Changes to the EPC system took effect on 15th June 2025. This sees the introduction of RdSAP 10 and an update to the software used to assess the energy performance of existing residential buildings. The aim being to improve the overall accuracy of EPCs. We look at what the changes entail, including how they might affect landlords, agents, tenants and those selling their home.

Better accuracy is needed with the EPC system

The shortcomings with the current EPC system have been long recognised in the industry. And that’s a real shame as EPCs were initially designed as a simple means for renters and homebuyers to compare the energy efficiency of homes. Too often, EPCs have been inaccurate or unreliable within the current system framework. Take a scenario where an EPC might recommend you do costly building work. And then you find out the EPC was inaccurate and the work you have done turns out to be completely unnecessary. With such expensive ramifications, it’s no wonder we welcome the changes to the EPC system.

Why is an EPC important?

It was back in 2007 when EPCs first came on the scene. They formed part of the home seller’s Home Information Pack (HIP). And they were designed to help prospective buyers compare the energy use and environmental factors of different properties. The HIPS didn’t last more than 3 years, but a valid EPC continued to be required for anyone selling or letting a home, as they still are today.

An EPC rates a home from A (very efficient) to G (very inefficient). In the case of low ratings, cost-effective suggestions or recommendations are given to improve the property’s energy efficiency. When reliable, accurate information is given with an EPC, it becomes a helpful tool for homeowners and landlords. A good EPC rating can help sellers demand higher asking prices on properties, for example. Likewise, landlords can charge higher rents on rental properties. You can find out more about this in our article ‘Boost your EPC rating and add value’.

So, what are the changes to the EPC system?

With the new version of the energy assessments coming by way of the RdSAP 10, there are several changes. These include the data collected on properties and revising the previous default assumptions.

Here are just some of the key changes:

–           Collecting more data on properties. Energy assessors will go into more detail, collecting and recording more specific information about properties. This could include the type of glazing and its condition. Then there will be evidence-based data collection for heating system efficiency, looking at model numbers, manufacturer data, even smart heating controls. In the case of home improvements where homeowners have had insulation installed or new glazing fitted, evidence by means of documentation will be required.

–           Better measurement of heat retention and energy use. This will be done by refining the measurements of a property’s floor area and insulation levels. So, if you have invested in property insulation, you should see the benefits in your EPC rating.

–           Differentiating property types. Rather than relying on default assumptions, the changes to the EPC system will adjust how heat loss is calculated for flats and terraced homes. This is great news for these property types, as they could see improved EPC ratings.

The impact of the changes to the EPC system on landlords, tenants and agents

The biggest and most important step we advise landlords (and homeowners looking to sell), is to start gathering as much documentation and information together as possible. Energy assessors will be working from the data collected on the property, so it’s crucial you can provide evidence for improvements like insulation, heating or boiler upgrades, double glazing, solar panels, etc. Without the evidence, EPC ratings may be reduced, despite the fact the work has been done. So, collecting and keeping the paper trail for such work is imperative!

With the assessment being more comprehensive, you should expect to pay more for an EPC certificate. We’re already seeing price increases from our side as letting agents. Bear in mind the energy assessors will need to spend more time at a property, collecting the necessary data.

All round, the changes to the EPC system ought to bring more confidence in how accurate they are. Tenants will be able to easily identify which properties are the most energy efficient. Homeowners too can make clear the energy-efficient measures they have taken.

And homes with an excellent energy rating can command higher prices: both selling prices and monthly rents. They will certainly attract more buyers and interested tenants, often leading to a quicker sale or take up of a tenancy, after we’ve done the necessary checks for you.

Jameson and Partners is a local Altrincham-based estate agent. Whether you’re a landlord or homeowner, we can highlight the best steps for improving your EPC rating. And once you have an EPC certificate for your property, you can contact us for a FREE valuation for selling or letting your home. Call our professional team on 0161 941 4445.