All About Your EPC Rating – Part 2

All About Your EPC Rating – Part 2

To understand how far infrared heating can give you a better EPC rating, you first need to understand what SAP and RdSAP means.

What is SAP and RdSAP?

SAP stands for ‘Standard Assessment Procedure’ and is a formula that is used to calculate your EPC rating. The SAP is essentially a very thorough list of calculations to judge the overall performance of your building. In turn, this is what produces the final EPC certification as part of the Building Regulations compliance. The Standard Assessment Procedure is used to produce the EPC certificates for new build properties. The RdSAP (Reduced Data Standard Assessment Procedure) however is used to produce the certificates for already existing homes.

The SAP documentation and guidelines as to how the assessment take place are usually updated every 4 years, the most recent update being on 24th July 2018. On this date the Department for Business Energy & Industrial Strategy (BEIS) and the technical authors of the Building Research Establishment (BRE) published the next version of SAP. This is now known as SAP 10.

While the RdSAP has its benefits, there is one major flaw in this assessment. It is a ‘’Reduced Data’’ assessment. If you are doing a retro fit or renovation of your property and you’re getting the certification sorted out… I would think again about the RdSAP route. This type of assessment has a lot of assumptions because they assume that a lot of the newer works such as insulation, windows etc is the same as the original EPC certificate. So rather than doing a whole new assessment of the property using the usual SAP formula – they try and carry over as much as possible.

While the general SAP formula is very difficult to find, we do know that it has a lot more flexibility and data to choose from. Especially in terms of heating when it comes to calculating your EPC rating. For example, with the RdSAP formula the infrared heating will fall under ‘’Electric Panel Heating’’ which is considered very inefficient. With the SAP formula that is used for new builds, you can disclose exactly how much power you are drawing using your electric heating.

How can I get a better EPC with FIR?

You may now be thinking ‘’well I’ve renovated my property, but I’m stuck with a super low EPC that I can’t change because it isn’t a new build.’’

Well fear not! If you’ve changed your primary heating source and have access to full architect’s drawings, floor plans, elevations, and cross sections then you’re in luck. Thanks to Mark Hunt at MH Energy Consultants, you can now get a full SAP on your newly renovated property. Thus, giving you a far more accurate EPC score!

An example which we found online, after an RdSAP assessment on a newly renovated property, with IR heating, they were left with an E rating. This is close to being the worst possible rating. With a full SAP report, the house was then changed up to a C as they were then able to record the power rating of the heaters. After the C was approved, it flagged up as it was rated two whole grades above the original. After a full audit, they came back with 100% accuracy and secured the C rating.

It is worth mentioning that a full architects’ drawings and floor plans do come at a cost, and this is discretionary to the company that you use. However, we fully believe that if you are trying to rent out your property, it will be worth every penny. Without this SAP report, it may not even be possible to rent your property out in the first place.

What else can I do to help my EPC rating?

While heating is one big thing that contributes to your EPC, there are a lot of other factors to consider. It can be easy to install a new FIR heating system and instantly think that your EPC is going to be changed to an A. But to have the best chance of getting a better score, you need to look at other aspects as well.

  • Double Glazing – Upgrading your window and door quality will help with your EPC rating as it is designed to retain heat as well as keep noise levels lower.
  • Loft insulation – Loft insulation is easy to install and cheaper than you’d think. It can also make a huge difference to your bills. We recommend ensuring it’s at least 270mm in thickness
  • Lighting – You can replace existing low energy lighting with LED lighting instead.
  • Cavity insulation – if your property has a cavity wall, ensure that it is insulated – this can make a huge difference.


What did you make of this article? Do you have any further questions? Get in touch on 01205 821 796 or