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 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.

DECs are only required for buildings with a total useful floor area greater than 1,000 m², that 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. DECs are valid for one year. The accompanying Advisory Report is valid for 7 years.

The requirement to obtain and display a DEC came into effect on 30th December 2008.

Where a building is partly occupied by a public authority or a relevant institution, the authority or institution is responsible for displaying a DEC and having a valid advisory report. Other private organisations occupying the building, irrespective of the size they occupy, do not need to display a DEC.

Although multiple small buildings on a campus where each building is less than 1,000 m² are excluded, if these buildings are linked to one another by a heated space or are served by the same heating or cooling system then a DEC is required. The energy consumption for each separate building or each group of linked buildings with total useful floor area exceeding 1,000 m², will then be derived by proportioning on the basis of floor area.

Please note - site based DECs are not acceptable in Northern Ireland.

Every building for which a DEC is required must display its own individual DEC. Where metering is at site level the DEC must be based on the metered site energy demands but with the consumption apportioned to each individual building on an area weighted basis. Although the site energy is apportioned to buildings on the same site, if different benchmarks apply to the buildings on the site e.g. a school building and a swimming pool building, then the relevant benchmark category for the building should be selected.

When using this approach the assessor should select the "estimated" energy data option within the software. The energy apportioning must be done manually as no option is available within the software to do this.

This approach was only applicable until 30th December 2009 to allow time for sub-meters to be installed in each individual building so that its DEC can be accurately calculated for the energy consumption of the previous year.

How do I get a DEC?

An Energy Assessor, accredited to produce DECs for that type of building, is the only person who can produce a DEC and Advisory Report for your building. They will use the approved calculation method for Operational Ratings.

To search for an accredited assessor to check your assessor's credentials visit www.niepcregister.com

(To download the ORCalc software please see www.ukreg-accreditation.org/ND-GovORCalc.html).

The fuel and energy consumption data you provide will be reviewed by the assessor in line with the approved method. Adjustments may be made for occupancy, intensity of use, special energy uses, weather and climate.

For the purposes of the certificate the carbon dioxide emissions are based on the adjusted energy consumption and total useful floor area and building type, giving a measured CO₂ emissions per square metre.

The assessor will then produce a DEC and an Advisory Report from this information in line with the approved method. The DEC will need to be lodged in a national register by the assessor and given a unique certificate reference number.

What does a DEC contain?

A DEC must contain the following information:

• the operational rating and the asset rating (if available) as determined by the government approved method;
• the operational ratings for the building expressed in any certificates displayed by the occupier during the last two years before the nominated date; and
• a reference value such as a current legal standard or benchmark.

The operational rating is not required where an occupier has been in occupation for less than 15 months. The asset rating is not required in the DEC where an occupier entered into occupation of the building before 31st December 2008

The DEC will also show the unique certificate reference number, the address of the building, the total useful floor area of the building, the name of the energy assessor, their employer (or trading name if self employed), the name of their accreditation scheme and the date when the DEC was issued.