Making sense of your Energy Performance Certificate

Most homeowners know they need an Energy Performance Certificate when selling a property.

Far fewer know what it actually means.

You open the certificate, see a coloured chart, a letter somewhere between A and G, a list of possible improvements and a collection of estimated figures. But what should you actually pay attention to?

And, more importantly, what might a buyer notice?

Here's how to make sense of your EPC before putting your home on the market.

What is an Energy Performance Certificate?

An Energy Performance Certificate, usually shortened to EPC, is a standardised assessment of the energy efficiency of a property.

It gives the property an energy efficiency score and places it into one of seven bands:

• A: 92 to 100+
• B: 81 to 91
• C: 69 to 80
• D: 55 to 68
• E: 39 to 54
• F: 21 to 38
• G: 1 to 20

A is the most energy efficient.

G is the least.

The certificate also provides information about where the property is likely to lose energy and suggests improvements that could increase its rating.

Where do I find my EPC?

EPCs for properties in England, Wales and Northern Ireland are normally held on the government's public EPC register.

If your property already has a valid certificate, you may not need to arrange another one.

An EPC is generally valid for 10 years, although there may be reasons to obtain a newer assessment if substantial improvements have been made to the property.

For example, you may have:

• replaced an old heating system
• added insulation
• installed solar panels
• replaced windows
• extended the property
• carried out a major renovation

If those changes could significantly improve the property's rating, an updated EPC may present the home more accurately to buyers.

The first number to look at: your current score

The most prominent part of your EPC is your current energy efficiency rating.

For example:

Current rating: D 64

The letter is useful, but the number tells you more.

A property scoring 64 is comfortably within band D.

A property scoring 68 is also a D, but it is only one point away from reaching a C.

That distinction can matter if you are considering improvements.

Instead of asking:

“How do I improve my EPC?”

a more useful question might be:

“What would it take to move from 68 to 69?”

Sometimes the difference between EPC bands is much smaller than the coloured chart makes it appear.

Then look at the potential rating

Your EPC normally shows both a current rating and a potential rating.

For example:

Current: D 61
Potential: B 83

That does not mean the property will automatically become a B.

It means the assessment has identified improvements which, according to the methodology used, could potentially increase the property's score.

The gap between the two figures can be useful.

A property already rated B with a potential B has relatively limited room for improvement.

A property rated E with a potential B may have several significant opportunities to improve its energy performance.

What does the EPC actually assess?

An EPC isn't simply based on your energy bills.

Instead, it looks at characteristics of the building.

These can include:

• walls and wall insulation
• roof and loft insulation
• floor construction
• windows
• heating systems
• heating controls
• hot water
• lighting
• renewable energy
• the size and shape of the property
• the age and construction of different parts of the building

This is why two households with identical energy bills can have very different EPC ratings.

The certificate is assessing the property rather than the behaviour of the people living there.

What does “energy efficiency” mean on the certificate?

Your EPC may give individual elements of the property descriptive ratings.

For example, you might see something like:

Walls: Poor
Roof: Good
Windows: Average
Main heating: Good
Heating controls: Average
Hot water: Good

These are useful because they help explain why your overall rating is what it is.

If most of the property performs reasonably well but the walls are rated very poorly, that may be one of the main factors limiting the overall EPC score.

Likewise, an efficient new boiler cannot completely compensate for a poorly insulated building.

Why does the EPC sometimes seem wrong?

This is a common concern.

An EPC assessor cannot dismantle your home to establish exactly how it was constructed.

They cannot normally drill into a wall to see how much insulation is present or lift your floors to inspect underneath them.

For existing homes, the assessment therefore combines what the assessor can observe with information about the age and construction of the property.

Where something cannot be verified, assumptions may sometimes be used.

This makes evidence particularly important.

If you know your home has had significant energy improvements, try to find paperwork relating to them before the assessment.

What paperwork should I keep for an EPC?

Useful evidence can include:

• building regulation certificates
• planning documents
• extension paperwork
• insulation guarantees
• invoices for insulation work
• window installation certificates
• boiler documentation
• heat pump installation records
• solar panel documentation
• completion certificates
• specifications from major renovation work

For example, insulation inside a converted loft may be completely hidden once the work is finished.

Documentation showing what was installed can therefore be much more useful than simply telling the assessor that insulation is there.

What do the recommended improvements mean?

Your EPC may include a list of measures that could potentially improve the property's energy performance.

These might include:

• increasing loft insulation
• adding wall insulation
• improving heating controls
• upgrading the boiler
• installing double glazing
• insulating the floor
• installing solar panels
• fitting a heat pump

The recommendations can also include estimated costs and the potential improvement in the property's rating.

These should be treated as guidance rather than a renovation shopping list.

You do not necessarily need to carry out every recommendation.

Do EPC improvement costs mean that's what I will actually pay?

No.

Any costs shown on the EPC are estimates.

The real cost could vary substantially depending on:

• where you live
• the size of the property
• accessibility
• the specification you choose
• labour costs
• the existing construction
• additional work required

If you are considering an improvement, obtain current quotes rather than relying solely on the figure shown on an older EPC.

What is the environmental impact rating?

Depending on the certificate format, you may also see information relating to carbon emissions or the environmental impact of the property.

This is related to energy performance, but it isn't necessarily identical to the headline energy efficiency score.

Different heating fuels and technologies can have different carbon impacts.

For most sellers, however, the main EPC letter and numerical score are likely to be the figures buyers recognise first.

What do the estimated energy costs mean?

Your EPC may show estimated costs for heating, hot water and lighting.

These figures can be useful for comparing properties, but they should not be confused with a prediction of your actual energy bill.

Your real costs depend on factors such as:

• how many people live in the house
• how warm you keep it
• how often you are at home
• your energy tariff
• how much hot water you use
• your appliances
• changes in energy prices

Someone who keeps their home at 17°C will use a very different amount of energy from someone who keeps the same property at 23°C.

The EPC provides a standardised comparison rather than a personalised bill forecast.

Why might my new EPC be different from my old one?

You may have an old EPC showing one rating and receive a different score when the property is reassessed.

That does not necessarily mean the house has suddenly become more or less efficient.

Possible reasons include:

• different information being available
• improvements made since the previous assessment
• an assessor recording the construction differently
• changes to the EPC methodology
• previously hidden information being evidenced
• extensions or alterations being assessed differently

This is why an EPC from several years ago should not always be treated as a guaranteed prediction of your next result.

Is a D rating bad?

Not necessarily.

A large proportion of Britain's existing housing stock was built long before modern energy standards.

Older properties can therefore have lower EPC ratings than newly constructed homes.

A D-rated Victorian terrace, for example, needs to be considered in the context of similar homes rather than compared only with a newly built property.

That said, buyers are becoming increasingly aware of energy efficiency and running costs.

A property's EPC may therefore form part of the comparison when someone is choosing between otherwise similar homes.

Is a C EPC good?

For many existing homes, a C can be a strong result.

The significance depends on the property type, age and local market.

A modern flat with a C may not be particularly unusual.

A substantially upgraded period property reaching a C could represent significant improvement over its original construction.

The number within the band is again useful.

A C69 and a C80 both appear as C-rated properties, but there is a considerable difference between their underlying scores.

Should I improve my EPC before selling?

Sometimes.

But don't assume that spending the most money will produce the best return.

Start by looking at three things:

Your current score

How far are you from the next EPC band?

Your recommended improvements

Which measures are expected to make the largest difference?

The likely cost

Could a relatively inexpensive improvement materially improve the rating?

If your property is sitting at D68, a modest improvement that takes it to C69 may be worth investigating.

If it is sitting at D55 and reaching a C would require major structural work, the calculation is very different.

What will buyers care about?

Most buyers aren't going to analyse every line of your EPC.

They are more likely to notice:

• the headline EPC rating
• whether the home appears expensive to heat
• the type of heating system
• insulation
• double glazing
• solar panels or renewable energy
• obvious recommended improvements

A poor EPC does not automatically prevent a home from selling.

But unexplained issues can give buyers something else to worry about.

Knowing what your certificate says before the property goes on the market means you can decide whether to address anything rather than discovering it after a buyer has.

EPC terms explained

Here are some of the common phrases you may encounter.

Current energy rating

The property's calculated energy efficiency at the time of assessment.

Potential energy rating

The estimated rating that could be reached if recommended improvements were made.

RdSAP

Reduced Data Standard Assessment Procedure. It is the methodology generally used to assess the energy performance of existing homes.

Main heating

The principal system used to heat the property.

Secondary heating

Any additional heating source, such as a fireplace or room heater.

U-value

A measure of how easily heat passes through part of a building, such as a wall or window. Lower U-values generally indicate better insulation.

Low-energy lighting

Energy-efficient fixed lighting included within the assessment.

Primary energy use

A measure relating to the energy required to provide services such as heating and hot water, including energy used before it reaches your home.

Your EPC is more useful than just a letter

It is easy to treat an EPC as another certificate you need before selling.

But read properly, it can tell you quite a lot about your property.

It can highlight:

• where the home is losing energy
• what has the biggest effect on its rating
• whether relatively simple improvements are available
• how close you are to the next EPC band
• what potential buyers are going to see

And like many parts of selling a home, it is much better to understand this information before you need it urgently.

Find out what buyers will see before your home goes on the market

Tepilo helps you bring together important information about your property before you sell, including the information buyers, estate agents and conveyancers may eventually rely on.

Check your EPC early, understand what it says and identify anything you may want to deal with before your property reaches the market.

Start preparing your home for sale with Tepilo.