Energy Performance Certificates (EPCs) explained

11 November 2020 Kingspan Insulation UK

When a home is built, sold or rented in the UK it is mandatory that an Energy Performance Certificate (EPC) is created. This is essentially a report card grading how well the property uses energy under standardised conditions and which identifies some areas for improvement of the rating. This certificate offers a useful guide to the current performance of a home and offers a starting point for suggestions of what improvements you can make to your property and how much money you could save by implementing them. 

What is an Energy Performance Certificate (EPC)?

The EPC provides an ‘asset rating’ of the energy cost and carbon emissions of a home in standardised conditions. Unlike an ‘operational rating’, where the actual energy used by occupants is monitored, the ‘asset rating’ simply models the theoretical energy efficiency of the building based on a few factors such as how well insulated it is and how efficient your boiler is.

There are some differences between how a new home, or an existing home are assessed, but broadly speaking, EPCs consider various aspects of the property, including the performance of your heating system and its controls, hot water demands, lighting, ventilation, and what type of windows and doors you have as well as how well insulated your property is. For existing homes, various assumptions can be made based on the age of the property and what is known about it. This data is inputted into software which uses the Standard Assessment Procedure (SAP) to calculate an energy cost rating (SAP score) and an environmental impact rating for your home. The EPC certificate is not itself a retrofit assessment or plan, such as that recommended under PAS2035, but it does give some potential improvement options for energy efficiency.


How can I find my home’s Energy Performance Certificate?

If your home has an EPC you will typically be able to download it by entering your address here.


How can I arrange to have an EPC carried out?

If you can’t see an EPC on the energy register and you are thinking of making energy improvements to your property, then it is a good idea to get one carried out. You can find accredited Energy Assessors to carry out this work here

Once completed, the EPC will be valid for 10 years although you should update it if you decide to sell the property after improvements have been made.


What does an EPC energy efficiency rating mean?

The energy efficiency rating for your home is shown on page 1 of your EPC. This is given on a scale from A to G with A being the most energy efficient classification. As shown in the table below, most homes in England achieve a rating of D with older properties typically performing worse, meaning they will cost more to run.
Rating Number of homes Percentage
A/B 321,000 1.3%
C 7,969,000 33.0%
D 11,909,000 49.3%
E 2,936,000 12.1%
F 832,000 3.4%
G 206,000 0.9%
Table 1 - EPC rating of homes in English Housing Survey 

To better understand your home’s current rating, take a look further into the report where there will be a summary of your home’s “energy performance related features”. Each feature (windows, heating, lighting etc.) is given a rating either using stars (from zero to five stars) or a worded rating from Very Poor to Very Good.


Can you fail an EPC assessment?

No, it is not possible to fail an EPC assessment. However, landlords should be aware that under the Minimum Energy Efficiency Standards (MEES) it is now a legal requirement for all privately rented properties to achieve a minimum EPC of E (subject to certain exceptions). Failure to meet these requirements can lead to considerable fines.
Learn more about MEES.


How much can I save by improving my home’s EPC rating?

In addition to providing a rating for your home’s energy performance, the EPC also offers an estimate of its potential performance. This is shown in the third column of the Energy Efficiency Rating graphic. This rating is based on a series of recommended measures for your home shown later on in the report. 

You will also be able to see a table on page 1 of the report with the “Estimate Energy Cost” for your property. This shows how much money and energy you could save over the next three years by implementing all of the report’s recommendations (in older reports this is given over a single year). 


How much will it cost to carry out the EPC recommendations?

The recommendations table within your EPC report should provide a clear breakdown of the indicative cost for installing any measures along with an estimate of how much you can save each year by having them implemented. It should be noted however, that this cost is for a ‘typical’ installation, not specifically for your home.


Do I need to follow the EPC recommendations in any order?

The recommendations table in your EPC has been ordered with the improvements which are expected to make the biggest difference at the top and the lowest at the bottom. The last column in the table shows how your EPC will improve if the measures are introduced in the order shown. 

It is by no means compulsory to introduce improvements in this order, however, you should keep in mind that improvements to the walls, roof and floor of your property – such as installing insulation, double or triple glazing and draught proofing – will impact how powerful your boiler/heat pump and radiators need to be. By implementing these first, you may therefore be able to fit smaller, more economical units in future.

It should also be noted, that whilst an EPC can help to inform an assessment of a property for the purposes of retrofit and for the development of a retrofit improvement plan, the recommendations, potential improvement level and costs given in the EPC are only indicative and the improvements suggested may not always be appropriate for a particular dwelling.

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