A Display Energy Certificate (DEC) measures energy performance based on actual annual energy usage.

The operational rating is a numeric indicator of the amount of energy consumed during the occupation of the building over a period of 12 months, based on meter readings. The indicators of operational performance are annual carbon dioxide emission per unit of area of the building caused by its consumption of energy, and benchmarked to a value that would be considered typical for the particular type of building.

In England and Wales a Display Energy Certificate is require for all public buildings whilst in Scotland a public building requires an Energy Performance Certificate. 

In Scotland the production of an annual DEC is a way of deferring any required Section 63 Action Plan improvements as in the The Assessment of Energy Performance of Non-domestic Buildings (Scotland) Regulations 2016.

Where, under those regulations, a building owner chooses to report annual operational energy use, the Display Energy Certificate (DEC) must be lodged to the Scottish EPC Register annually.

Building owners and building tenants may elect to implement Operation Rating measures on a voluntary basis or in response to other legislative requirements, such as the UK Energy Savings Opportunity Scheme (ESOS)4 which requires energy audits and reporting on the performance by most large (non-SME) companies.

In such cases, building owners should be aware of any reporting requirements imposed by legislation, for example, obtaining both a DEC and the accompanying Advisory Report.

DOWNLOAD AVAILABLE: Display Energy Certificate - briefing paper