0117 403 2700 | info@sustain.co.uk

Display Energy Certificates (DECs)

We provide Display Energy Certificates and Advisory Reports for public buildings.

All public buildings with a floor area exceeding 250m2 that are frequently visited by the public require a Display Energy Certificate (DEC). We produce DECs and Advisory Reports (ARs) for affected buildings, ensuring that their energy performance is reported and displayed correctly. 

We carry out detailed energy surveys, face-to-face questionnaires and information processing using approved software to produce your building’s DEC and AR.

All work is carried out by our qualified and accredited energy assessors, who have been carefully chosen for their commitment to safety, quality and data confidentiality.

Display energy certificates

A Display Energy Certificate is a mandatory document which shows the actual energy usage – the operational rating – of a building. All qualifying public buildings are required to have a visible Display Energy Certificate in their building and an accompanying Advisory Report which provides recommendations on how a building’s energy performance can be improved.

The DEC provides an energy performance operational rating, from A to G, which indicates how efficiently the building is being used. This energy rating is based on the performance of the building fabric and its services – including heating, ventilation and lighting.

The validity period of your DEC and Advisory Report depends on your building’s useable floor area:

  • A Display Energy Certificate or Advisory Report is not required
  • Display Energy Certificates must be renewed every 10 years
  • Advisory Reports must be renewed every 10 years
  • Display Energy Certificates must be renewed every year
  • Advisory Reports must be renewed every 7 years


Our qualified and accredited energy assessors work to your specific DEC needs, including DBS clearance and out-of-hours work where required.



Our DECs and Renewals service is designed to provide you with a new or renewed DEC as required by law. This service includes:

  • Site surveys (if required)
  • A valid DEC
  • Advisory Report
  • Annual renewals

If the standard AR does not provide enough detail for your requirements, choose our DEC PLUS service which gives an in-depth description of the improvements you can make, including realistic costs and benefits.

  • Advanced Site Surveys
  • A valid DEC
  • Advisory Report
  • Action Plan with fully costed recommendations
  • Energy Saving Opportunity Report
Talk to Sustain about Display Energy Certificates