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Magherafelt · County Londonderry

Cavity insulation for new builds and extensions in Magherafelt

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. We cover Magherafelt and the wider BT45 postcode district, with the survey, result and fixed price all in writing.

Free survey in Magherafelt

Covering Magherafelt and the BT45 district. Tell us about the property and we will arrange a free survey and a fixed price.

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Cavity insulation for new builds and extensions for Magherafelt properties

Magherafelt is among the towns we cover in County Londonderry, alongside Limavady, Coleraine and Derry. It is roughly 31 miles south-east of Derry.

Most Magherafelt 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 Magherafelt, cavity barriers are fitted where your wall meets your neighbour's so the fill stays on your side.

Exposure matters for every cavity wall. Parts of County Londonderry 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 Magherafelt inserting cavity wall insulation needs a building control application to the council before work starts.

Funding in Northern Ireland

In Northern Ireland, the Affordable Warmth Scheme helps eligible households with a gross income under £23,000.

Sources: NI Housing Executive: Affordable Warmth Scheme; Utility Regulator: NI Sustainable Energy Programme.

Extensions that join an older house

Where an extension meets an existing cavity wall, the junction is a weak point. We can borescope and fill the existing wall at the same time so the old and new walls perform together.

What is included in Magherafelt

  • Coordination with your bricklayers
  • Clean-cavity working
  • Photo record for building control
  • Trays, closers and stop ends as drawn

Guide prices for Magherafelt

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.

The steps for cavity insulation for new builds and extensions in Magherafelt:

  1. Send your details

    A minute online, or call the free number.

  2. We check the walls

    Construction, cavity width, debris, damp and wind-driven rain exposure.

  3. You decide

    Plain-English result and a fixed price, with no pressure to book.

  4. Job done properly

    Holes made good, paperwork handed over, guarantee details confirmed.

Last reviewed 19 October 2026.

Cavity insulation for new builds and extensions in Magherafelt: questions

Which building regulations route applies in Magherafelt?

Magherafelt is in Northern Ireland, so inserting cavity wall insulation needs a building control application to the council before work starts. We confirm the route in writing on your quote.

Are there grants for insulation in Magherafelt?

In Northern Ireland, the Affordable Warmth Scheme helps eligible households with a gross income under £23,000. We cannot promise funding, but we will point you to the right official route.

Is the survey free in Magherafelt?

Yes when it is for an install quote. Standalone reports for Magherafelt buyers, sellers or landlords who do not need an install quote are priced before you book.

Is my Magherafelt home too exposed for cavity insulation?

Parts of County Londonderry 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.

Nearby towns

Book a free survey in Magherafelt

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