Display Energy Certificates (DECs)

Meet regulatory requirements and improve the energy efficiency of your buildings

We all have a responsibility to reduce our energy use. Our Display Energy Certificates (DEC) service ensures public bodies meet your regulatory obligations while helping to identify opportunities to reduce energy consumption, lower costs and minimise your carbon footprint.

A DEC provides an energy efficiency rating of a building based on the actual amount of metered energy used, measured on a scale of A to G, where A is very efficient and G is the least efficient. Our DECs offer a clear and transparent way to understand how efficiently your building is operating in practice.

  • Understand the energy efficiency of your building(s)

  • Avoid fines for non-compliance

  • Learn how to improve energy efficiency

  • Demonstrate environmental responsibility

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Understand your obligations and stay compliant

Requirements, compliance and benefits

Understanding when a DEC is required and how often it must be renewed will help you maintain compliance, avoid penalties and ensure your buildings continue to operate efficiently.

A valid Display Energy Certificate (DEC) and Recommendation Report are legally required for every publicly funded building over 250m² that is frequently visited by the public.
For buildings over 1,000m², a DEC certificate is required annually, and the Recommendation Report must be renewed every seven years.

For buildings between 250m² and 999m², Display Energy Certificates and Recommendation Reports are required every 10 years. These requirements apply to a wide range of public buildings, including schools, local authority buildings, leisure centres and other publicly accessible facilities. Ensuring your DECs are accurate, valid and up to date is essential for maintaining compliance and demonstrating responsible building management.

Fines of up to £1,000 can be levied for non-compliance, but the risks extend beyond financial penalties. Failure to maintain valid Display Energy Certificates can lead to increased scrutiny, reputational damage and missed opportunities to improve building performance.

By taking a proactive approach, organisations can avoid disruption, reduce compliance risk and ensure that their DECs support both regulatory requirements and wider operational goals.

A DEC reflects how a building performs in real operational conditions, based on actual energy consumption rather than design estimates. This makes Display Energy Certificates particularly valuable for organisations that want to understand and improve how their buildings are used day-to-day.

Each certificate is accompanied by a Recommendation Report, which outlines practical steps to improve energy efficiency. These insights allow you to prioritise actions that can deliver measurable improvements in performance, cost and carbon reduction.

Key features and benefits

Meet your regulatory obligations

To avoid fines and ensure compliance, organisations must display their Display Energy Certificates in a prominent location clearly visible to the public, while also maintaining a valid Recommendation Report. Our service ensures your DECs meet all current UK regulatory requirements and are delivered efficiently and accurately.

Improve energy efficiency in your buildings

The Recommendation Report linked to your DEC highlights opportunities to improve performance. By acting on these insights, you can reduce energy waste, optimise building performance and achieve better long-term efficiency outcomes.

Market-leading service

We are committed to supporting customers with effective energy management through high-quality Display Energy Certificates. Our market-leading service has earned us a reputation as one of the UK’s leading providers, delivering approximately 10% of all DECs nationwide. This scale gives our clients confidence in both our expertise and our ability to deliver consistently.

Reduce energy, costs and your carbon footprint

Reducing the use of lighting, heating, cooling and other energy-consuming equipment is essential for both cost control and sustainability. Our Display Energy Certificates service helps you understand your building performance in detail, enabling you to take informed action to reduce energy use, lower operational costs and minimise environmental impact.

Why choose Zenergi for your Display Energy Certificates?

Organisations choose Zenergi for expert support that goes beyond certification, ensuring efficient compliance while delivering meaningful performance improvements.

Our teams combine technical expertise, data insight and practical experience across a wide range of public sector environments. We understand the operational challenges faced by organisations managing multiple buildings and complex estates, and we tailor our Display Energy Certificates service to meet those needs.

By choosing Zenergi, you benefit from an energy partner with proven experience delivering DECs for a variety of organisations, a structured and reliable approach to compliance, clear and actionable insights to improve building performance, and support that aligns compliance with wider energy and carbon reduction objectives.

This ensures your Display Energy Certificates are not just a regulatory requirement, but a valuable tool for improving how your buildings operate.

Simple, end-to-end support for compliance

How we support you

Our approach is designed to make compliance straightforward and efficient while minimising disruption to your organisation. We assess your buildings and gather the required energy data to produce accurate and compliant DEC outputs, alongside Recommendation Reports that provide clear, practical guidance, ensuring you fully understand your results and next steps.

Our experts help you meet obligations and improve building performance through Display Energy Certificates.

Speak to an expert today or book your DEC assessment to ensure your compliance is up to date.

Learn more

Our experience

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ESOS audit identifies £4 million in cost savings.

Explore how our ESOS Phase 3 audit uncovered a 5% energy reduction and a two-year ROI for a FTSE 250 food and drink manufacturer.

Energy reduction
33,093 MWh
Cost savings
£4.1 million
Carbon reduction
6,219
tCO2e

Uncovering potential energy savings of 26% for East Sussex County Council

Discover how we identified potential annual savings of more than £52,000 for a progressive Local Authority with ambitious net zero targets

Identified energy savings
1,042,371 kWh
Identified cost savings
£52,567
Identified carbon savings
194
tCO2e

Annual saving of £61,000+ and immediate ROI from TM44 A/C Inspection.

Discover how a global data centre accessed major operational savings and maintained compliance.

Saving from cleaning the chillers
£
40,000+
Saving from adjusting the schedules
£
21,000+
Saving from upgrading the chillers
£
337,000+

Unlocking £5 million in savings with ESOS compliance

How a global renewable energy leader turned ESOS into a strategic opportunity for efficiency and sustainability.

Energy savings
26,000,000 kWh
Carbon reduction
8,300 tCO₂e
Cost savings
£4.91 million

Powering a historic dining hall for St John’s School.

Our Siteworks team streamlined a complex meter installation to meet ambitious timescales and ensure a new dining hall opened on time.

Karina Joshi

Strategic Customer Success Manager

St John's School Customer Success Manager

How our energy audit identified savings of £50,000 for E-ACT.

Discover how our exciting new programme for Multi-Academy Trust, E-ACT, identified huge carbon and cost savings in just six months.

Identified energy savings
246,193
kWh
Identified carbon savings
48.16
tCO2e
Identified cost savings
£
50,114

Greener transport: helping Gregory Group meet ambitious goals.

A science-led partnership with one of the UK’s largest transport groups that led to impressive net zero acceleration.

Harry Eaves

Senior Energy Consultant

Zenergi

Halving Glenmorangie’s energy costs through strategic building optimisation.

Discover how our partnership helped a whisky giant transform their facility’s energy efficiency with targeted solutions.

Estimated annual electricity consumption savings
59
%
Estimated annual gas consumption savings
52
%
Estimated annual overall energy savings
55
%
How we helped Danes Educational Trust unlock £166,000 for carbon reduction.

How we helped Danes Educational Trust secure £166,000 for carbon reduction.

Phase 2 LCSF grant awarded
£
39,000

Partnering with PR Associates to drive compliance and energy efficiency in schools.

We’re helping to ensure over 100 schools have the confidence to focus on their priorities – all while remaining compliant and optimising efficiency.

Simon Watts

Partnerships Manager

Zenergi

Shropshire Council: Enabling compliance for over 10 years.

We’re helping Shropshire Council to achieve compliance through Display Energy Certificates and progressively reduce its environmental footprint. Zenergi is also enabling targeted energy reduction in key buildings.

Darren Myers

Carbon Compliance Manager

Zenergi

Future-proofing Reading Borough Council’s commercial properties to comply with 2030 energy efficiency targets.

We’re ensuring the council’s buildings comply with the Minimum Energy Efficiency Standard and working together to deliver a clear pathway to 2030.

John Netherwood

Chief Operations Officer

Zenergi

A state-of-the-art, energy-efficient health centre for Henley Green.

Discover how our partnership transformed this Coventry practice into a model of healthcare sustainability and wellbeing-centred design.

Zahid Khalifa

Principal Electrical Design Engineer

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FAQs

A DEC certificate is a document that shows the energy performance of a building based on actual usage. Display Energy Certificates provide an energy efficiency rating from A to G and are required for public buildings over a certain size that are visited by the public.

The organisation occupying or managing the building is responsible for ensuring valid DECs are in place and displayed correctly.

Renewal depends on building size. Buildings between 250m² and 999m², need a Display Energy Certificates and Recommendation Report every 10 years.
Buildings over 1,000m², require a DEC certificate annually, and the Recommendation Report must be renewed every seven years.

The Recommendation Report provides guidance on how to improve the energy efficiency of your building following your Display Energy Certificates assessment.

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