Refurbishing Your Home? Consider Your EPC Score

By Ian on Tuesday 22nd August 2023

Wind turbine to reduce energy usage

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If you are refurbishing your home, its the perfect time to add some energy saving upgrades, reduce your monthly expenditure and boost your EPC score. Read on for our top tips!

Improving your EPC score is not just about saving money or reducing your carbon footprint. As discussed in a previous article, homes with a better EPC score are worth more money on the housing market!

Check your EPC

But first, take a look at your latest Energy Performance Certificate, if its a few years old, its worth updating your EPC. There are personalised recommendations on each report and that will tell you where you need to concentrate your efforts. And your money! Below we’ll look at the main things that are worth doing when refurbishing your home. It’s important to note here that you need to evidence every upgrade you install. Take photos, keep invoices or get a certificate. Your EPC assessor will need to see evidence in order to input any upgrades on the software.


The three main areas to insulate are your walls, loft and floor.

Wall insulation also has three main types too. Cavity, external and internal insulation. Lets start with cavity. This is usually polystyrene beads injected into the cavity through the external brick. Most modern houses have at least some cavity wall insulation, its not very disruptive and is usually installed within a few hours. External wall insulation is attached to the outside wall of the house then rendered over to hide it. Internal wall insulation is where we can add to the cavity insulation and the perfect time to do this is part of a refurb.

Internal wall insulation is fitted around a timber frame that is constructed on the internal side of your external walls. You’ll lose a bit of floor space but if your knocking the plaster back to brick, we’re probably talking around 20-30mm on each wall. Once the timber frame is constructed, you can fill the gaps between the frame with mineral wool batts or a rigid board insulation like Kingspan. This acts as an additional blanket around your home. If you are doing a rewire, this will make first fix electrics easier as there will be little chasing out to do. An alternative to timber framing, is to dot and dab insulated plasterboards. You sometimes get mould patches on the plasterboard where the dabs are whilst the adhesive dries out.

Everyone knows about loft insulation. I won’t go into too much detail with this. Just ensure that you’ve got at least 270mm and any storage boarding is raised higher that the insulation without compressing it. Joist insulation is better than rafter insulation on the EPC.

With floor insulation you’ve got two alternatives depending on your floor type. With either, you’ll probably consider underfloor heating at the same time.

  • Solid Floor: Usually concrete or asphalt, you’ll need to dig this up, lay some rigid insulation boards, run your underfloor heating pipework and pour your new subfloor. Don’t forget to snap a pic of the insulation before the pour.
  • Suspended Timber: A little easier to do, especially if you have a crawl space with an access hatch. What we would expect to see is timber running across the underside of the joists which is supporting your chosen insulation. On top of this is your underfloor heating pipework and a layer of screed before timber floor boards are (re-)fitted.

Heating Systems

Boiler or heat pump? Most refurbishments should either have a very efficient ErP gas boiler or some form of heat pump. I’m biased and would pick an air source heat pump. Either way, whilst wider works are in progress, now is the perfect time to rip out all the old pipe work and lay new, insulated pipes. Furthermore, if you really want to save every ounce of energy in the building, consider the following.

  • Flue Gas Heat Recovery (FGHR): This will remove the heat from your gas boiler flue and recirculate it back in to your central heating system. Therefore, reducing the workload of your boiler.
  • Waste Water Heat Recovery (WWHR): Similar to FGHR, this clever system removes heat from water travelling down your waste pipes from your bath or shower.

Windows & Doors

Depending on your starting position, these won’t have too great an impact on your EPC score. Let’s take the opportunity to gain all the points we can though, right? If you upgrade your windows and doors, its essential to get the u-value from your supplier. U-values are broad and the EPC uses a generic u-value for all windows and doors installed after 2002. In simple terms, a u-value is the measurement of how well the material acts as an insulator. The lower the u-value, the better it insulates your home. If you’re choosing new doors, choose a composite model over a uPVC alternative.


Photovoltaic (PV) panels are the ideal scenario here. I’ve helped a few customers look at the impact of PV panels on their EPC scores and nothing comes close to the boost they give. They have a significant upfront cost, that is true. However, when you consider the reduction in energy bills (especially with current prices), more often than not, its a no brainer. To sweeten the deal, PV panel owners can take advantage of the Smart Export Guarantee and sell excess energy back to the grid. The considerations that I would advise are

  1. Direction. You need to have a decent amount of south (ish) facing roof space. 20-30m2 is the target.
  2. Overhang. Are there any trees or tall buildings that would block sunlight for any proportion of the day?
  3. Roof Angle: You’re looking for an angle between 30-45 degrees to get maximum output on your panels.
  4. Connection to Meter: Without connecting your panels to your electric meter, you’ll be missing out on the SEG and can’t gain full marks for solar panels on the EPC.

Solar water heating is another renewable to consider. They look similar to solar panels and sit on the roof of a property, but they work like FGHR and WWHR by adding captured heat into the central heating and / or the hot water system.

Wind turbines are the last renewable that the EPC software can handle and it loves to recommend them in rural areas. To input these, we’ll need to know the rotor diameter and the height above the ridge. It’s worth getting an expert involved to determine if these would be worth the investment.


When you’re diving into a home refurbishment, it’s easy to get caught up in aesthetics and design. But as we’ve explored, there’s a golden opportunity here to weave in energy efficiency and boost that EPC score. It’s not just about ticking boxes or meeting standards, it’s about creating a home that’s future proofed, cost effective, and environmentally conscious. By integrating these energy saving measures, you’re not only enhancing your home’s market appeal but also ensuring it’s a space that’s warm, efficient, and sustainable. So, as you roll up your sleeves for the next home project, remember the value of a great EPC score.

If you’d like some personalised advice or want to book an EPC get in touch.

About the Author

About Ian Kay

Ian is a seasoned energy assessor helping his customers, reduce energy usage and save money on their bills. He holds qualifications from both City & Guilds and ABBE for Domestic EPCs and Commercial EPCs (Level 3 NDEA and Level 4 NDEA). With a background in the building trade he can provide his customers with a unique perspective and advice. Ian combines his deep industry knowledge with practical advice to create blog posts that help visitors understand the complexities of energy performance certificates and reducing operating costs. When not immersed in the world of energy assessments, Ian enjoys exploring the great outdoors and spending quality time with his family.

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