The certificates are commissioned by the seller (or their agent) from an accredited Energy Assessor, who visits the property to collect the relevant data to create the certificate. This data includes the age, construction and location of the building and the relevant fittings (ie. heating systems, insulation or double glazing).

The certificate provides you with a rating for the building, showing its energy efficiency and its environmental impact on a scale from A-G (where A is the most efficient and G the least efficient), in graphical format. It also contains recommended ways to improve the building's energy performance.

Predicted and interim energy assessments
Predicted energy assessments are for homes that are not yet built. When a home is designed, a predicted energy rating based on the design is produced. This must achieve, as a minimum, the target energy rating laid down for the home as specified by the energy efficiency requirements of building regulations.

Interim energy assessments are for new homes built in accordance with the energy efficiency requirements of the building regulations that came into force in April 2006. For these homes, only the energy-efficiency and environmental-impact graphs will be required, and not the full Energy Performance Certificate.