We offer a nationwide Display Energy Certificate service throughout the UK. If you’re responsible for a public building then the chances are you’ll need a DEC. 

DECs rate the actual or operational energy performance of a building against established benchmarks and take into consideration the ways in which occupants use the building.

A Display Energy Certificate (DEC) needs to be prominently displayed in public buildings and those occupied by public authorities which have a total useful area greater than 500m2 and provide a public service to a large number of people and are therefore frequently visited by those people. The DEC has been a requirement since 1 October 2008 and shows the actual energy usage of a building.  DECs for buildings between 500m2 - 1000m2 have a 10 year validity. DECs for buildings over 1000m2 are required annually.

The operational rating on a DEC illustrates how efficiently the building is using energy. To calculate this rating a Low Carbon Energy Assessor will require information on the:

  • type of building under assessment.

  • total floor area of the building.

  • annual energy use of the building (gas and electricity).

  • methods used to heat and cool the building.


In addition, to ensure the accompanying Advisory Report provided by your Low Carbon Energy Assessors (LCEA) will provide relevant guidance to assist you in improving your Operational Rating in subsequent years s/he will benefit from the following additional information:

  • How the heating and cooling is controlled.

  • The use and method for heating/cooling water in the building.

  • Type of lighting used in the building.

  • Any onsite energy generation (renewables etc).


Some newer buildings will have this information to hand, especially if the facilities managers have been maintaining a log book or operations and maintenance manuals (O&M); but often, this information will need to be collected from a variety of documents held with separate departments within the organisation.

Our Energy Assessors are trained not only to provide you with a DEC and an EPC but to go further, to provide tailored advice to help you cut the energy costs and carbon emissions in your buildings.



Suite A, 17B Somerset House, Hussar Court Waterlooville Hampshire PO7 7SG info@rwairenergy.co.uk |

Tel: 01420 446202 or 02392 176951