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Southampton · Hampshire

Cavity insulation top-up in Southampton

From the first survey to the paperwork, cavity insulation top-up in Southampton is handled by one team and one contract. 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 Southampton

Covering Southampton and the SO14 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 Southampton properties

Southampton sits in Hampshire. We work across the SO14 district, including nearby Hythe, Totton and Eastleigh.

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

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

On compliance, in Southampton 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 Southampton

  • Written result with photos
  • Targeted fill with a compatible system
  • Borescope survey at several points
  • Making good

Guide prices for Southampton

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.

From enquiry to finish in Southampton:

  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 insulation top-up in Southampton: questions

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

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

Do you cover Southampton?

Yes. Southampton and the SO14 postcode district are within our Hampshire coverage, along with nearby Hythe and Totton.

How soon can you visit in Southampton?

We arrange dates when you get in touch. Availability varies through the year, so we give you real dates rather than a promise on the website.

Which building regulations route applies in Southampton?

Southampton is in England, so filling a cavity is notifiable building work and needs a building notice or competent-person self-certification. We confirm the route in writing on your quote.

Nearby towns

Book a free survey in Southampton

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