Cavity insulation for new builds and extensions across County Londonderry
We cover 4 towns in County Londonderry: Derry, Coleraine, Limavady and Magherafelt.
Every elevation is judged on its own exposure. 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.
County Londonderry 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 County Londonderry, cavity barriers are fitted where your wall meets your neighbour's so the fill stays on your side.
Building control in Northern Ireland
In Northern Ireland, inserting insulation into an existing cavity wall needs a building control application to your council before the work. We make sure the application route is agreed and confirmed in writing before any drilling starts.
Funding in Northern Ireland
- The Affordable Warmth Scheme, run with the NI Housing Executive, helps owner-occupiers and private tenants with a total gross household income under £23,000; cavity wall insulation is a priority measure where suitable.
- The NI Sustainable Energy Programme funds energy efficiency schemes through participating providers.
- ECO4 does not apply in Northern Ireland.
Sources: Building Control NI: frequently asked questions; Belfast City Council: what are the building regulations; 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
- Batts or boards to the specified U-value
- Clean-cavity working
- Trays, closers and stop ends as drawn
- Coordination with your bricklayers
- Photo record for building control
Cavity insulation for new builds and extensions prices in County Londonderry
| Cavity insulation for new builds and extensions guide prices | Guide 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.
What happens next for a County Londonderry property:
Send your details
A minute online, or call the free number.
We check the walls
Construction, cavity width, debris, damp and wind-driven rain exposure.
You decide
Plain-English result and a fixed price, with no pressure to book.
Job done properly
Holes made good, paperwork handed over, guarantee details confirmed.