What is a DEC?
A Display Energy Certificate (DEC) is an official document used to show the actual energy usage of a building, specifically, how efficiently it uses energy based on real metered consumption.
Eligibility and Scope
DECs are required for public buildings that are frequently visited by the public and have a total floor area over 250 m² (e.g. schools, hospitals, council offices, libraries).
Key Objectives
DECs promote energy efficiency in public buildings, increase transparency by showing the public how much energy a building actually uses, and encourage building owners and occupiers to improve their energy performance.
The principle is that, since these buildings are publicly funded, the public has the right to see how efficiently they’re run. Display Energy Certificates promote accountability and energy efficiency across the public sector.
A DEC must be displayed in a prominent place visible to the public (usually a reception area or entrance)
Display Energy Certificates must be accompanied by a valid Advisory Report
What information does a Dec contain?
Operational Rating (A-G)
Based on actual energy consumption as opposed to the building’s design efficiency. A is the highest rating and G is the lowest.
Comparison Information
Compares the building’s performance to similar buildings.
Summary of Energy Use
Shows yearly CO₂ emissions and energy consumption for electricity, gas, and other fuels.
Validity
For buildings over 1000 m², DECs are valid for 1 year.
For buildings between 250 m² and 1000 m² DECs are valid for 10 years.
What does an Advisory Report entail?
Issued alongside the DEC is an Advisory Report (AR), which provides:
- Recommendations for improving energy efficiency.
- Payback estimates for suggested measures.
The AR is valid for 7 years, whilst the DEC itself will need renewing either annually or ten-yearly, depending on the size of the building. The absence of a valid Advisory Report can result in a financial penalty.
Legislation Governing Display Energy Certificates
Display Energy Certificates were introduced in response to the EU Energy Performance of Buildings Directive (EPBD). The EPBD Directive 2002/91/EC, later recast as Directive 2010/31/EU, required EU member states to implement systems for assessing and displaying the energy performance of buildings.
The legislative basis for Display Energy Certificates within the United Kingdom
In the UK, DEC legislation came into force around 2008 following the introduction of The Energy Performance of Buildings Regulations 2007, made under the European Communities Act 1972. These regulations set out the framework for Energy Performance Certificates and Display Energy Certificates.
Revisions to Display Energy Certificate regulations
The rules have been updated several times, notably by The Energy Performance of Buildings (England and Wales) Regulations 2012, and subsequent amendments in 2015, 2018, and later years. These updates refined:
- Buildings subject to DEC requirements
- Certificate validity periods (1 year for properties over 1000 m², 10 years for 250–1000 m²)
- Requirements for the Advisory Report accompanying the Display Energy Certificate
Failure to PrESENT a DISPLAY ENERGY CERTIFICATE
Under The Energy Performance of Buildings (England and Wales) Regulations 2012, as amended, the penalties are:
- Up to £500 fine if you fail to display a valid DEC.
- Up to £1,000 fine if you fail to have a valid Advisory Report.
Local authorities, typically via Trading Standards, enforce energy performance requirements and may fine occupiers who fail to provide a valid certificate or advisory report within seven days of a request.
How We Support You
We provide accurate, fully compliant Display Energy Certificates for public and commercial buildings in accordance with evolving UK regulations.
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DECs Completed
Our accredited assessors handle the full certification process, including on-site evaluation, lodgement, and the issuance of the certificate and advisory report.