Cavity Wall Insulation Cost & Grants
How much does cavity wall insulation cost, what does removal cost, and can you get a grant? This guide explains what drives the price, typical UK figures and the funding schemes open at the time of writing (November 2026). For an exact figure, Proofterior give a fixed written quote after a complimentary survey anywhere in Dorset, Hampshire and Wiltshire.
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Genuine reviews from local homeowners
Over 200 verified reviews across Checkatrade, Google and Yell
“Excellent service from start to finish. The survey was thorough and professional, with honest, evidence-based advice rather than trying to sell unnecessary work. I came away with complete peace of mind.”
Alex Richards-Taylor
Google review
“Excellent service throughout. Ashton came out to look at an issue raised on a part-exchange survey and, rather than recommend expensive remediation, told me honestly there was nothing wrong with the wall. Great to have an honest discussion.”
Ian M.
BH16 · Damp Investigation
“Dylan and the Proofterior team were amazing. The report was incredibly comprehensive. Can’t recommend them enough.”
Sam Short
Google review
“Very pleased with the work on our living room and bedroom walls. Punctual, polite and friendly, and completed on time even though it was Easter week. Many thanks to everyone at Proofterior.”
Chris G.
BH20 · Penetrating Damp Treatment
“Dan was very thorough, professional and polite. Quick to respond and I would highly recommend.”
Malik R.
Yell · Quick & Professional
“The workmen were clean, pleasant and efficient and took just one day. The very next day we noticed a big difference with the damp issue. Many thanks.”
Nick Bennett
Google review
“Able to fit my job in for the next day and completed in a day as agreed. Not the lowest quote, but it comes with a 25-year guarantee, which I wanted — long-term peace of mind was vital.”
Alan M.
BH23 · Flat Roof Reseal
“Ashton was so friendly and informative. I’ve gone from worried to empowered — someone you can trust to do the right thing.”
Suzanna Furbank
Google review
“Really amazing service. Dan provided a really thorough damp investigation and a very helpful damp report. Very quick responses too.”
Paul A.
Yell · Damp Investigation
“Happy with the speed — a full flat survey within a week. They explained our options, the price was extremely competitive, and our tenants are pleased with their fresher, safer flat.”
Verified Customer
SP6 · Damp Proofer
“Dan provided a very professional service from start to finish. Very good communication and a first-class job.”
Mark H.
Yell · Professional Service
“Excellent service from start to finish. The survey was thorough and professional, with honest, evidence-based advice rather than trying to sell unnecessary work. I came away with complete peace of mind.”
Alex Richards-Taylor
Google review
“Excellent service throughout. Ashton came out to look at an issue raised on a part-exchange survey and, rather than recommend expensive remediation, told me honestly there was nothing wrong with the wall. Great to have an honest discussion.”
Ian M.
BH16 · Damp Investigation
“Dylan and the Proofterior team were amazing. The report was incredibly comprehensive. Can’t recommend them enough.”
Sam Short
Google review
“Very pleased with the work on our living room and bedroom walls. Punctual, polite and friendly, and completed on time even though it was Easter week. Many thanks to everyone at Proofterior.”
Chris G.
BH20 · Penetrating Damp Treatment
“Dan was very thorough, professional and polite. Quick to respond and I would highly recommend.”
Malik R.
Yell · Quick & Professional
“The workmen were clean, pleasant and efficient and took just one day. The very next day we noticed a big difference with the damp issue. Many thanks.”
Nick Bennett
Google review
“Able to fit my job in for the next day and completed in a day as agreed. Not the lowest quote, but it comes with a 25-year guarantee, which I wanted — long-term peace of mind was vital.”
Alan M.
BH23 · Flat Roof Reseal
“Ashton was so friendly and informative. I’ve gone from worried to empowered — someone you can trust to do the right thing.”
Suzanna Furbank
Google review
“Really amazing service. Dan provided a really thorough damp investigation and a very helpful damp report. Very quick responses too.”
Paul A.
Yell · Damp Investigation
“Happy with the speed — a full flat survey within a week. They explained our options, the price was extremely competitive, and our tenants are pleased with their fresher, safer flat.”
Verified Customer
SP6 · Damp Proofer
“Dan provided a very professional service from start to finish. Very good communication and a first-class job.”
Mark H.
Yell · Professional Service
What is Cavity Wall Insulation Cost & Grants?
Cavity wall insulation cost depends mainly on the area of wall, the insulation material, access and any repairs needed first. As typical UK guide figures, installation ranges from roughly £400 for a small flat to around £5,000 for a large detached house, with a three-bedroom semi commonly around £900 to £2,500. Material choice matters: mineral wool is usually cheapest, bonded EPS beads sit in the middle, and polyurethane foam costs most. Cavity wall insulation removal typically costs more than installing, often around £900 to £2,000 for a standard house, and more for foam or difficult access. On grants: the Great British Insulation Scheme closed on 31 March 2026, ECO4 is due to close on 31 December 2026, and the Warm Homes: Local Grant (England) is available through participating councils to March 2028 for eligible lower-income households in homes rated EPC D to G. Grant-funded measures are free to eligible households, so be wary of anyone charging an application fee. Scheme rules change, so always check GOV.UK or your council.
The warning signs to look for
Catching the problem early keeps repairs simpler and less costly. If you notice any of these signs, it is worth booking a specialist survey before the damage spreads.
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- Wall area and number of elevations
- Insulation material: mineral wool, bonded beads or foam
- Access, scaffolding and height of the building
- Repairs needed first: pointing, render, gutters
- For removal: type and condition of the existing fill
- Debris or bridging that needs clearing from the cavity
- Re-insulation after removal
- Internal making good, mould treatment or re-plastering
Our treatment process
Every job follows the same careful, diagnosis-first method — so you know exactly what is happening and why at each stage.
Complimentary survey: we check the walls, the cavity and any existing insulation.
Clear options: we explain what the wall needs, and what it does not.
Fixed written quote: itemised, so you can see exactly what you are paying for.
Grant signposting: if you may be eligible for funding, we point you to the right scheme first.
Works: carried out by our vetted, Proofterior-trained team on an agreed date.
Guarantee: our 25-year insured guarantee and flexible finance options on eligible work.
Cavity Wall Insulation Cost & Grants — from our recent projects
Real photos from Proofterior jobs across Dorset, Hampshire and Wiltshire — carried out by our own in-house team.
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Diagnosis first
We identify the real cause before recommending any treatment. No guesswork, and never unnecessary work.
In-house specialist team
Vetted, Proofterior-trained specialists, managed by us from survey to completion. No compromises.
25-year guarantee
Every treatment is backed by our 25-year insured guarantee, giving you lasting protection and peace of mind.
Cavity Wall Insulation Cost & Grants across Bournemouth, Poole & the South Coast
Prices in Dorset, Hampshire and Wiltshire are broadly in line with the UK figures above. Exposed coastal homes in Bournemouth, Poole, Christchurch and Southsea are more likely to need repairs or a bead fill rather than mineral wool, while sheltered inland homes in Salisbury, Winchester and Andover are often more straightforward. Some councils in our area take part in the Warm Homes: Local Grant, so check your council website. Our team works across Bournemouth, Poole, Christchurch, Southampton, Portsmouth, Winchester, Salisbury and the towns and villages in between.
Covering Dorset, Hampshire & Wiltshire
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Everything you might be wondering
As typical UK guide figures, roughly £400 to £5,000 depending on property size and material, with a three-bed semi commonly around £900 to £2,500. Your actual price depends on your walls, so we give a fixed quote after the survey.
Typically around £900 to £2,000 for a standard house, more for large properties, scaffolding or foam insulation. Re-insulation and repairs are quoted separately so you can see each part.
Possibly. At the time of writing, ECO4 is due to close on 31 December 2026 and the Warm Homes: Local Grant runs through participating councils in England to March 2028 for eligible lower-income households in EPC D to G homes. The Great British Insulation Scheme closed in March 2026. Check GOV.UK or your council for current rules.
Grants generally fund new insulation rather than removal. If failed insulation is covered by a guarantee, the installer or CIGA route may cover remedial work instead.
Genuine grant-funded measures are free to eligible households. The warning signs are cold calls, pressure to sign on the day, or any request for an application or admin fee. Check the scheme on GOV.UK before agreeing to anything.
Yes. Flexible finance is available on eligible works, so you can spread the cost. Ask during your survey or see our finance page.
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