DECs are now admissible as part of ESOS Regulations 2014 which require companies that employ more than 250 people or have an annual turnover in excess of 50 million euros and a balance sheet in excess of 43 million euros.

The ESOS Regulations 2014 bring into force Article 8 of the EU Energy Efficiency Directive and mandate that all large businesses in the UK undertake comprehensive assessments of energy use and energy efficiency opportunities at least once every four years.

The deadline for the first compliance period is 5 December 2015, by which time qualifying businesses will have to achieve compliance with the regulations and notify the Environment Agency.

A Display Energy Certificate shows the buildings Operational Rating and should be displayed in a prominent position in the building.

A DEC provides a visual energy performance rating based on actual energy consumption recorded annually.

Each DEC has an Operational Rating (OR), which is a numerical indicator of the actual annual carbon dioxide emissions from the subject building. Various criteria are employed to ensure that the energy performance of one building can be compared with that of another

A DEC is valid for one year and must be updated annually.

A building is given a rating on a scale from A to G with A being the lowest CO₂ emissions and G being the highest CO₂ emissions. Operations ratings from previous years are also displayed on the certificate to show the changes in the building’s energy performance. An Operational rating of 100 is the Government benchmark, which is a typical energy consumption for that type of building. The OR is produced using a software tool made available by the Government called the Common Information Point (CIP) by an accredited energy assessor to calculate the CO₂ emissions.

From 9^th July 2015, a DEC and advisory report are required for buildings with a total useful floor area over 250m² that are occupied in whole or part by public authorities and frequently visited by the public.

For the purposes of the regulations, a building is defined as, ‘a roofed construction having walls, for which energy is used to condition the indoor climate, and a reference to a building includes a reference to a part of a building which has been designed or altered to be used separately’.

For a building to fall within the requirement for a DEC it must:

• Have a roof and walls; and
• Use energy to condition the indoor climate. This is the case where the building has any of the following fixed services: heating, mechanical ventilation or air conditioning

A building can either be:

• The whole of a building; or
• Part of a building, where the part is designed or altered to be used separately

Only buildings, with a total useful floor area greater than 250m², occupied by a public authority and frequently visited by the public are affected by this legislation.

Private organisations, including those that may share a building with a relevant institution, do not need to display a DEC, but may elect to do so on a voluntary basis.

A Public Authority – which includes local and national governments, NHS Trusts, MOD, schools and universities, executive agencies and regulatory bodies; A body that provides a public service – including services provided by local or national governments.

DECs must be carried out by a qualified energy assessor.

From 1st October 2008 buildings are also required to have an Advisory Report (AR), which is valid for seven years. The AR is a list of short, medium and long term alterations that can be made to the existing building to reduce total CO₂ emissions. Although recommendations within the AR are not required by law to be implemented if the recommendations are followed, the total CO₂ emissions will be reduced and long term savings can be made. The energy assessor can also include additional item that he/she believes will aid in reducing CO₂ emissions at the end of the AR in addition to those selected by the assessor from the list produced by the software.

Energy meter readings of the last 15 months, floor plans, and details of the building and energy services.

All relevant information is then entered into the approved software program, which is regularly updated and the DEC and AR are then produced.

If the occupier of the building cannot provide meter readings or floor areas, the energy assessor will be required to contact the main energy suppliers to obtain actual meter readings and will carry out a measured survey of the building to confirm total floor area. This will necessarily result in greater time being spent in producing the DEC, which will have an implication on the fees charged. The completed DEC and AR are lodged in a national register and given a unique certificate reference number, which is detailed on the DEC and can also be found on http://www.ndepcregister.com

The DEC will need to be displayed in a prominent and clearly visible place in all relevant buildings.