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Thamesmead · Greater London

Cavity insulation for new builds and extensions in Thamesmead

Thamesmead homeowners, landlords and managing agents can book cavity insulation for new builds and extensions with a free survey first. 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 Thamesmead

Covering Thamesmead and the SE28 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 Thamesmead properties

We cover Thamesmead and the SE28 postcode district, including nearby Barking, Welling and Becontree. It is roughly 11 miles east of London.

For semi-detached and terraced homes in Thamesmead, cavity barriers are fitted where your wall meets your neighbour's so the fill stays on your side. Thamesmead properties with rendered or painted walls get a closer look at the outer finish, because cracked render can let rain behind it.

Every elevation is judged on its own exposure. Much of Greater London sits in the more sheltered driving-rain zones of the UK, which widens the choice of fill. Exposed elevations, coastal sites and high ground still get checked wall by wall.

In terms of approvals, in Thamesmead 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.

What we work from

Your architect's or designer's specification and the energy calculation for the job. We match the product, thickness and fixing to that spec, keep cavities clean as the walls rise, and fit cavity trays, closers and stop ends where shown so the building control inspection goes smoothly.

What is included in Thamesmead

  • Trays, closers and stop ends as drawn
  • Coordination with your bricklayers
  • Batts or boards to the specified U-value
  • Clean-cavity working

Guide prices for Thamesmead

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.

How it works in Thamesmead:

  1. Get in touch

    Online, by phone or WhatsApp, whichever suits you.

  2. Survey visit

    The surveyor checks each wall and looks into the cavity where needed.

  3. Your result in writing

    What we found, what it means, and a fixed price if work is needed.

  4. Booked work

    Carried out by the installer named on your quote, with their scheme registrations.

Last reviewed 19 October 2026.

Cavity insulation for new builds and extensions in Thamesmead: questions

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

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 Thamesmead?

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

Do you cold-call in Thamesmead?

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

Do you cover Thamesmead?

Yes. Thamesmead and the SE28 postcode district are within our Greater London coverage, along with nearby Barking and Welling.

Nearby towns

Book a free survey in Thamesmead

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