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Brecon · Powys

Cavity insulation for new builds and extensions in Brecon

For homes and buildings in Brecon, cavity insulation for new builds and extensions is arranged survey-first: we check the property, tell you plainly what we found, and price it. 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 Brecon

Covering Brecon and the LD3 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 Brecon properties

Brecon is among the towns we cover in Powys, alongside Llandrindod Wells and Newtown. It is roughly 39 miles south of Newtown.

Most Brecon 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 Brecon, 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. Parts of Powys 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.

As for paperwork, in Brecon 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 Brecon

  • Clean-cavity working
  • Trays, closers and stop ends as drawn
  • Batts or boards to the specified U-value
  • Photo record for building control

Guide prices for Brecon

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 Brecon:

  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 Brecon: questions

Do you cover Brecon?

Yes. Brecon and the LD3 postcode district are within our Powys coverage, along with nearby Llandrindod Wells and Newtown.

Which building regulations route applies in Brecon?

Brecon 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.

How soon can you visit in Brecon?

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.

Do you cold-call in Brecon?

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

Nearby towns

Book a free survey in Brecon

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