Display Energy Certificates Guide Summary
Display Energy Certificates (DECs) provide a transparent, easy‑to‑understand view of how efficiently a public building uses energy. They are designed to give members of the public clear insight into the performance of the buildings they visit, helping raise awareness of energy consumption and encouraging organisations to improve energy efficiency.
DECs are a legal requirement for many public buildings and play an important role in supporting compliance, operational efficiency and carbon reduction.
In England and Wales, the legal requirements for Display Energy Certificates are set out in government guidance on Display Energy Certificates and advisory reports for public buildings.
What a Display Energy Certificate is
A DEC rates the actual operational energy performance of a building using a scale from A (most efficient) to G (least efficient).
Unlike EPCs, which are based on theoretical building fabric performance, DECs measure real‑world energy consumption using metered data from the past 12 months. They must be accompanied by a Recommendation Report, which provides actionable suggestions for improving energy performance.
Recommendation Report validity
- Buildings over 1000 m² → valid for 7 years
- Buildings 250–1000 m² → valid for 10 years.
Which Organisations Require a DEC
DECs are required for buildings that:
- Are occupied by public authorities
- Are frequently visited by the public
- Have a total useful floor area over 250 m².
Examples include:
- NHS Trusts, hospitals, healthcare centres
- Schools, universities and higher‑education buildings
- Leisure centres, public libraries, museums and galleries
- Police stations, courts and prisons.
These requirements are part of the Energy Performance of Buildings Regulations, aimed at improving transparency and energy performance in public buildings.
Who is Responsible for Displaying the DEC?
The building occupier must ensure the DEC is displayed prominently and accompanied by a valid Recommendation Report.
What do you need for a DEC quote?
- Total floor area
- Number of buildings
- Whether you need a DEC, Recommendation Report, or both.
What Buildings are Exempt?
External government guidance notes exemptions for buildings such as:
- Places of worship
- Temporary buildings (≤2 years)
- Certain industrial buildings with low energy demand.
The DEC Process
Step 1 – Data collection
Gather energy consumption data for the previous 12 months (electricity, gas, fuels), along with building size, operational hours and occupancy information.
Step 2 – Assessment
An accredited assessor reviews metered data, benchmarks performance and inspects the building to determine the DEC rating.
Step 3 – Issuing and displaying the DEC
A DEC is produced with the A–G operational rating and must be displayed where the public can clearly see it.
Reviewing a Display Energy Certificate example can help illustrate how operational ratings change over time and how performance is presented.
Advisory Report
Includes tailored opportunities such as:
- Lighting upgrades
- BMS and controls optimisation
- Insulation or heating efficiency improvements.
Although not mandatory to act on, implementing measures can deliver substantial savings.
Benefits of DECs
DECs deliver several advantages for public organisations:
- Transparency – improves public awareness of building performance
- Cost savings – identifies opportunities to reduce operating costs
- Operational efficiency – reveals system inefficiencies
- Environmental impact – reduces energy use and emissions
- Regulatory compliance – avoids penalties and strengthens governance.
Additional internal insights show DECs are an effective gateway to broader energy management improvements.
Penalties for Non‑compliance
Failure to display a valid DEC or hold an up‑to‑date Recommendation Report can lead to fines of up to £1,500.
Public bodies must ensure ongoing compliance, especially as regulations evolve alongside wider EPC/EPB reforms.
Summary
Display Energy Certificates are a practical and legally required tool for improving transparency and driving better energy performance in public buildings. By measuring real energy use, DECs provide building managers with meaningful insight to reduce consumption, improve efficiency and support long‑term sustainability goals.
Implementing and maintaining DECs ensures compliance, supports carbon reduction and helps public organisations demonstrate leadership in environmental performance.
Learn more about DEC assessments here: Display Energy Certificates (DEC)
Written by Giles Davies – Energy Consultant, ABBE DipOR(QCF), PBEA, AMEI
Giles focuses on DECs, compliance support and site surveys, connecting legislation with practical building performance improvements.