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Thermal image shows the heat loss from a house
Thermal imaging shows the heat loss from a house, but EPC details of why, and how to fix, can be misleading. Photograph: Construction Photography/Alamy
Thermal imaging shows the heat loss from a house, but EPC details of why, and how to fix, can be misleading. Photograph: Construction Photography/Alamy

Are energy performance certificates worth the paper they’re written on?

This article is more than 2 months old

EPCs are meant to be a vital insight into how energy efficient a property is. But many are out of date and can be misleading

Most UK homes have one, and they are supposed to provide a vital insight into how energy-efficient a property is. But can energy performance certificates (EPCs) actually be relied on?

Calls are growing for a thorough overhaul of the regime amid claims that the information in many may be inaccurate and misleading.

An EPC outlines the energy performance of a property, from A (best) to G (worst), and recommends improvements that could be made.

With many people worried about energy bills and others keen to make their home more energy-efficient for the sake of the planet, they arguably have an important part to play.

But Rocio Concha, director of policy and advocacy at consumer body Which?, told the Observer: “Current EPCs are in desperate need of reform as, too often, the information and advice they contain is inaccurate, difficult to understand or unhelpful.”

Which? says one factor that can contribute to the “lack of accuracy” is that they are valid for 10 years, “regardless of any changes that have been made to the property”. It says this should be cut to five years.

The Observer looked at certificates for homes now on the market, or recently sold, and found some of the EPCs were nine years old. Some appeared to give outdated or incorrect information about the cost of improvements that could be made.

Leading property trade body Propertymark told us the system “probably does need some sort of revamp. If work is done, for example, it needs to be updated as you go.”

The basics

Virtually all homes sold, rented or built since 2008 have to have an EPC. They are designed to show prospective buyers or tenants the energy efficiency of a property.

An assessor will take measurements and look at the construction and insulation, the heating system and lighting. This is all fed into software that generates a rating for the cost of heating, carbon emissions and so on. Suggestions for improvements can range from small, relatively inexpensive changes, such as fitting low-energy lighting and draught-proofing, to major projects such as installing solar panels or a wind turbine.

Property website Rightmove says that in its 2023 home-mover survey, 14.5% of respondents said the EPC would be a major factor determining their choice of property when looking for their next home, with a further 64.9% saying it would be important but not the top priority.

The government reckons about 60% of homes in England, and 55% in Wales, have an EPC. The most common reason for a property not having one is because it has not changed hands since the rules came in more than 16 years ago.

The criticisms

A recent Which? report stated: “Unfortunately there is substantial evidence that the metrics and information in many EPCs may be misleading, and homeowners, tenants, landlords and policymakers could be making decisions based on inaccurate information.”

It went on to say that “a growing number of studies suggest a significant number of EPCs are inaccurate”.

Which? also highlighted other issues, such as quirks in the system that mean, for example, a property owner who replaces a gas boiler with a heat pump can sometimes see their EPC rating fall as a result.

And it flagged concern about how some EPCs “are sold at very low cost and delivered very quickly”.

A Google search last week pulled up companies offering them for as little as £34, which casts doubt on how thorough that cheap a certification is going to be.

Timothy Douglas, head of policy and campaigns at Propertymark, says: “We know agents have concerns about consistency – five different assessors would probably come up with five different EPCs.”

And, he adds, with some properties, “they are recommending some extensive measures which aren’t always practical”.

For example, we found an EPC for a period cottage in a Norfolk village conservation area that suggested forking out a five-figure sum on installing a wind turbine in the small-ish garden.

While many sellers commission a new EPC when they put their home on the market, others who already have a certificate that is within its 10-year validity period will simply use that, perhaps to save money or because they are confident their home will be snapped up more quickly. That means potential buyers could be looking at very out-of-date information.

Or it may be that improvements carried out since the EPC was done mean the property’s efficiency rating should be higher. “It could be a false economy to use an old EPC,” says James Mason, founder of Hawksman Real Estate, based in Surrey.

On the other hand, if the property has been neglected for years, the rating should now be lower.

Rightmove’s property expert Tim Bannister says that updating EPCs more regularly could be helpful to give people more timely property-specific information, “but it needs to be done in a way that’s affordable and practical”.

What we found

We looked at publicly available certificates for homes in Birmingham, Cambridge and King’s Lynn currently on the market, or that have just sold. While in many cases the assessments were carried out fairly recently, we found several where the “current” EPC was between five and nine years old.

For example, one for a four-bed detached home for sale in Birmingham gives figures for how much a buyer might need to spend on energy, and how much they could potentially save, but then says: “This is based on average costs in 2015 when this EPC was created.”

Meanwhile, some figures for the cost of recommended improvements appear to be inaccurate or out of date.

For the Birmingham four-bedder, and for a two-bed semi in Cambridge, also inspected in 2015, both give a typical installation cost for suspended floor insulation of £800-£1,200. However, the Energy Saving Trust website puts the typical cost at about £4,700.

These two EPCs also suggest replacing the boiler with a new condensing model, putting the cost at £2,200-£3,000. The Energy Saving Trust gives a figure of about £3,700 (for a gas boiler).

Several of the EPCs we looked at suggested “internal or external wall insulation”, and put the cost at £4,000-£14,000, though these are two very different things, and that is a wide cost spread. The Energy Saving Trust estimates the typical cost of external wall insulation at about £12,000, and internal at about £7,500, based on a typical three-bed semi.

Meanwhile, an EPC dating from 2019 for a cottage near King’s Lynn that has just sold says that installing a wind turbine could help lift its energy rating to an “A”. It gives a typical installation cost of £15,000-£25,000. However, the Energy Saving Trust says a 6kW pole-mounted turbine costs about £35,000, though it adds that building-mounted ones cost less to install but tend to be smaller and less efficient.

Last summer, the Department for Energy Security and Net Zero said the UK “has made good progress in improving the energy performance of homes,” but that “the government recognises there is more it can do to help consumers use EPCs to make informed decisions”.

It added that an independent review of net zero had recognised “challenges” with EPCs and recommended the government “reforms the metrics to better reflect current relative costs of heat pumps, and account for wider benefits from low-carbon heating systems. The review also recommended that EPCs provide more detailed information to consumers and ensure that EPCs are updated on a regular basis”.

How to get a new EPC

If your home does not have an (EPC), or it has expired, you
will need to get hold of a new one before you prepare to sell or rent out. You will need to find an accredited EPC provider and book an assessment. Your estate agent may be able to help, or a friend, neighbour, family member or local residents’ group may be able to recommend a firm.

Incidentally, there is an easy way for anyone looking to rent or buy – or who is simply a nosy neighbour – to check the EPC of a property in England, Wales or Northern Ireland. Go to epcregister.com and type in the postcode, or the street name and town/city, select the property from the list. You can then view its EPC. If the property hasn’t been sold or rented out for years, it may not be on the system or its EPC may have expired.

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