Underfloor insulation across West Sussex
We cover 9 towns in West Sussex, including Crawley, Worthing, Bognor Regis, Littlehampton, Horsham and more.
In West Sussex homes this is often done on the same visit as a cavity fill, which saves a second trip. We check ventilation as carefully as insulation in West Sussex homes, because both matter for keeping a house dry.
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.
Keeping the void ventilated
Air bricks under a suspended floor must stay clear so the timbers stay dry. Insulation goes between the joists, not across the void, and gaps at skirtings are sealed to stop draughts.
What is included
- Floor void inspection
- Insulation between joists
- Draught sealing at skirtings
- Boards relaid
Underfloor insulation prices in West Sussex
| Underfloor insulation guide prices | Guide price |
|---|---|
| Suspended timber floor, typical room | £795–£1,495 |
| Whole ground floor | £1,995–£3,995 |
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.
What happens next for a West Sussex property:
Tell us about the property
Postcode, property type and what you would like done.
Free survey
Access, condition, existing insulation and ventilation checked.
Written result and price
What we recommend and a fixed price before any work.
Work and tidy-up
Fitted at an agreed time, with ventilation kept clear.