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Eltham · Greater London

Cavity insulation top-up in Eltham

Eltham homeowners, landlords and managing agents can book cavity insulation top-up with a free survey first. A cavity top-up fills voids left by an older installation: missed panels around windows, settled fibre, areas disturbed by an extension or new window.

Free survey in Eltham

Covering Eltham and the SE9 district. Tell us about the property and we will arrange a free survey and a fixed price.

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Cavity insulation top-up for Eltham properties

We cover Eltham and the SE9 postcode district, including nearby Blackheath, Welling and Catford. It is about 9 miles south-east of London.

Most Eltham houses built from the 1920s onwards have cavity walls, but the survey still checks each one: cavity width, debris, the condition of the brickwork and how exposed each wall is. For semi-detached and terraced homes in Eltham, cavity barriers are fitted where your wall meets your neighbour's so the fill stays on your side.

Before any material is chosen, exposure is checked. 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.

On the rules side, in Eltham 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.

How do I know if my walls need a top-up?

Cold patches on internal walls, a thermal image showing uneven heat loss, or an EPC that says 'filled cavity' when parts of the house feel colder are all signs. Extensions are a common cause: the new wall is insulated as built, but the old wall it joins may have been left partly empty.

What is included in Eltham

  • Map of filled and empty sections
  • Borescope survey at several points
  • Making good
  • Targeted fill with a compatible system

Guide prices for Eltham

Cavity insulation top-up guide prices
Cavity insulation top-up guide pricesGuide price
Detached house£1,295–£2,295
Semi-detached house£795–£1,495
End-terrace house£695–£1,295
Detached bungalow£695–£1,295
Semi-detached bungalow£595–£995
Mid-terrace house£595–£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.

How it works in Eltham:

  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 top-up in Eltham: questions

Is there VAT on cavity insulation top-up in Eltham?

Installing insulation in a home is currently zero-rated for VAT until 31 March 2027, then 5%. Commercial buildings are standard-rated.

Are there grants for insulation in Eltham?

In England, ECO4 runs to 31 December 2026 and Warm Homes: Local Grant supports low-income households through councils. We cannot promise funding, but we will point you to the right official route.

Do you cover Eltham?

Yes. Eltham and the SE9 postcode district are within our Greater London coverage, along with nearby Blackheath and Welling.

Is my Eltham home too exposed for cavity insulation?

Much of Greater London is in the more sheltered driving-rain zones, but exposed and coastal sites are still checked carefully. The survey records the exposure of each wall before recommending a material, or recommending against filling.

Nearby towns

Book a free survey in Eltham

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