Display Energy Certificates for London's Public Buildings
Fully accredited DEC assessors covering all London boroughs. Certificate, advisory report, and expert guidance on improving your building's operational energy performance.
- Since 2007
- ~7% UK Market Share
- 4.8/5 Trustpilot(1,700+ Reviews)
- Directly Employed Assessors
What Is a Display Energy Certificate?
A Display Energy Certificate (DEC) shows the actual energy performance of a public building based on how much energy it consumes in practice. Unlike a standard non-domestic EPC, which is based on the theoretical performance of the building’s fabric and systems, a DEC takes into account real energy consumption data from metered energy bills over a 12-month period.
DECs are required for public buildings in England and Wales that are:
- Occupied by a public authority or institution providing a public service
- Greater than 250m² in total useful floor area
- Frequently visited by the public
The DEC must be displayed in a prominent place that is clearly visible to the public visiting the building.
DEC Requirements
Certificate Validity
- Buildings over 1,000m²: renewed annually
- Buildings 250m²–1,000m²: renewed every 10 years
Advisory Report
All DECs must be accompanied by an advisory report with recommendations for improving energy efficiency. Valid for seven years.
Penalties
Failure to display a valid DEC can result in a penalty notice. Enforcement is carried out by local authority trading standards officers.
How the DEC Process Works
Data Collection
We'll need 12 months of energy consumption data — typically gas and electricity bills, plus basic information about the building's floor area and its use.
Site Survey
One of our accredited assessors visits the building to verify the floor area, assess the building's use category, and gather any additional information.
Calculation & Rating
Using the energy consumption data, we calculate the building's operational rating on an A to G scale, comparing against a benchmark for similar buildings.
Your Documents
You receive the DEC itself (for display) and the advisory report with recommendations for improving energy efficiency.
DEC vs EPC: What’s the Difference?
| DEC | EPC | |
|---|---|---|
| Based on | Actual energy consumption (bills) | Theoretical energy performance (building fabric & systems) |
| Required for | Public buildings over 250m² | All commercial properties being sold or let |
| Display | Must be displayed publicly | Must be available on request |
| Renewal | Annually (>1,000m²) or every 10 years | Every 10 years |
| Purpose | Shows actual performance | Shows inherent energy efficiency |
Some buildings require both a DEC and an EPC. If your public building is also being sold or let, you’ll need an EPC in addition to the DEC.
Who Needs a DEC in London?
Typical buildings that require DECs in London include:
If you’re unsure whether your building requires a DEC, our team can advise you based on the specific circumstances.
Get Your DEC Quote
Tell us about your building and we'll provide a clear, no-obligation quote.