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Cornwall · England

Cavity wall insulation for flats in Cornwall

Flats share their outer walls, so cavity wall insulation is normally done for the whole block at once with the freeholder's agreement. Our Cornwall coverage includes Truro, Falmouth, St Austell and the towns around them.

Three-storey 1960s red brick block of flats

Free survey in Cornwall

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 wall insulation for flats across Cornwall

We cover 8 towns in Cornwall, including Redruth, Falmouth, St Austell, Truro, Camborne and more.

Every elevation is judged on its own exposure. Parts of Cornwall face some of the heaviest wind-driven rain in the UK, especially exposed coastal and upland sites. Here the survey is stricter: some walls suit only certain certified systems, and some should not be filled at all.

Work on Cornwall rented homes and blocks is booked around tenants and residents, with access arranged through your agent if you prefer. Blocks of flats in Cornwall 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.

Fire and height

For blocks, the material must suit the building's height and use. Non-combustible mineral wool is the usual choice; we confirm the system and its certificate limits in writing.

What is included

  • Block survey
  • Freeholder and agent coordination
  • Leaseholder information sheet
  • Per-flat pricing

Cavity wall insulation for flats prices in Cornwall

Cavity wall insulation for flats guide prices
Cavity wall insulation for flats guide pricesGuide 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 Cornwall:

  1. Tell us about the property

    Postcode, property type and what you need.

  2. Free survey

    Walls, cavity, condition and exposure checked and photographed.

  3. Written result and price

    Suitable, suitable after repairs, or not suitable, with a fixed price.

  4. Work and paperwork

    Installation, making good, and the regulations and guarantee paperwork.

Last reviewed 19 October 2026.

Cavity wall insulation for flats in Cornwall: questions

Do you cover all of Cornwall?

Yes. We cover 8 towns across Cornwall, including Redruth, Falmouth, St Austell and Truro, and the villages around them. Island and remote addresses are surveyed by arrangement.

How much does cavity wall insulation for flats cost in Cornwall?

Our guide ranges for cavity wall insulation for flats are shown on this page. The fixed price for your Cornwall property is confirmed in writing after the survey, before any work starts.

Is the survey free in Cornwall?

Yes when it is for an install quote. Standalone reports for Cornwall buyers, sellers or landlords who do not need an install quote are priced before you book.

Do you cold-call in Cornwall?

No. We only come out when you have asked us to. If someone cold-calls offering free insulation, check before you agree to anything.

Cavity wall insulation for flats in nearby areas

Book a free survey in Cornwall

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