Initially a certified surveyor has to inspect the property and label the energy efficiency level of it based on a given classification. Besides structural features, the energy usage of the heating and cooling system, ventilation and hot water system must be taken into consideration.
The certificate is valid for 10 years and it contains recommendations with regards to saving energy. The reference number of the certificate (seven digits) must be documented in the sales contract.
Inspection: If there are no documents available containing the property layout, a property plan also has to be made. In the process of filling in the classification form, the width and type of the bordering structures (walls, roofing, windows) need to be recorded, furthermore, heating and hot water producing appliances must be identified individually. Photographic documentation of the property and its engineering is also required in order to support future calculations. As for an average size flat/house, the inspection is likely to last for about 30-60 minutes, depending on the size of the property.
Contents of the certificate: The first part of it is a summary, the second one contains supporting information with the documented data and partial results.