Display Energy Certificates
and Non-Domestic Energy Certificates

Our team of energy engineers at BiU are qualified to carry out EPCs and DECs across the UK

Qualified energy assessor

Safe Contractor approved

Safe Contractor Approved

Recommended tangible energy savings


Commercial buildings, whether on sale, owned or leased, require legally to have a non-domestic EPC on display showing the energy performance and emissions of a property

What is an EPC/NDEPC?

An Energy Performance Certificate (EPC) rates a building between A to G, just like the fridge in your kitchen. With A being most efficient, and G least. The ND stands for non-domestic, such as buildings that are not used for domestic dwellings/homes such as supermarkets, museums, salons and hospitals.

But, unlike your fridge, the EPC for a building gives recommendations to improve efficiency for that building, and the rating the building could achieve if action was taken to improve it.

EPCs are a good starting point in your energy and carbon optimisation journey for a building or business. They provide recommendations for improvements, which will ultimately reduce your energy overheads, but also your carbon footprint.


Public buildings require to have a display energy certificate showing the consumption of power for the property

What is a DEC?

A Display Energy Certificate (DEC) focuses on the energy performance of a building, based on the consumption of gas and electricity annually.

This DEC rating provides the building with an operation rating, known as the building’s OR.

Public buildings require a DEC if they meet all three criteria below:

  • It is partially occupied by a public authority
  • It has a total floor area of over 250m2
  • It is frequently visited by the public

For instance, most councils, large libraries, leisure centres, colleges and NHS trusts would meet this criteria.

Each DEC will produce an advisory report (AR) basically stating the saving opportunities. For buildings with a floor area greater than 1000m2, the DEC is currently valid for one year and the AR for up to seven years. Below that and above 250m2 both DEC and AR are valid for the ten years


EPCs calculate the carbon emissions of a building, equipment, specifications and so on, where a DEC calculates the carbon emissions based only on the utility bills and energy system in place.

EPCs measure the efficiency of the building design and DECs measure how efficiently the building is being used in operation.

How can BiU help with DEC and EPCs?

We have a suite of BiU Energy Engineers within our energy and carbon optimisation team who are qualified to carry our DEC and EPC audits and ultimately issue certifications and recommendations.

More than an energy certificate!

Our energy and carbon optimisation team work with on-site maintenance and building supervisors and technicians, as well as utilise our team of qualified energy engineers.

Our BiU energy engineers can carry out submetering, equipment upgrades and changes, as well as a range of energy optimisation projects directly. Furthermore, we have long-standing partnerships for larger projects such as Building Energy Management Systems (BEMS) and retrofit upgrades to equipment.

Safe contractor approved, branded BiU, and carrying ID for trust and clarity

Smart and professional to be on-site, while customers are on-site

Supported by a team of data scientists to examine findings effectively

DEC and EPC Frequently Asked Questions

Yes. If you want to sell or let a commercial property, you will need to have a valid EPC before the property is on the market.

Other than the direct power and gas costs related to the business to heat/cool and so on, you may find you can’t attract as virtuous businesses to rent or buy the property. With net zero and carbon compliance becoming more prevalent for businesses, a well performing business property is essential.

From the 1st April 2018, new Minimum Energy Efficient Standards (MEES) came into force. These changes make it unlawful to lease a commercial property with an Energy Performance Certificate (EPC) rating below an E. It is advised to action on the recommendations from the EPC to improve the rating above this level.

This depends on the status of your building and purpose. Some exemptions include:

  • Temporary buildings only going to be used for a maximum of 2 years
  • Places of worship or regular religious activities
  • Unheated industrial sites, workshop buildings or non-residential agricultural buildings
  • Detached buildings with a total floor space under 50m2
  • If a building has consent to be demolished


  • A DEC will last for 1 year when a building has a total useful floor area more than 1,000m2
  • A DEC will last for 10 years when a building has a total useful floor area over 250m2 up to 1,000m2


A building’s EPC lasts for 10 years. We recommend a new EPC if you have completed works on the building to improve its efficiency.



EPCs: For non-domestic properties, the penalty is a sum equivalent to 12.5% of the rateable value of the building, subject to a minimum of £500 and a maximum of £5,000. If they can’t apply this rate the default penalty is £750, per property.

DECs: A local authority can issue a penalty charge notice of £500 for failing to display a DEC at all times in a place clearly visible, and further fines such as £1,000 for failing to possess or have in their control a valid report.

From 2020 you can’t create a new or renew existing tenancy in a building if your building holds an EPC rating of F and below (G, H and so on). This affects over a million buildings in the UK and could face fines if action isn’t taken to make them more energy-efficient. If a landlord has a building with a ‘poor’ EPC of F and below, a potential fine of £5,000 per property which are found in breach of the legislation.

Surprisingly, some organisations don’t realise that since 2008 all large public buildings required an annual Display Energy Certificate (DEC) which highlights their energy performance, and to be displayed in an easy-to-view location for visitors.

Where next


Learn more about how our energy and optimisation team can help manage your compliance obligations, reduce carbon and create lasting behavioural change in staff with a suite of our services.

Get in touch

Head of Utility Management Solutions

Get in touch with us on 01253 789816 or email our Director of Energy Management, Angela, on utilityteam@biu.com