EPC rating (Energy Performance Certificate)

An EPC rating section of an EPC. The ratings go from G (red) to A (green)

What is an EPC rating?

An EPC (Energy Performance Certificate) rating tells you how energy efficient a property is.

This gives you a good idea of what the energy costs for that property would be. The EPC rating goes from A (very efficient; low running costs) to G (very inefficient; high running costs).

EPC ratings work a lot like exam grades. An EPC assessor looks at how energy efficient different parts of your home are. This includes your heating system, your walls, and even your light bulbs.

The EPC assessor then calculates a score out of 100. This is known as the Standard Assessment Procedure (SAP) score. Using the SAP score, the assessor works out the EPC rating.

You’ll find your home’s EPC rating on its Energy Performance Certificate (EPC).

How is an EPC rating worked out?

There are two methods for working out a home’s energy performance:

  • The Standard Assessment Procedure (SAP)
  • The reduced data Standard Assessment Procedure (rdSAP)

SAP and rdSAP scores

Both these methods involve a specialist assessing your home, then making calculations to come up with a score. The major difference between them is the amount of information that the assessor can access.

With the SAP, the assessor looks at architectural plans and other construction documents.

On the other hand, with an rdSAP, the assessor doesn’t have access to these documents. Instead, they visit the property and make calculation based on what they can see.

The SAP method is used for new dwellings, whereas the rdSAP method is used for existing dwellings.

You can find out more in-depth information about SAP and rdSAP on the gov.uk website.

What are the different EPC ratings? 

An assessor will work out a SAP or rdSAP score for your property. The score will be out of 100, with 100 being the most energy efficient. The SAP/rdSAP score will determine the EPC rating.

EPC ratingSAP or rdSAP score
A92 – 100
B81 – 91
C69 – 80
D55 – 68
E39 – 54
F21 – 38
G1 – 20

For example, if your SAP/rdSAP score is 71, then your EPC rating is C.  If your SAP/rdSAP score is 25, then your EPC rating is F. 

What is energy efficiency? 

Our Energy Performance Certificate rating tells us how energy efficient our homes are, but what does energy efficiency actually mean? 

At its simplest, energy efficiency means getting the result we want by using as little energy as possible.   

Let’s take heating our home as an example. The result we want is a warm home. An energy efficient system would be one where we can get a warm home using as little energy as possible.  

A good example of an inefficient system would be a wall that doesn’t have any insulation. We use energy to run our heating. Without insulation, a lot of that heat is lost through the wall. This means we have to use more energy to replace the lost heat. 

A good example of an efficient system would be an air source heat pump. You don’t need to put much electricity into a heat pump to get a lot of heat out. Every kilowatt (kW) of electricity you put in gives you 3kW of heat.   

How to improve your EPC rating 

Improving your EPC rating means making changes to your home’s insulation and/or heating system. What changes you make depend on what you already have in place.

For example:  

  • You may already have loft insulation but no wall insulation 
  • You may have a gas boiler, but it may be old and inefficient    

If you already have an Energy Performance Certificate, it will tell you how to improve your rating. You’ll find a ‘Recommendations for Improvement’ section on page two. Your EPC lists the improvements in order of importance. The ones at the top of the list will make the biggest difference to your rating. 

The ‘Recommendations for Improvement’ section also tells you what rating you’ll reach by making the suggested changes:

A table showing the recomended measures to install at the property. It also shows the cost, savings and impact the measure will have on the EPC rating

In this example, installing internal or external wall insulation will raise the rating to C77.

If you don’t already have an Energy Performance Certificate, you can find out how to improve your EPC rating by: 

  • Speaking to Home Energy Scotland. Their advisors will help you work out what changes will make your home more energy efficient. You can call them for free on 0808 808 2282. You can also contact them through their online form. 
  • Getting an EPC. See the How to get an energy performance certificate section below.  

Energy Performance Certificate FAQs

Your home may already have an Energy Performance Certificate. Checking for this first can avoid the cost of getting a new certificate. An EPC should be part of the Home Report you receive when you move into a property.  

You may also be able to view your Energy Performance Certificate online. Visit the Scottish EPC register website to search via your postcode. 

If you don’t have an EPC, you can arrange for an assessor to produce one for your property. The Scottish EPC register lets you search for an assessor by location.

Energy Performance Certificate costs vary, depending on the size and type of your property. EPC prices usually range from £60 to £120.  

We would advise contacting at least three different assessors for quotes. Remember, you can search for assessors using the Scottish EPC register website.

An EPC is valid for ten years. When it runs out, you’ll need a new one if:

  • You’re selling your home
  • You’re renting the property to a new tenant

It’s also a good idea to get a new EPC after you’ve made any energy efficiency improvements to your home. When selling or renting your property, a new EPC gives potential buyers or renters the most up-to-date information.

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Home Energy Scotland logo

Changeworks delivers Home Energy Scotland in the south east and Highlands and Islands on behalf of the Scottish Government and Energy Saving Trust.

As well as providing free, impartial expert advice to thousands of people every month to help them to keep warm in their homes for less, they identify funding opportunities for households seeking to install energy efficiency measures.

For more information, give Home Energy Scotland a call on 0808 808 2282 or email and the team will be happy to help you.