If you’re a homeowner in the UK, you’ve likely heard of an EPC, or Energy Performance Certificate. It’s a document that rates your home’s energy efficiency, scoring it from A (super efficient) to G (about as efficient as leaving your windows open in January).
With energy bills soaring and the government pushing for greener homes, improving your EPC rating can save you money, make your home more comfortable, and boost its value. For landlords, a minimum E rating is a legal requirement for rental properties, with plans to raise this to C by 2030.
So, how do you improve your EPC rating? You don’t need to be a DIY expert or have deep pockets. This guide covers practical, cost effective steps, plus some bigger investments for those ready to commit.
What Is an EPC, and Why Does It Matter?
An Energy Performance Certificate is like a report card for your home’s energy efficiency. It assesses factors like insulation, heating systems, windows, and energy usage (or waste). A higher rating means lower energy bills and a smaller carbon footprint. For homeowners, a better EPC rating makes your property more attractive to buyers, who doesn’t love a home that’s cheaper to run? For landlords, it’s non negotiable: since 2020, rental properties in England and Wales need at least an E rating.
Improving your EPC rating isn’t just about compliance. It’s about keeping your home warmer, cutting costs, and helping the environment. With energy prices in 2025 still high, every improvement counts.
Step 1: Get Your EPC and Understand It
First, know your starting point. If your home doesn’t have a recent EPC (they’re valid for 10 years), book an assessment with an accredited domestic energy assessor. It typically costs £60 to £120, depending on your location and property size. The assessor will visit, inspect, and provide a report with your current rating and tailored recommendations.
Your EPC report is more than just a letter grade, it’s packed with advice. It highlights where your home loses energy (often the loft or walls) and suggests fixes, from quick wins to larger projects. Check the “potential rating” to see what you could achieve with the recommended upgrades.
Step 2: Insulate, Insulate, Insulate
If your EPC rating is stuck in the D to G range, poor insulation is often to blame. Heat escapes through walls, roofs, and floors, forcing you to crank up the heating and your bills. Here’s how to stop those leaks:
Loft Insulation
Up to a quarter of your home’s heat can escape through an uninsulated roof. If your loft is bare or has thin, old insulation, topping it up to the recommended 270mm of mineral wool or similar is a game changer. It’s one of the cheapest and most effective ways to boost your EPC rating. For a typical semi detached house, expect to pay £300 to £600, saving £150 to £200 a year on energy bills. If you’re handy, you can do it yourself for less.
Wall Insulation
Most UK homes have cavity walls (two layers with a gap) or solid walls. Cavity wall insulation, where foam or beads are injected into the gap, is a must if your home was built between the 1920s and 1980s. It costs £500 to £1,500 but can reduce heat loss by up to 35%. For older homes with solid walls, external or internal insulation is pricier (£5,000 to £15,000) but highly effective for warmth and EPC points.
Floor Insulation
Don’t ignore your floors, especially if your ground floor feels chilly. Insulating under floorboards or adding insulation boards costs £1,000 to £2,000 but makes your home cosier and saves energy. Suspended wooden floors are particularly straightforward to insulate, just check if it’s already done.
Step 3: Upgrade Your Heating System
Your heating system heavily influences your EPC rating. If you’re stuck with an old boiler, it’s likely wasting energy. Here’s what to consider:
Swap to a Modern Boiler
Pre 2005 gas boilers can be as little as 60% efficient. A new condensing boiler, which recycles heat from exhaust gases, can reach 90% efficiency or more. It costs £1,500 to £3,500 including installation, but you could save £200 to £300 a year and significantly boost your EPC rating. Choose an A rated model and pair it with a smart thermostat for better control.
Consider a Heat Pump
For those ready to invest, air source or ground source heat pumps are eco friendly heating solutions. They use electricity to draw heat from the air or ground, slashing your carbon footprint. They cost £7,000 to £15,000, but government grants like the Boiler Upgrade Scheme can cover up to £7,500. Heat pumps work best in well insulated homes, so prioritise insulation first.
Add Heating Controls
Simple upgrades like thermostatic radiator valves (TRVs), a programmable thermostat, or a smart system like Hive or Nest can optimise your heating. These cost £100 to £500 and let you heat only the rooms you use, saving energy without losing comfort.
Step 4: Switch to Energy Efficient Lighting
This is an easy win. If you’re still using incandescent or halogen bulbs, switch to LEDs. They use up to 80% less energy and last years longer. Modern LEDs come in warm tones, so you won’t lose that cosy feel. Replacing all your bulbs might cost £50 to £100, but it’s a simple way to improve your EPC rating and lower your electricity bill.
Step 5: Upgrade Windows and Doors
Draughty windows and doors let heat escape. If your home has single glazing, upgrading to double or triple glazing can make a big difference. Double glazing costs £3,000 to £10,000 for a typical home but can save £100 to £200 a year and boost your EPC rating. If that’s too pricey, secondary glazing (adding a second pane inside existing windows) is a cheaper option.
Don’t overlook doors, a new, well sealed front door or insulating strips around existing ones can keep heat in. Look for doors with a high energy efficiency rating.
Step 6: Go Renewable with Solar Panels
Solar panels are a brilliant way to improve your EPC rating and cut energy costs long term. A typical 4kW system costs £5,000 to £8,000 and can generate half your electricity needs, depending on your home’s location and roof. You’ll also reduce your carbon footprint and might earn money by selling excess energy back to the grid via the Smart Export Guarantee. Solar panels are a significant investment but can push your EPC rating towards A or B.
Step 7: Small Changes, Big Impact
Not ready for major upgrades? Small tweaks can still help:
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Draught proofing: Seal gaps around windows, doors, and skirting boards with draught excluding tape or sealant. It’s cheap (under £50) and effective.
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Hot water tank insulation: If you have a hot water cylinder, a £20 insulating jacket keeps water hot longer.
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Low flow showerheads: These reduce water usage without compromising pressure, saving energy if you have an electric shower.
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Smart meters: These help you monitor energy use and identify wasteful habits.
Step 8: Check for Grants and Funding
Improving your EPC rating doesn’t have to be expensive. The UK government and local councils offer grants, especially for low income households or those in fuel poverty. Schemes like the Energy Company Obligation (ECO4), Boiler Upgrade Scheme, and Great British Insulation Scheme can cover insulation, heating upgrades, or solar panels.
Check with your energy supplier or visit gov.uk for eligibility. Some schemes depend on your location, benefits status, or current EPC rating, so do your research.
How Much Will It Improve Your Rating?
The impact depends on your starting point. A home at F or G could jump to D with good insulation and a new boiler. Combining several upgrades might get you to C or B. Reaching A is tougher, usually requiring a heat pump, solar panels, and top tier insulation, but even small changes can lower bills and improve comfort.
For example:
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Loft insulation: +5 to 10 EPC points
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Cavity wall insulation: +10 to 15 points
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New boiler: +10 to 20 points
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Double glazing: +5 to 10 points
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Solar panels: +10 to 15 points
Your EPC assessor can provide a more precise estimate based on your home.