If you’re a UK homeowner, cutting down on your energy bills while keeping your home warm is always a smart move — and cavity wall insulation can help you do just that. Even better, government grants and schemes are available in 2025 that could cover part or even all of the installation costs.
In this guide, we’ll break down cavity wall insulation grants, typical cavity wall insulation cost, the benefits of getting your walls insulated, and how to check if you qualify for free cavity wall insulation in the UK.
What Is Cavity Wall Insulation?
Cavity wall insulation involves filling the gap (or ‘cavity’) between your home’s external and internal walls with insulating material. This prevents heat from escaping, keeping your home warmer in winter and cooler in summer.
Most homes built after the 1920s have cavity walls, and if your property isn’t already insulated, you could be wasting up to 35% of your heating through uninsulated walls.
The Benefits of Cavity Wall Insulation
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Lower Energy Bills: Proper insulation means your heating system works less, saving you money.
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Warmer Home: A consistent, comfortable indoor temperature.
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Reduced Carbon Footprint: Less energy consumption means fewer carbon emissions.
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Increased Property Value: Energy-efficient homes tend to attract buyers.
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Quick Installation: Most installations take just a few hours.
Cavity Wall Insulation Cost in 2025
So, how much does cavity wall insulation cost in 2025? Prices can vary based on property size, location, and the type of insulation material used.
Note: These are rough estimates — actual costs depend on the installer and your property’s specifications.
What Are Cavity Wall Insulation Grants?
Government grants for wall insulation are part of the UK’s effort to reduce household carbon emissions and help homeowners cut energy costs. In 2025, several schemes are offering free cavity wall insulation UK-wide, or substantial discounts depending on eligibility.
Who Is Eligible for Free Cavity Wall Insulation in the UK?
You might qualify for free cavity wall insulation or a heavily subsidised installation if:
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You own or privately rent your home.
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Your property was built after the 1920s and has uninsulated cavity walls.
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You or someone in your household receives certain benefits (like Universal Credit, Pension Credit, or Income Support).
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Your home meets certain energy efficiency criteria (typically an EPC rating of D or lower).
Even if you don’t receive benefits, some schemes offer partial grants for homes in certain areas or for properties with poor insulation.
How to Apply for Cavity Wall Insulation Grants
Applying for a grant is straightforward:
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Check Eligibility: Use an online eligibility checker or contact a registered installer.
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Arrange a Survey: An assessor will visit your home to confirm suitability.
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Get a Quote or Approval: If eligible, you’ll receive confirmation and installation will be scheduled.
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Installation Day: Most jobs are completed within a few hours with minimal disruption.
Available Government Schemes in 2025
Several initiatives are currently active:
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Energy Company Obligation (ECO4 Scheme): The UK’s flagship energy efficiency scheme providing free or discounted insulation for eligible households.
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Great British Insulation Scheme (GBIS): Aimed at middle-income and vulnerable households, offering grants for cavity wall, loft, and solid wall insulation.
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Local Authority Delivery (LAD): Grants distributed by local councils, especially for homes with low energy performance.
Potential Savings from Cavity Wall Insulation
According to the Energy Saving Trust, a typical 3-bedroom semi-detached house could save around £255 per year on energy bills after cavity wall insulation.
Over time, these savings can quickly cover the upfront costs (if any), while improving your home’s comfort and energy efficiency.
Is Cavity Wall Insulation Worth It in 2025?
Absolutely. With rising energy prices and growing environmental concerns, making your home more energy-efficient is both a financial and ethical investment. The availability of cavity wall insulation grants in 2025 makes it even more appealing for homeowners looking to reduce their bills and carbon footprint.
FAQs
How much does cavity wall insulation cost in the UK?
In 2025, prices range from £400 to £1,400, depending on property size and insulation type — but grants could reduce this to zero for eligible homes.
Can I get free cavity wall insulation in the UK?
Yes — if you meet certain criteria, including receiving qualifying benefits or having a low EPC rating, you could qualify for free cavity wall insulation through government-backed schemes like ECO4.
How long does cavity wall insulation last?
Modern cavity wall insulation typically lasts 25 years or more, often with a guarantee from the installer.
Do I need planning permission for cavity wall insulation?
No — in most cases, it falls under permitted development. However, if your property is listed or in a conservation area, you might need to check with your local council.
How do I apply for government grants for wall insulation?
You can apply through an approved installer or check eligibility on a grant provider’s website. They’ll arrange a free assessment and handle the paperwork if you qualify.
Final Thoughts
Cavity wall insulation remains one of the most effective ways to improve your home’s energy efficiency in 2025 — and thanks to government grants for wall insulation, it’s more accessible than ever.
If you haven’t checked your eligibility yet, now’s the perfect time to take advantage of the schemes available and start saving on your energy bills.
Cavity Grant 
