On June 15th, 2025, a new calculation engine called RdSAP 10 was introduced for domestic Energy Performance Certificates (EPCs). As a result, there are significant changes to how Domestic Energy Assessors (DEAs) are required to collect and enter information for EPCs.

Why has RdSAP 10 been introduced?

The new RdSAP10 methodology will enable more accurate EPCs to be created which better reflect the energy performance of individual buildings. In the last decade there have been significant technological improvements which can now be taken account of within the EPC. RdSAP 10 will also make many fewer assumptions about aspects such as glazing, lighting and ventilation which will improve the accuracy of the report.

What extra information do assessors need to collect?

There is a total of 32 changes to the EPC system! Assessors will need to collect additional information on aspects such as roof rooms, ventilation, lighting and insulation types and thicknesses. However, by far the biggest change going forward is that assessors will need to take individual measures for all windows present within the property. For larger properties which have a lot of glazing presents this will add a significant amount of time to how long an assessor will need to spend both on the property as well as creating the EPC.

What does this mean for my EPC?

Your EPC will have less assumptions, it will be a more accurate representation of the property and provide you with more information and data about how your property is performing. To account for the additional time required to collect and enter all the extra data, Assessors will need to account for the extra work and time involved with each report and a price increase should be expected for obtaining an EPC.

What happens next?

Well from 15th June only RdSAP10 will be able to be used to produce EPCs for existing buildings. However, there are likely to be further changes to the EPC in the next 2 years.

The Government have recently consulted on EPC reform where they are proposing wholescale changes so that the EPC can be more useful document and accurate to the Government’s environmental policy aims. They are also consulting on the minimum energy efficiency standards for private rented properties.

More information on these consultations can be found:

• EPC Reform Consultation
• MEES Consultation

Recent Commercial EPC for this bold building, on the Whitehaven dock.

We provided commercial EPC & re-visit after improvements to achieve A rating.

Redevelopment of two blocks of flats on Churchill Place & Wallace Lane Maryport, we carried out pre-assessments of the flats, then consulted with Thomas Armstrong’s on the Project, to achieve C & above ratings on all of the flats.

Senhouse Street, Maryport – EPC’s carried out on newly renovated flats on Senhouse Street Maryport, for local business owner & Landlord John George.

“We were delighted with local company that we could trust to take the hassle of ensuring we were compliant with MEES regulations” John George

It’s not just property sellers who need an Energy Performance Certificate (EPC). Anyone planning to rent out properties will also need one, whether for a conversion or an existing rental property. We’ve worked with developers on some stunning properties in the Lake Distract and elsewhere in Cumbria. Lipwood House was a particularly impressive project in a gorgeous location.

Located in Windermere, down a private road, Lipwood House was originally a Victorian gentleman’s residence. The building had been adapted into apartments in the past but these no longer met standards of fire safety and there were things like the window frames and roof that needed repairs too.

West Cumbria EPC did all the EPC assessments and Certificates once the apartments were completed, working for Lind Studio, the architects.

“We were able to assess the apartments upon completion and provide an EPC for each one,” says Jacqueline Gartland of West Cumbria EPC, “and they were beautiful. But it was a shame that we were only brought in at the final stages. If we can get involved from the beginning of a conversion or renovation project, our assessment is much more straightforward as we can gather all the evidence as the work proceeds so that each EPC gives the property its best energy rating for rental.”

If you’re a developer or a landlord and you’d like to find out more about working with us, please get in touch.

It’s free to have a chat and discuss your plans and bringing us in early could make all the difference.

Our assessors are highly trained and fully qualified. We also ensure that our expertise is regularly checked, certified, and updated. The company that we use for that is STROMA, one of the biggest EPC accreditation bodies in the UK. But does that make any difference for you? We think it makes a BIG difference!

For a start, we’re all about EPCs (Energy Performance Certificates) and other aspects of property and energy assessment. That’s our focus, that’s our speciality and we invest time (and money too) to make sure that we’re up to date and giving the best value-for-money advice on energy efficiency to our clients.

STROMA has several divisions to its business and the common thread is all about safety, sustainability, and regulatory compliance in the construction sector. Consultants from STROMA work alongside construction project teams across the UK to build smarter and more efficient buildings.

STROMA Certification is the division that we’ve worked with at West Cumbria EPC. Its team provides training courses for energy assessors and then certification schemes to reinforce their expertise. There are different courses and certifications for all sorts of buildings – domestic, commercial, new build domestic, public buildings and retrofitted properties.

The assessors at West Cumbria EPC are qualified for domestic properties. That means that we can assess and provide the essential EPC documentation for all sorts of residential housing, for private landlords, for private home sellers, for housing associations – you name it – and for estate agencies and rental companies too.

To keep our certification, we’re always learning, and we currently have assessors working towards qualifications in the commercial sector too. We hope to offer EPC’s for commercial property owners, sellers and renters in future, so watch this space for news.

If you’d like to find out more about what’s involved in an EPC and our STROMA certification or, of course, if you need to book an EPC assessment, please don’t hesitate to get in touch.

You can find out more about STROMA Certification at https://www.stroma.com/certification.

Many of our referrals come via estate agents and letting agents. That’s our bread-and-butter work and we really appreciate their commitment to us as a local small business. If you’ve found us independently and wonder if you could book an assessment with us direct, that’s a Yes and we’d like to explain why that could work well for you.

For a start, we’re all about EPCs or Energy Performance Certificates and other aspects of property and energy assessment.

An EPC isn’t actually a certificate at all. What you get is a four-page document that sets out the energy efficiency of your property on a traffic light system of A to G. You’ll have seen this same approach on kitchen appliances and a grade A is the most energy efficient.

As well as your current rating, an indication of how much it will cost to heat and power the property, an EPC also includes recommendations of energy-efficient improvements, the cost of carrying them out, and the potential savings in £££s that each one could generate. And it will show you the rating that your property could achieve with those measures in place.

Many people selling a property or renting one out will go with the DEA (Domestic Energy Assessor) that their agent recommends but we like to think that coming direct to us gives you a few added benefits. The main thing is that we’re more flexible than most on the timing of your assessment visit – we work on Wednesday evenings so that you don’t have to have time off work to be there to meet us. And the other additional benefit is that we know our advice on those extra measures could be really useful to you now and to your buyer or tenant in future so we make it a priority to spell out the possibilities and benefits too.

If you’d like to find out more about what’s involved in an EPC and how to make sense of the report, please don’t hesitate to get in touch.