DEC’s came into force on 1st October 2008. The Department of Energy, and Climate Change, state that the purpose of introducing DEC’s was to raise public awareness of energy use, with a view to steering the governments carbon reduction frameworks, whereby a cut of 80% from 1991 CO2 emissions rates is required by 2050.

Display Energy Certificates (DEC) shows the operational rating (OR) of a building based on actual energy consumption taken from billing data over 12 month period. This information 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.  The purpose of a DEC is to evaluate the actual or operational energy performance of a building in comparison to established benchmarks. It takes into account the behaviour and energy usage patterns of the occupants within the building.

An Advisory Report (AR) accompanies the DEC, and is a document that highlights various recommendations to improve the energy performance of the building. Such recommendations may be operational and management improvements, possible upgrades to the building fabric or services, and opportunities for the installation of low and zero carbon technology

Who needs a DEC?
Currently the requirements for DEC’s only lie with public buildings, otherwise defined as a building occupied by a public authority or institution providing a public service to a large number of people and therefore frequently visited by those persons.  All buildings above 250m² require a DEC.

I have multiple buildings on one site, can I have one DEC?
In simple terms, no!  Each building is required to have a DEC.  There are the occasional exceptions, such as 2 buildings being connected in some way or they share the same energy meters but generally this is not the case.