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Holyhead · Gwynedd

Cavity insulation for new builds and extensions in Holyhead

Holyhead 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 Holyhead

Covering Holyhead and the LL65 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 Holyhead properties

If your property is in Holyhead or the LL65 district or nearby Caernarfon and Bangor, it is within our Gwynedd coverage. It is about 20 miles west of Bangor.

Holyhead properties with rendered or painted walls get a closer look at the outer finish, because cracked render can let rain behind it. If a wall in Holyhead is not suitable, for example because of an undiagnosed damp patch or a very exposed gable, you are told so in writing with the reason.

Wind-driven rain is the first thing the surveyor weighs up. Parts of Gwynedd 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.

In terms of approvals, in Holyhead filling a cavity is notifiable work under the Building Regulations as they apply in Wales, usually self-certified through a competent person scheme.

Funding in Wales

In Wales, Warm Homes Nest offers free improvements to eligible low-income households, and ECO4 runs to 31 December 2026.

Sources: Welsh Government: warmer and more energy efficient homes (July 2026); GOV.UK: extending the ECO4 end date, government response.

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 Holyhead

  • Batts or boards to the specified U-value
  • Photo record for building control
  • Trays, closers and stop ends as drawn
  • Coordination with your bricklayers

Guide prices for Holyhead

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.

From enquiry to finish in Holyhead:

  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 for new builds and extensions in Holyhead: questions

Do you work on rented homes in Holyhead?

Yes. Landlords and agents in Holyhead can book batch visits, and work is arranged around tenants.

Do you cold-call in Holyhead?

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

Which building regulations route applies in Holyhead?

Holyhead is in Wales, so filling a cavity is notifiable work under the Building Regulations as they apply in Wales, usually self-certified through a competent person scheme. We confirm the route in writing on your quote.

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

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.

Nearby towns

Book a free survey in Holyhead

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