Cavity wall insulation for flats 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.
For landlords and managing agents in West Sussex, we survey in batches and return a result sheet and fixed price per address. Blocks of flats in West Sussex are surveyed as a whole, because the cavity runs across every flat in the building.
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 one flat cannot usually be done alone
The cavity runs continuously across the building. The Energy Saving Trust notes that flats need agreement from the whole block. Filling one flat's walls in isolation leaves gaps, and the freeholder normally owns the structure.
What is included
- Block survey
- Freeholder and agent coordination
- Leaseholder information sheet
- Per-flat pricing
Cavity wall insulation for flats prices in West Sussex
| Cavity wall insulation for flats guide prices | Guide price |
|---|---|
| Per flat, whole-block fill (low-rise) | £495–£995 |
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.
From enquiry to finish 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.