Display Energy Certificates
Display Energy Certificates (DECs) show the actual energy usage of a building, the Operational Rating, and help the public see the energy efficiency of a building. This is based on the energy consumption of the building as recorded by gas, electricity and other meters. The DEC should be clearly displayed at all times in a prominent place clearly visible to the public.
A DEC is always accompanied by an Advisory Report that lists cost effective measures to improve the energy rating of the building.
Display Energy Certificates are only required for buildings with a total useful floor area greater than 500m2, which are occupied by a public authority or an institution providing a public service to a large number of people and are frequently visited by members of the public. Display Energy Certificates are valid for one year. The accompanying Advisory Report is valid for 7 years.
A Display Energy Certificate shows the energy performance of a building based on actual energy consumption as recorded annually over periods up to the last three years (the Operational Rating). The DEC also shows an Asset Rating for this building if this is available (by way of an EPC). A DEC is valid for one year and must be updated annually.
The Operational Rating (OR) is a numerical indicator of the actual annual carbon dioxide emissions from the building. The various types of energy consumption from occupying a building must be brought together on a common basis so that the performance of one building can be compared with that of another. The UK has decided that the common unit should be CO2 emissions, since this is a key driver for energy policy.
This rating is shown on a scale from A to G, where A is the lowest CO2 emissions (best) and G is the highest CO2 emissions (worst). Also shown are the Operational Ratings for the previous two years; this provides information on whether the energy performance of the building is improving or not.
The OR is based on the amount of energy consumed during the occupation of the building over a period of 12 months from meter readings and is compared to a hypothetical building with performance equal to one typical of its type (the benchmark). Typical performance for that type of building would have an OR of 100. A building that resulted in zero CO2 emissions would have an OR of zero, and a building that resulted in twice the typical CO2 emissions would have an OR of 200. If the building is a net energy generator, it would still be given an Operational Rating of zero.
The DEC should be displayed in a prominent place that is clearly visible to members of the public. To enable members of the public to view the document easily, it will be no smaller than A3 in size.
A DEC must be accompanied by an advisory report and the owner of the building must have a valid one available. The advisory report highlights recommendations to improve the energy performance of the building (i.e. its fabric and associated services such as heating, ventilation and lighting). An advisory report is valid for seven years, this offer includes this advisory report.