Party wall cavity insulation 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.
A suitable wall in County Londonderry is usually filled in a single day from outside, with drill holes made good to match the pointing. If a wall in County Londonderry 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.
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.
What we need from you and your neighbour
The cavity is shared, so we talk you through notifying your neighbour before work. Filling is done from your side, usually through the loft. The survey confirms the wall is a cavity wall and not solid masonry, and checks for cables, flues and any gaps that would let fill escape.
What is included
- Loft inspection and borescope check
- Certified fill to the separating wall
- Sealing at the top of the cavity
- Neighbour notification guidance
- Written result and photos
Party wall cavity insulation prices in County Londonderry
| Party wall cavity insulation guide prices | Guide price |
|---|---|
| Party wall, two-storey house | £595–£895 |
| Party wall, bungalow | £395–£695 |
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.
What happens next for a County Londonderry property:
Get in touch
Online, by phone or WhatsApp, whichever suits you.
Survey visit
The surveyor checks each wall and looks into the cavity where needed.
Your result in writing
What we found, what it means, and a fixed price if work is needed.
Booked work
Carried out by the installer named on your quote, with their scheme registrations.