Why Improve Your EPC Rating?
Improving your EPC rating isn't just about a letter on a certificate — it delivers real, tangible benefits that affect your wallet, your comfort, and the value of your home.
Lower energy bills: The most immediate benefit. A typical D-rated home spends around £1,400–£1,900 per year on energy. Moving to a C rating could save £400–£800 annually. Over 10 years, that's £4,000–£8,000 in your pocket.
Increased property value: Research shows each band improvement adds 1–3% to your property's value. For a £300,000 home, that's £3,000–£9,000 for moving from D to C.
Legal compliance: If you're a landlord, your property must meet a minimum EPC rating of E (and this may rise to C). See our landlord guide for details.
Comfort: Better insulation and heating means a warmer, more comfortable home with fewer draughts and more consistent temperatures.
Environmental impact: Reducing your home's energy consumption directly cuts carbon emissions, contributing to the UK's net-zero targets.
Quick Wins — Low-Cost Improvements
You don't need to spend thousands to make a difference. These low-cost measures can each add a few points to your EPC score:
LED Lighting (£50–£150 for whole house)
Replacing all traditional bulbs with LEDs is one of the simplest improvements. EPC assessors check your lighting, and a home with 100% LED lighting scores better than one with halogen or incandescent bulbs. LEDs use up to 90% less energy and last much longer.
Draught-Proofing (£100–£300)
Sealing gaps around doors, windows, letterboxes, and floorboards stops warm air escaping. Draught-proofing strips and covers are cheap and easy to install yourself. This won't dramatically change your EPC score on its own, but combined with other measures, it helps.
Hot Water Cylinder Insulation (£20–£50)
If you have a hot water tank, fitting a British Standard jacket (at least 80mm thick) significantly reduces heat loss. This is one of the cheapest energy improvements available. Many older homes still have uninsulated or poorly insulated cylinders.
Thermostatic Radiator Valves (£100–£250 installed)
TRVs let you control the temperature in individual rooms rather than heating the entire house to the same level. EPC assessors check for heating controls, and TRVs score well. You can install them yourself if you're handy, or get a plumber to fit them.
Heating Controls and Programmer (£100–£300)
Upgrading to a modern room thermostat with a timer/programmer allows you to heat your home only when needed. Smart thermostats like Hive, Nest, or Tado go further by learning your schedule and adjusting automatically. However, standard programmable thermostats score just as well on the EPC.
Insulation Upgrades — The Biggest Wins
Insulation is consistently the most impactful area for EPC improvements. Heat loss through walls, roofs, and floors accounts for the majority of energy waste in UK homes.
Loft Insulation (£300–£600)
If your loft insulation is below the recommended 270mm, topping it up is one of the best investments you can make. Many older homes have just 100mm or less. Going from 100mm to 270mm can improve your EPC score by 5–15 points.
This is often a DIY-friendly job if your loft is accessible. Rolls of mineral wool insulation are widely available at DIY stores. If your loft is hard to reach or you prefer professional installation, grants may cover the cost.
Cavity Wall Insulation (£500–£1,500)
If your home was built between the 1930s and 1990s, there's a good chance it has cavity walls that can be insulated by injecting material into the gap. This is one of the most cost-effective measures, potentially improving your score by 10–20 points.
A qualified installer drills small holes in the outer wall, injects insulation material (usually blown mineral wool or polystyrene beads), then seals the holes. The process usually takes half a day.
Solid Wall Insulation (£5,000–£15,000+)
Homes built before the 1930s typically have solid walls (no cavity). Insulating these is more expensive and invasive, but the impact on your EPC score is substantial — potentially 10–25 points. You have two options:
- Internal wall insulation: Fitting insulated boards to inside walls. Cheaper (£3,000–£8,000) but reduces room sizes slightly.
- External wall insulation: Cladding the outside of the building. More expensive (£8,000–£15,000+) but doesn't affect internal space and provides a fresh exterior finish.
Floor Insulation (£500–£2,000)
Suspended timber floors can be insulated from below (if there's access to a cellar or crawl space) or from above. Solid concrete floors can have insulation added on top before new flooring is laid. Floor insulation typically adds 3–8 points to your EPC score.
Heating System Improvements
Upgrading Your Boiler (£2,000–£4,500)
If your boiler is over 15 years old, it's likely an older model with an efficiency of 60–80%. A modern A-rated condensing boiler operates at 90%+ efficiency. This upgrade alone can improve your EPC score by 5–15 points and cut your heating bills by 20–30%.
Consider whether to replace like-for-like (gas with gas) or switch to a heat pump, which scores much higher on the EPC.
Air Source Heat Pump (£7,000–£14,000 before grants)
Heat pumps are the gold standard for EPC scores. An air source heat pump (ASHP) extracts heat from outdoor air and can deliver 3–4 units of heat for every unit of electricity used. They can dramatically improve your EPC rating, often by 15–30 points.
The Boiler Upgrade Scheme currently offers grants of up to £7,500 towards the cost of a heat pump, making this upgrade much more affordable. Heat pumps work best in well-insulated homes, so consider upgrading insulation first.
Smart Heating Controls (£150–£400)
Room-by-room heating control, weather compensation, and load compensation features all score well on the EPC. Smart thermostats with these features can add a few points to your score while also improving comfort and reducing waste.
Renewable Energy
Solar PV Panels (£5,000–£8,000 for 4kW system)
Solar panels are one of the most impactful additions for your EPC score. A 4kW system on a south-facing roof can improve your rating by 10–20 points. You'll also generate free electricity, earning back the investment through savings and the Smart Export Guarantee (SEG), which pays you for electricity exported to the grid.
Solar Thermal (Hot Water) (£3,000–£5,000)
Solar thermal panels heat water using sunlight. They're less common than PV panels but can contribute to your EPC score, particularly if you use a lot of hot water. They work best alongside a conventional boiler or heat pump.
Battery Storage (£3,000–£6,000)
While battery storage doesn't directly affect your EPC score (the current SAP methodology doesn't account for batteries), it maximises the benefit of solar panels by storing excess electricity for use in the evenings. It indirectly supports a lower-carbon lifestyle.
Windows and Doors
Double Glazing (£3,000–£8,000 for whole house)
Replacing single glazing with double glazing can improve your EPC score by 5–10 points. If you already have older double glazing (pre-2002), upgrading to modern A-rated double glazing will also help, though the improvement is smaller.
Triple Glazing (£5,000–£12,000)
Triple glazing offers superior insulation and noise reduction compared to double glazing. However, the additional EPC improvement over modern double glazing is modest — typically only 2–4 extra points. It's best considered as part of a comprehensive upgrade rather than a standalone measure.
Government Grants and Funding
Several government schemes can help fund energy efficiency improvements:
- Great British Insulation Scheme: Covers cavity wall, loft, and solid wall insulation for eligible households (based on council tax band and energy supplier). Check eligibility on Great British Energy →
- Boiler Upgrade Scheme (BUS): Grants of up to £7,500 for air source heat pumps and £7,500 for ground source heat pumps. Available until March 2028.
- ECO4 (Energy Company Obligation): Energy suppliers fund improvements for low-income and fuel-poor households. Covers insulation, heating, and more.
- Home Upgrade Grant (HUG2): For off-gas-grid homes in England with EPC ratings of D, E, F, or G. Provides up to £10,000 for energy efficiency measures.
- Local authority grants: Many councils offer their own schemes. Check with your local authority for what's available in your area.
Check What Grants You're Eligible For
Government funding could cover some or all of your improvement costs.
Check Grant Eligibility →Prioritising Your Improvements
With limited budget, prioritise improvements that deliver the best return. Here's a rough guide ranked by cost-effectiveness:
| Improvement | Cost | EPC Impact | Annual Saving |
|---|---|---|---|
| Loft insulation top-up | £300–£600 | 5–15 pts | £100–£250 |
| LED lighting | £50–£150 | 1–5 pts | £30–£80 |
| Cavity wall insulation | £500–£1,500 | 10–20 pts | £150–£300 |
| Boiler upgrade | £2,000–£4,500 | 5–15 pts | £200–£400 |
| Solar PV (4kW) | £5,000–£8,000 | 10–20 pts | £300–£600 |
| Heat pump | £7,000–£14,000 | 15–30 pts | £300–£600 |
| Double glazing | £3,000–£8,000 | 5–10 pts | £100–£200 |
| Solid wall insulation | £5,000–£15,000 | 10–25 pts | £200–£500 |
Start with the cheapest and highest-impact measures first. Your existing EPC report will include specific recommendations tailored to your property — follow those for the most accurate guidance.
Getting Reassessed
After making improvements, you'll need a new EPC assessment to get your updated rating. Here's what to know:
- Keep evidence: Have invoices, certificates, and product specifications ready for the assessor. This helps them accurately record what's been installed.
- Ensure work is visible: If insulation is hidden (e.g. cavity wall), have the guarantee certificate from the installer.
- Book a good assessor: A thorough assessor who takes time to check everything will give you a more accurate (and likely better) rating than one who rushes.
- Time it right: Get your new EPC after all improvements are complete, not partway through.