What is a Display Energy Certificate (DEC)?
A Display Energy Certificate (DEC) is an operational energy rating that identifies the actual energy use of a building and compares this against the energy use for a benchmark building of the same type. The operational rating is a numerical indicator of the actual annual carbon dioxide emissions from the building. A building which uses exactly the same energy as the benchmark building will have an operational rating of 100. The rating is shown on a scale from A to G, where A is the lowest CO2 emissions (or best rating) and the G band is the highest CO2 or worst rating.
Who is required to have a DEC?
From the 9th January 2013, publicly and privately owned large buildings frequently visited by the public, are required to exhibit a DEC, in a prominent place, clearly visible to the public. The DEC is intended to encourage public authorities and other owners of large buildings to adopt environmentally responsible and efficient use of energy in buildings.
How is the DEC calculated?
The DEC rating is calculated on the basis of the actual energy consumption, during occupation, over a one year period. The DEC reflects the use of the building and the practices of management and maintenance. This is calculated from meter readings/ bills or an alternative reliable source. From this, an operational rating is derived. The energy used by the building over the year is required. This may include gas fuels, oil fuels, solid fuels, district heating and cooling and electricity. Energy consumption is ideally obtained directly from onsite incoming energy meters, or from energy supply company bills. If this information is not available from those maintaining the building or the landlord, an estimate should be provided from the energy supplier.
How does a DEC differ from the BER?
A Building Energy Rating (BER) rating for domestic and non-domestic buildings is a rating certificate based on calculated energy use. *A BER is valid for 10 years
A Display Energy Certificate (DEC) rating is a rating certificate based on measured energy use. A DEC is valid for 1 year.