Solid wall insulation · Northern Ireland
Solid wall insulation in County Londonderry
Quotes for solid wall insulation in County Londonderry set out the system, detailing, access and VAT position in writing. For County Londonderry homeowners weighing external against internal insulation, the survey sets out both with prices.
- Free survey and fixed written price
- Guide price from £75 per m² + scaffold, 0% VAT
- Planning and building control checked for Northern Ireland
Free survey in County Londonderry
Tell us the postcode and what you need.
Part of every quote
- Solid walls can lose heat roughly twice as fast as an insulated cavity wall
- External insulation keeps room sizes and treats cold bridges well
- Both can be done in stages, elevation by elevation or room by room
- Internal insulation suits single rooms or where the outside can't change
- Breathable options for stone and lime-mortared walls

What we look for in County Londonderry
Northern Ireland has many rendered and pebble-dashed homes, older solid-walled rural houses, and estates built by the Housing Executive.
Parts of County Londonderry fall in the higher wind-driven rain exposure bands, especially coastal and upland sites, so render specification, movement joints and detailing at cills, verges and the base of the wall matter more than usual.
For solid-walled homes in County Londonderry, we check wall thickness and age first to confirm there's no cavity to fill.
- Nation
- Northern Ireland
- Region
- Northern Ireland
- Towns covered
- Derry~Londonderry, Coleraine, Limavady, Magherafelt
- Guide price
- From £75 per m² + scaffold · 0% VAT
Northern Ireland: planning and regulations
In Northern Ireland, permitted development is set by the Planning (General Permitted Development) Order (NI) 2015. Changing the external appearance of a house may need permission, and conservation areas, flats, commercial buildings and listed buildings need planning permission or listed building consent. Check with your council's planning office.
Insulating external walls is building work under the Building Regulations (Northern Ireland) 2012, handled by council building control, with Technical Booklet F1 covering conservation of fuel and power in dwellings.
What does solid wall insulation cost?
External systems run at roughly £105–£210 per m² of wall depending on the board and finish. Internal insulation is roughly £75–£130 per m², plus the cost of moving radiators, sockets and kitchen units.
Solid wall insulation prices in County Londonderry
| Item | Guide price | Notes |
|---|---|---|
| External (EWI) | £105–£210 per m²0% VAT | By board and finish |
| Internal (IWI) | £75–£130 per m²0% VAT | Plus making good |
| Survey and written recommendation | Free with a quote |
Confirmed by a fixed written quote after survey. 0% VAT: installing insulation in a home is zero-rated until 31 March 2027, so these figures are the total; 5% applies from 1 April 2027.
What happens next
Get a guide price
Try the online quote tool for a ballpark figure.
Book the survey
A visit at a time that suits you.
Agree the quote
Nothing starts until you've signed the written price.
We do the work
Planned around weather, with you kept informed.
Solid wall insulation in County Londonderry: questions
Is solid wall insulation worth it?
For many solid-walled homes it's one of the biggest single improvements to comfort, because the walls are often the largest heat-loss area. Savings depend on the home and heating, so we don't promise a figure.
Can I do one wall at a time?
Yes. Many owners start with the coldest or most exposed elevation, often a gable end.
Does solid wall insulation cause condensation?
It can if detailed poorly, particularly internally. A condensation risk check for the proposed build-up and careful detailing at joists, reveals and corners avoid it.
Do you cover all of County Londonderry?
Yes. We survey and quote solid wall insulation across County Londonderry, including Derry~Londonderry, Coleraine, Limavady, Magherafelt.
Do I need planning permission in Northern Ireland?
In Northern Ireland, permitted development is set by the Planning (General Permitted Development) Order (NI) 2015. We check your address before quoting.