Read DEC and EPC ratings as different evidence
A facilities team may find that its operational rating and asset rating tell different stories. That is a reason to investigate the inputs, rather than assuming a certificate must be wrong. The GOV.UK DEC guide describes a rating based on actual consumption. Energy management decisions therefore sit much closer to the DEC evidence than they do to a standardised asset assessment.
For example, extended opening hours, changes in activities and equipment use can help explain consumption patterns. Keep an account of such changes alongside the meter records. The assessor can then consider the evidence within the methodology instead of trying to infer building use from unexplained bills. Do not edit out inconvenient consumption simply to make the result look better.
An EPC is useful for a different discussion about the building and its systems. The GOV.UK commercial EPC guidance covers its role and the recommendations provided. Treat those recommendations as a starting point for feasibility work, rather than a measured prediction of what your organisation will spend after each improvement.
Check DEC and EPC triggers separately
A building being open to customers does not by itself establish the public-authority occupation test described in the GOV.UK DEC guide. Identify who occupies the building, how the public uses it and the relevant floor area. A building name such as community centre is insufficient evidence of the legal position.
For a sale or new letting, examine the EPC question independently using GOV.UK commercial EPC guidance. An existing displayed operational certificate should not be offered to an agent as a replacement. Equally, receiving an EPC for a property transaction does not settle the occupying authority's separate DEC responsibilities under the GOV.UK DEC guide.
If homes form part of the property, use the relevant GOV.UK domestic EPC guidance for that question. A mixed estate may need several assessment scopes rather than a single instruction covering everything at the address. Our EPC cost guide explains why the assessment type affects the quote.
Our Display Energy Certificate service can help establish the operational assessment scope. Compare the evidence below before asking for a certificate simply described as an energy rating.
| Issue | Display Energy Certificate | Energy Performance Certificate |
|---|---|---|
| Main question | How does the building perform in operation, based on recorded energy consumption? | How does the building perform under the applicable standard assessment assumptions? |
| Main evidence | Energy consumption records, floor area, building use and relevant operational information. | Construction and building-services evidence used in the applicable energy assessment. |
| Typical trigger | Qualifying occupation by a public authority with public access and the applicable floor-area test. | Relevant sale, letting or completion of a building, subject to the guidance and exemptions. |
| Main audience | The occupying authority, building users and visitors who see the displayed certificate. | Prospective purchasers, tenants and others needing the property energy assessment. |
| Improvement document | An advisory report accompanies the operational assessment. | Recommendations accompany the certificate and relate to improving building performance. |
| Can it substitute? | It does not replace an EPC where an EPC is required. | It does not satisfy a separate duty to obtain and display a DEC. |
(Source: GOV.UK DEC guide; GOV.UK commercial EPC guidance)
Resolve shared meters before commissioning a DEC
Start with a plan showing building boundaries and the meters serving them. List electricity, gas and any other supplied fuels, then identify which records correspond to each meter. Mark shared supplies, estimated readings and gaps. This gives the assessor a useful evidence map without presuming that every bill belongs wholly to the building being assessed.
On a campus, a single incoming supply may serve spaces with different uses or occupiers. Explain any submetering and the basis of internal allocations. An accounts spreadsheet showing a cost split is different from a consumption record. Ask the assessor what further evidence is needed before treating a financial allocation as assessment data.
Keep a named contact for queries about the records and another for building access if those responsibilities differ. The facilities manager support page is relevant when the certificate commission forms part of a wider estate review. Our landlord compliance checklist covers a different set of property-management questions and should not be used to determine DEC eligibility.
Specify the DEC and EPC deliverables before instruction
Request a written scope identifying the building or parts assessed, certificate type, evidence required and any accompanying report. For an operational assessment, ask how unresolved meter boundaries will be dealt with. For an asset assessment, explain whether the building has changed since the last certificate and make the available construction and services records accessible.
You can look for existing records through GOV.UK Find an energy certificate, then send the relevant references to our Display Energy Certificate service. Include the occupier details, building-use description and meter schedule. If an EPC is also needed, identify that as a separate output so neither requirement disappears within an ambiguous instruction.
About our Display Energy Certificates service
For the service itself, see Display Energy Certificates.