How do you get an A rated EPC?

A rating scale

This guide explains how

Ever thought that seeing an A rated EPC is like seeing a mythical unicorn?

Well, A rated EPCs are rare but they are possibly to acheive. This guide will explain what it takes to get this top rating.

Understanding EPC ratings

An Energy Performance Certificate (EPC) is a document that provides information on the energy efficiency of a building. It shows how much energy is used and how much carbon dioxide is produced by the building and gives it a rating on a scale of A to G, with A being the most energy efficient and G being the least.

So what does it take to achieve an A rated EPC?

According to the government EPC register in the year 2022, there were 1,499,924 EPCs registered on existing dwellings. Only 0.18% achieved an EPC rating of an A.

The breakdown of the ratings of all these properties in 2022 were as follows.


So, you can see it is quite rare to achieve an A rating. As a company, we would only see around 1 to 2 properties a year that achieve the accolade of an EPC rating A.

The make-up of an A rated property

To start with, as mentioned in our previous article EPC rating B, all the thermal elements of the property will need to have high levels of insulation.

So, this means the

  • Floors
  • Walls
  • Roofs

The amount of insulation that you will need is often more than people think. It’s surprising how many properties we come across where only 25mm of internal wall insulation was added to the solid internal wall.

Unfortunately those kinds of level just isn’t going to hack it.

The EPC uses u-values to calculate the rate heat is lost through an element such as the roof.

A u-value is a calculation that determines the rate that heat is lost through the different types of construction elements that make up a structure such as a wall. The lower the u-value the more thermally efficient an element is.

To get anywhere near to an A rating these are the kinds of you values you will need to be achieving:

Walls: 0.30
Floors: 0.25
Roofs: 0.20
Windows: 1.60

Heating Requirements

Along with good insulation, the heating system needs to be very efficient. So, this means either a condensing boiler, of at least 89% efficiency or a heat pump of at least 300%.

Heating Controls

The property will also need to have time and temperature zone control where different parts of the property can be controlled independently.

Secondary Heating

Preferably there should be no secondary heating used, as this will lower the EPC rating. Room electric fires, and open chimneys are a no no and will hinder the property in attaining that top rating.

Main fuel cost

The EPC rating is based on the cost it needs to provide heating and hot water to the home.

Therefore, if you have an expensive source of fuel, then it’s extremely unlikely that you’ll get to an A rating. If your property is heated by LPG or on peak electric, then you’re not going to get there.

The impact of Solar Photovoltaic (PV) on the EPC rating

Even if you’ve you got all the thermal elements of the home to the standards previously mentioned, this is still only likely to get the property to a B rating.

You will need one final element to get it up to an A rating and that is Solar PV.

Improving the fabric elements of a home can only get you so far.

Solar pv can significantly reduce a properties energy running cost and therefore is an important factor in getting to an A.

Simply put, a property will have to have solar to get to an A, the larger the system the better will be the rating.

Stop guessing EPC rating



To achieve an A rated EPC is not easy to do. At this type of rating, the property will be achieving near zero carbon emissions which will mean low energy bills and low CO2 emissions.

All fabric elements will need to have excellent levels of insulation.

The heating system needs to have a high efficiency and full heating controls.

A reasonably sized solar pv system is also required to be present.

Certain properties that use an expensive form of fuel to heat the property are not going to achieve an A rating.

Documentary evidence should be kept of any improvements made that the EPC Assessor wouldn’t normally be able to see during a site visit. This typically applies to floors, sloping ceilings and flat roofs.

It is preferable that u-values are calculated by a suitably qualified assessor as opposed to using the software default values as this will normally have a better outcome.

A rated properties are usually achieved by design and working with a qualified and experienced assessor who can provide guidance in achieving your desired energy rating.

If you need any assistance on your project, get in touch with us at, [email protected], or call us on 0800 046 7345.


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Rickie Dickson
Written by Rickie Dickson

Rickie Dickson is an experienced and qualified domestic and non domestic energy assessor. He helps homeowners and businesses in all matters relating to energy efficiency, from meeting building regulations compliance to improving a property’s energy rating score.