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Brighton · East Sussex

Cavity insulation for new builds and extensions in Brighton

Cavity insulation for new builds and extensions in Brighton starts with a free survey of the property, then a written result and a fixed price before any work is booked. For new walls the cavity is insulated as it is built, using full-fill mineral wool batts or partial-fill boards fixed to the inner leaf.

Free survey in Brighton

Covering Brighton and the BN1 district. Tell us about the property and we will arrange a free survey and a fixed price.

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We use your details only to answer this enquiry and arrange your visit, sharing them only with the registered installer we appoint for your job and the providers named in our privacy notice. No marketing lists, no cold calls.

Cavity insulation for new builds and extensions for Brighton properties

Brighton sits in East Sussex. We work across the BN1 district, including nearby Hove, Rottingdean and Seaford.

For semi-detached and terraced homes in Brighton, cavity barriers are fitted where your wall meets your neighbour's so the fill stays on your side. Where a Brighton property has an extension or a conservatory, we check how the old and new walls meet, because that junction is often missed.

Wind-driven rain is the first thing the surveyor weighs up. East 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.

As for paperwork, in Brighton filling a cavity is notifiable building work and needs a building notice or competent-person self-certification.

Funding in England

In England, ECO4 runs to 31 December 2026 and Warm Homes: Local Grant supports low-income households through councils.

Sources: GOV.UK: extending the ECO4 end date, government response; GOV.UK: Warm Homes Plan.

Extensions that join an older house

Where an extension meets an existing cavity wall, the junction is a weak point. We can borescope and fill the existing wall at the same time so the old and new walls perform together.

What is included in Brighton

  • Photo record for building control
  • Coordination with your bricklayers
  • Batts or boards to the specified U-value
  • Trays, closers and stop ends as drawn

Guide prices for Brighton

Cavity insulation for new builds and extensions guide prices
Cavity insulation for new builds and extensions guide pricesGuide price
Full-fill batts supplied and fitted, per m²£9–£16
Partial-fill boards supplied and fitted, per m²£14–£26

Prices are shown before any VAT; the VAT treatment for new-build work is confirmed on your quote. 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 Brighton:

  1. Send your details

    A minute online, or call the free number.

  2. We check the walls

    Construction, cavity width, debris, damp and wind-driven rain exposure.

  3. You decide

    Plain-English result and a fixed price, with no pressure to book.

  4. Job done properly

    Holes made good, paperwork handed over, guarantee details confirmed.

Last reviewed 19 October 2026.

Cavity insulation for new builds and extensions in Brighton: questions

Is there VAT on cavity insulation for new builds and extensions in Brighton?

Building a new home is usually zero-rated when supplied by the builder; supply-only materials are standard-rated. The VAT treatment is confirmed on your quote.

How much does cavity insulation for new builds and extensions cost in Brighton?

Our guide ranges for cavity insulation for new builds and extensions are shown on this page. The fixed price for your Brighton property is confirmed in writing after the survey, before any work starts.

Do you work on rented homes in Brighton?

Yes. Landlords and agents in Brighton can book batch visits, and work is arranged around tenants.

Is my Brighton home too exposed for cavity insulation?

East Sussex has a mix of moderate and more exposed sites, so each wall is judged on its own. The survey records the exposure of each wall before recommending a material, or recommending against filling.

Nearby towns

Book a free survey in Brighton

Free survey with an install quote. Written result. Fixed price before any work.