DEC (DISPLAY ENERGY CERTIFICATION)
Display Energy Certificates (DECs) are mandatory for buildings over 250m² that are occupied by public authorities and frequently accessed by the public. These certificates must be clearly displayed in a prominent location within the building.
The validity period for DECs depends on the size of the building:
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Buildings between 250m² and 1,000m² – valid for 10 years
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Buildings over 1,000m² – valid for 1 year
DECs reflect the actual operational energy performance of a building and compare it against similar buildings through a benchmarking system. Each building is rated on a scale from A to G, with ‘A’ being the most efficient.
Typical buildings that require a DEC include:
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Hospitals
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Libraries
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Public leisure centres
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Schools
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Tax offices
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Universities
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Charitable organisations that receive public funding and are regularly accessed by the public
Alongside the DEC, an Advisory Report must also be provided. This report outlines practical recommendations for improving the building’s energy performance.
The DEC regulations are currently under government review, with an announcement expected in 2026. Updates may affect validity periods, thresholds, or performance criteria.