New Changes to the EPC in 2024: What this will mean for Coventry residents
Residents in Coventry will be seeing a major change to the EPC from mid-2024.
This will help to create more accurate ratings on the energy performance certificate and in some cases produce a higher rating.
EPCs uses a methodology called Reduced Standard Assessment Procedure or RDSAP for short. The new methodology is known as RDSAP 10.
The major changes that are coming in means additional information will be gathered by the Assessor. Here is a summary of the main changes.
1. Assumption of 100mm of loft insulation when thickness of insulation can’t be determined.
2. Assessor will be required to measure all windows and their orientation.
3. Additional options for measuring roof rooms.
4. New age band for properties built after 2023.
5. PV diverters and battery storage can be accounted for by the Assessor.
6. Heat Pumps to be recommended more.
7. Air tightness test values will be able to be entered into the software.
We’ll look at each of these in more detail.
1. Assumption of 100mm of loft insulation when thickness of insulation can’t be determined.
Any property where the loft insulation can’t be determined, will now have an assumption made of 100mm being present. Previously an assumption of “no insulation assumed” would have used resulting in a lower rated EPC.
This simple but very important change will have a big impact on many EPCs.
Under the previous EPC conventions, if the Assessor couldn’t measure the thickness of the insulation, either because the loft was boarded or full of customer items, the software would make an assumption of the loft insulation based on the age of the property and the building regulations for that age, as shown in the table below:
This meant that if your property was built before 1967, where the loft insulation couldn’t be determined, then it would say on the EPC “no insulation assumed” and rate the EPC based on that assumption, when in reality there may have been insulation present.
The old EPC convention would always show the worst-case scenario where there is no evidence.
With loft insulation being one of the main rating factors, the new change to making an assumption of 100mm being present, will mean that many properties will have a better rating if they simply got their property reassessed under the new RDSAP10 methodology.
This may help many Coventry landlords get to the minimum EPC rating of an E if it was previously an F rating and the existing EPC says “no insulation assumed”.
We can help if you wish to arrange a new EPC.
2. EPC will now measure windows and orientation: what this means.
Under the new RDSAP10, windows and their orientation will be accounted for in the software.
This means that solar gain will now be reflected in the software.
We all know the feeling of the heat generated by the sun through glass.
This means that certain properties with a higher percentage of glazing between the west and east orientation will benefit from solar gain thereby requiring less energy to heat the home, thereby given a better rating on the EPC.
3. Additional options for measuring roof rooms
Roof rooms also known as loft conversions will now require assessors to take additional measurements of the different construction make up.
This will result in a more accurate representation of the thermal performance of that part of the property if the information can be obtained.
These are the areas of a loft conversion that can now be accounted for individually in an EPC.
- Top horizontal loft
- Sloping ceiling
- Vertical studs
- Residual loft space
- End gable walls
4. New age band for properties built after 2023 added
Properties built after 2023 are built with better thermal values than the previous building regulations of 2012.
Technically speaking, properties built after 2023 should already have an EPC done from the building plans called a SAP EPC.
This is because every single element of the building construction would be known and no assumptions are necessary.
This is compared to existing buildings using the RDSAP methodology which stands for Reduced Standard Assessment Procedure, where certain thermal elements of the property won’t be known, therefore assumptions would have to be made based on the age of the property.
Where this new age band will be used is for newly built extensions that have been added to the existing property.
This will accurately reflect the improved thermal values for that section of the property, which will result in a better rating.
5. PV diverters and battery storage can be accounted for by the Assessor
A PV diverter is a device that redirects surplus electricity generated by solar panels to power household appliances or heat water, maximising the use of solar energy and reducing wastage.
Battery storage for solar panels allows excess energy to be stored for later use, increasing energy independence, reducing electricity bills, and providing backup power during outages.
Both these technologies will be able to be entered into the new epc software.
Once the software is released, we will be able to tell the impact of these technologies on the epc ratings.
6. Heat Pumps to be recommended more
In the previous version of the EPC, heat pumps were never recommended as an improvement.
In the newer RDSAP 10 version, a heat pump may be recommended as an alternative heat source if both of the following apply:
• There are no recommendations on the EPC for any insulation improvements and
• It produces an energy saving of at least £10 on the current heating system.
7. Air tightness test values will be able to be entered into the software
Being able to enter an air tightness test value into the EPC software is a totally new data input point that may help to improve the EPC rating.
An air tightness test measures the extent to which air can leak into or out of a building, using a fan to pressurise or depressurise the structure and detecting leaks.
This test helps improve energy efficiency and indoor air quality by identifying areas that need sealing.
A good air tightness test result of 6 m³/(h·m²) at 50 Pa, or lower, can improve the EPC rating by up to 3 sap points.
Limitations to the EPC
Even with the new changes, the current Energy Performance Certificate (EPC) system has limitations and criticisms, including its reliance on standardised assumptions that may not reflect actual energy use, leading to potentially inaccurate ratings.
It often fails to account for modern energy-saving technologies and user behaviour, and the assessment process can be inconsistent due to variations in assessor expertise.
Critics also argue that EPCs do not adequately incentivise energy-efficient improvements or provide enough actionable information for property owners.
The government is already in the process of building a new energy rating system called the Home Energy Model.
This model will be used as an energy efficiency compliance tool for all new buildings from 2025 as part of the Future Building Standards.
The government propose that the Home Energy Model will also become the main methodology for producing EPCs in the future.
Home Energy Model
There are future talks about replacing the EPC with a totally different system called Home Energy Modelling.
This is still at the early stages, but there are talks about there being a central calculator on a government website where the energy assessment of the property can be input by registered assessors.
From this calculator, Coventry homeowners can access their property data and recalculate the results based on improvements they may want to explore.
There are also talks that it will use more accurate weather data, so for example a property in Coventry may perform differently to a property in Plymouth due to its location, where the current EPC does not take that into account.
There is soon to be a consultation paper and we will provide more detail when it is available.
Summary
The forthcoming changes to the EPC in mid-2024 will bring more accurate energy performance ratings for Coventry residents by updating the assessment methodology to RDSAP 10.
Key changes include assumptions of 100mm loft insulation when undetermined, measuring windows and their orientation, additional options for roof room measurements, a new age band for properties built after 2023, and accounting for PV diverters, battery storage, and heat pumps.
Despite these updates, the EPC system still faces criticisms for relying on standardised assumptions that may not reflect actual energy use and for not adequately incentivizing energy-efficient improvements.
The government plans to introduce the Home Energy Model as a future replacement, aiming for more accurate assessments and better user engagement.
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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.
Rickie – when will the EPC system be recalibrated to give points to ASHPs over gas boilers? I am a landlord wanting to do the right thing and go green but my EPC wouid go down from a C to a D with an ASHP andmy property woukd no longer qualify for letting from 2028.
Any suggestions? Responsible landlords are desperate to have their green investments recognised by the EPC system.
Hi Astrid
The EPC is due for a big change in the spring of 2025. However, it’s still unlikely to address the issue with ASHPs rating lower than gas boilers.
The EPC rating is based on the running costs it takes to provide heating and hot water to the home. Gas is still significantly cheaper that electicity (with gas costing around 6 pence per kwh compared to electricity costing around 4 times as much at 25 pence per kwh). So even the typical heat pump with an efficiency of 350% won’t be as cheap as a gas boiler with a typical efficiency of 90%.
An air source heat pump will have significantly lower carbon emmisions that a gas boiler. The EPC does show this, but only in small print lower down on the EPC. The example below shows this where the EPC rating is a D, but the Carbon Emmision rating is a C.
EXAMPLE OF THE RATING OF A PROPERTY WITH AN ASHP
EXAMPLE OF SAME PROPERTY SHOWING CARBON EMISSION RATING
There is a plan to replace the EPC model in buildings called the Home Energy Model, this may address some of the issues of how properties are rated. This is still at an early stage but we will have to wait and see when and if it comes into fruition