The History of the Energy Performance Certificate

If you’ve moved or recently rented a property in the UK – either domestic or commercial – you will have heard of an Energy Performance Certificate (EPC).

Energy Performance Certificates were introduced by the government in an attempt to make people become more aware of the energy that a building uses. They also help potential buyers or tenants have an idea of how energy efficient the property is (also effecting their energy bills). An EPC also helps to make a building more energy efficient by giving them recommendations of improvement.

They are issued in the UK by our EPC London or EPC Glasgow team when the occupation of a building changes and are issued as a result of an inspection by an accredited assessor to give the new occupants a detailed understanding of the energy performance of the building at that time.

In the Beginning…

EPC’s were first introduced by the UK government on 1st August 2007 in England and Wales. They were introduced due to the requirements of the EU Directive on the energy performance of buildings and were to be part of the Home Information Pack (HIP), which was supplied by people who were selling properties with four bedrooms or more.

The requirements to have an EPC when a building was being sold or rented were then gradually extended to all buildings, both domestic and commercial.

The government changed the legal requirement of a HIP in May 2010, but the need to provide an EPC remained and it is still an important aspect of selling or renting a building today.

EPC’s Today

Today, there are three kinds of EPC – a Domestic EPC, a Commercial EPC and a Display Energy Certificate – also known as a DEC.

  • Domestic Energy Certificate is required when a building – which is the dwelling of one family – is sold or rented, regardless of the size. Therefore, if you are either selling or renting out your property, you will need to provide an EPC.

There are, however, some exceptions, which include; temporary buildings that won’t be used for more than two years, stand-alone buildings with a total floor space of less than 50m², workshops and non-residential sites which use little energy, holiday accommodation or residential buildings which are let out for four months or less per year, and some listed buildings.

If a domestic property does not have an EPC when it is being sold or rented out, a fine of £200 is applicable.

  • Commercial Energy Certificate is required if you are selling or leasing a commercial property. They are also required if you’ve recently had construction done on your property, which you must have completed before the property is advertised.

Some of the exceptions for not needing a Commercial EPC include: if it is a place of worship, temporary structures which will not be used for more than two years, stand-alone buildings with a total floor space of less than 50m², properties which already have a demolition order in place, properties with a low demand for energy such as agricultural buildings.

A commercial building which does not have an EPC when it is required could be fined between £500 and £5000.

  • Display Energy Certificate is required by public buildings and must be displayed to advise the public who are using the building of its energy efficiency. By law it must be placed in a prominent place – often by the reception or near the main entrance – and the failure to do this can result in a £500 fine.

The law says that you need to have a DEC if you meet three criteria – that:

  • the building is partly or fully occupied by a public authority – such as a leisure centre, the NHS, a college, council premises, or museum
  • it has a total floor area of over 250m²
  • it is regularly visited by members of the public (regardless of how many people actually turn up)

In addition to this, if the total useful floor area is over 1000m², you should renew the DEC every year. If the total floor area is between 250m²and 1000m², the certificate would be valid for ten years.


A DEC, which is displayed in public buildings is slightly different from an EPC, as it tells people publicly about the actual energy use of the building. Again, an A to G rating is given, but it is calculated using energy bills over the last two years and is then compared to other buildings of a similar type.

It gives people who use the building the opportunity to see how energy efficient it is, and also comes with energy efficiency recommendations for the owner.

What Does an EPC Tell You?

Part 1 – Information

The short answer to this question is that it would tell you all about the energy efficiency of your property – or the one that you are looking to buy or rent.

Your EPC will usually be split into four sections – the first one giving you the details of the property as well as some of the property’s energy use stats. The second gives an easy to read energy efficiency rating. Thirdly, information about who the energy performance could be improved in that particular building, and finally a summary of the factors that go towards the rating in terms of energy efficiency.

In this part, information about the property, in general, is displayed as well as information about its energy efficiency

It will show the address and property type, as well as the date of assessment and reference number, the type of assessment and the total floor area of the building.

It then goes on to tell you how much the energy costs of an average household would be for a building of the same type. This enables you to get an idea of what the energy costs should be for the property, as well as letting you compare your property (or potential property) with others which are similar.

Part 2 – The Energy Efficiency Rating

This is the part of the EPC which would be most noticeable. It is where you can get – at a glance – a general grasp of how energy efficient the building is.

The building is given a rating of between A and G, with ‘A’ being very energy efficient, and ‘G’ extremely inefficient, which is then shown on the graphic – with ‘A’ being at the top. This gives the reader an automatic and extremely visual depiction of the energy rating. The graphic also shows what the potential for the building is if the recommendations made are carried out.

In addition to the Energy Efficiency Rating, the EPC will also give you an Environmental Impact CO2 rating which displays the information in a similar way and on the same scale. You will get both a current and potential rating which indicates the total impact of the building on the environment in terms of Carbon Dioxide emissions.

The energy efficiency rating is calculated based on a number of different criteria, including the efficiency of heating and lighting systems, the age of the building, as well as insulation of windows, lofts and walls. This information is collected when an assessor comes to the building.

It is the Building Research Establishment who is responsible for setting out the guidelines to the assessors which help them to calculate the overall rating. They use a predetermined SAP (Standard Assessment Procedure) to find the rating. SAP was developed for the government at the BRE in 1992 to help them to standardise and measure the Department of the Environment’s policies with regards to energy efficiency.

The SAP guidelines are subject to change, and currently, assessors are using the 2012 amendments to SAP. This does mean, however, that there is a possibility that if a property is assessed by two different ‘versions’ of SAP, the energy efficiency rating could go down.

Part 3 – Top Actions and Recommendations

In the third section, the EPC will set out some recommendations from the assessor as to what could be done to the building to improve its energy rating. It is these recommendations that the ‘potential’ ratings are made with. By carrying out some of all of these recommendations, the building will not only be more energy-efficient, but the cost of energy bills will also be reduced.

These measures will usually include getting new and more energy efficient boilers, loft and wall or floor insulation, getting double glazing, or using new technology as it becomes available.

Of the recommendations which are made, the assessor will also indicate whether there is a possibility that the energy-saving measure could be eligible for finance from the Green Deal. If the tick is ‘green’, it could be eligible for the complete financing of the measure, and when it is orange it could be eligible for part financing.

Part 4 – Summary of Property Features

In the final section, the features of the property are broken down and most of them given their own energy efficiency rating according to their u-values. These elements include lighting, heating and water and structural features like walls, roof and floor.

Managing energy and waste energy requires that you understand where your energy is being wasted and where polluting forms of waste are occurring. This is why EPC’s and DEC’s are so important and are as important today as they were when they were introduced back in 2007.

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Nexus Energy Solutions offer impartial and cost-effective renewable energy advice to SMEs, large enterprises and local Governments. A commercial or domestic EPC will highlight areas for energy improvement in your organisation and offer an alternative approach to your traditional energy management process.

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