Blown mineral wool insulation across West Sussex
We cover 9 towns in West Sussex, including Crawley, Worthing, Bognor Regis, Littlehampton, Horsham and more.
Exposure matters for every cavity wall. West Sussex has a mix of moderate and more exposed sites. Hilltop, coastal and west-facing walls take the brunt of wind-driven rain, so the survey records exposure for each elevation before a material is chosen.
Where a West Sussex property has an extension or a conservatory, we check how the old and new walls meet, because that junction is often missed. A suitable wall in West Sussex is usually filled in a single day from outside, with drill holes made good to match the pointing.
Building Regulations in England
Filling an existing cavity wall is notifiable building work in England. Either a building notice goes to building control before the work, or the installer self-certifies it through a government-approved competent person scheme such as CIGA's CWISC scheme. The insulation used must also be suitable for the wall it goes into, which is why the survey checks construction, condition and exposure first.
Funding in England
- ECO4, the energy-supplier scheme, has been extended to 31 December 2026 and government has said there will be no successor supplier obligation.
- The Great British Insulation Scheme closed as planned on 31 March 2026.
- Warm Homes: Local Grant supports low-income households in England through councils, and the January 2026 Warm Homes Plan sets out fully funded upgrades for low-income homes, with more detail still being published.
Sources: Planning Portal: cavity wall insulation and building regulations; CIGA: CWISC competent person scheme; GOV.UK: extending the ECO4 end date, government response; GOV.UK: Warm Homes Plan.
Why choose mineral wool?
Mineral wool fibres are treated to shed water, so moisture that gets into the outer leaf runs down the cavity rather than tracking across. It is classed as non-combustible, which matters for some flats and taller buildings, and it is usually the lower-cost certified option.
It is installed at a set density through a regular drill pattern. Too loose and it settles; too tight and it can bridge moisture. That is why the installer's density checks and hole pattern are recorded on the job sheet.
What is included
- Certified mineral fibre system
- Density and drill pattern recorded
- Making good to the mortar colour
- Cavity barriers where needed
- Regulations route and guarantee named on the quote
Blown mineral wool insulation prices in West Sussex
| Blown mineral wool insulation guide prices | Guide price |
|---|---|
| Detached house | £1,895–£3,395 |
| Semi-detached house | £1,295–£2,195 |
| End-terrace house | £1,095–£1,895 |
| Detached bungalow | £1,095–£1,895 |
| Semi-detached bungalow | £795–£1,395 |
| Mid-terrace house | £795–£1,295 |
No VAT is charged on installing insulation in homes until 31 March 2027 (then 5%). Guide ranges only: the fixed price is confirmed in writing before any work starts, and anything that could not be seen at survey is agreed with you first.
How it works in West Sussex:
Send your details
A minute online, or call the free number.
We check the walls
Construction, cavity width, debris, damp and wind-driven rain exposure.
You decide
Plain-English result and a fixed price, with no pressure to book.
Job done properly
Holes made good, paperwork handed over, guarantee details confirmed.