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Dyfed · Wales

Cavity insulation top-up in Dyfed

Cavity insulation top-up across Dyfed, survey-first: a written result for every wall and a fixed price before work. 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.

Technician inserting a borescope camera probe into a small hole in a buff brick wall

Free survey in Dyfed

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 top-up across Dyfed

We cover 6 towns in Dyfed, including Llanelli, Ammanford, Carmarthen, Aberystwyth, Haverfordwest and more.

Exposure matters for every cavity wall. Parts of Dyfed 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.

Dyfed properties with rendered or painted walls get a closer look at the outer finish, because cracked render can let rain behind it. Most Dyfed 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.

Building Regulations in Wales

In Wales, filling an existing cavity is also notifiable building work under the Building Regulations as they apply in Wales. A registered installer normally self-certifies it through a competent person scheme; otherwise a building notice goes to your council's building control before work starts. Welsh rules can differ from England's, so the notification route is confirmed in writing on your quote.

Funding in Wales

  • Warm Homes Nest offers free improvements, including insulation, to eligible low-income owner-occupiers and private renters; eligibility was widened to some households without means-tested benefits.
  • Green Homes Wales has been piloting advice and interest-free loans for households above the Nest and ECO4 income thresholds.
  • ECO4 runs until 31 December 2026 across Great Britain, including Wales.

Sources: Welsh Government: building work competent person schemes; CIGA: CWISC competent person scheme; Welsh Government: issues arising from cavity wall insulation installations; Welsh Government: warmer and more energy efficient homes (July 2026); GOV.UK: extending the ECO4 end date, government response.

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

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

Cavity insulation top-up prices in Dyfed

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 Dyfed:

  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 Dyfed: questions

Do you cover all of Dyfed?

Yes. We cover 6 towns across Dyfed, including Llanelli, Ammanford, Carmarthen and Aberystwyth, and the villages around them. Island and remote addresses are surveyed by arrangement.

Is my Dyfed home too exposed for cavity insulation?

Parts of Dyfed get some of the heaviest wind-driven rain in the UK, so the survey is stricter and some walls are better left unfilled. The survey records the exposure of each wall before recommending a material, or recommending against filling.

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

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

Do you cold-call in Dyfed?

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 insulation top-up in nearby areas

Book a free survey in Dyfed

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