energy certificates. They differ in the calculation method.

• Energy certificate

The energy certificate is issued on the basis of the calculated energy demand of the building. This procedure is mandatory for new buildings. This demand-oriented energy certificate calculates the energy demand on the basis of the condition of the building envelope and the building services under average user behaviour. In the simplified procedure, the data is recorded via a typology of the building form, components, year of construction, etc., the detailed procedure records in detail the building to be examined and its building services.

• Energy consumption certificate

The consumption-oriented energy certificate reflects the weather-adjusted consumption of the building over at least the period of the past 3 years. The result depends in certain cases strongly on the user behaviour in this period. The heating and ventilation behaviour have an effect on the result.

Only qualified experts are authorised to issue energy certificates. The requirements for the qualification of the issuers are regulated by law. However, there is no certificate or other document confirming the right to issue energy performance certificates. However, several website operators offer expert searches on the Internet.