Solid wall insulation · Gwynedd
Solid wall insulation in Caernarfon
Solid wall insulation in Caernarfon: free survey, written specification and a fixed price, with the details that keep walls dry planned from the start. On solid-walled houses in Caernarfon, the gable or the most weather-exposed wall is often the place to start.
- Free survey in LL55 and nearby
- Guide price from £75 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Caernarfon
Postcode, service and a phone number is all we need.
What you get
- Solid walls can lose heat roughly twice as fast as an insulated cavity wall
- In England and Wales, Building Regulations apply when more than half of a wall is treated
- Internal insulation suits single rooms or where the outside can't change
- External insulation keeps room sizes and treats cold bridges well
What we look for in Caernarfon
Surveys in Caernarfon also cover the surrounding LL55 district and towns such as Llangefni and Bangor (Gwynedd). Caernarfon sits around 8 miles from Bangor (Gwynedd). North Wales has many solid stone and slate-built homes, Victorian seaside terraces and post-war council estates.
Parts of Gwynedd 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 Caernarfon homeowners weighing external against internal insulation, the survey sets out both with prices.
- Postcode district
- LL55
- County or area
- Gwynedd
- Nation
- Wales
- Nearby
- Llangefni, Bangor (Gwynedd), Holyhead, Llandudno
Wales: planning and regulations
Householder rules in Wales are similar to England's: in Caernarfon, a similar-looking finish on a house is often permitted, but conservation areas, flats and listed buildings need permission or consent.
Building control in Wales applies to most insulation and re-rendering jobs of this size; the quote states who submits the notice.
External or internal — which is better?
External insulation keeps the wall warm, reduces cold bridging at floors and party walls, renews the outside, and doesn't shrink rooms — but it changes the look and needs scaffolding. Internal insulation keeps the façade unchanged and can be done room by room, but loses 50–100mm of floor space per wall and needs careful detailing to avoid condensation at joists and corners.
Solid wall insulation prices in Caernarfon
| 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.
From enquiry to finished wall
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 Caernarfon: 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 get a grant for solid wall insulation?
Some schemes cover it for eligible households — for example ECO4 until 31 December 2026, Home Energy Scotland's grant and loan, Wales' Warm Homes Nest and NI's Affordable Warmth Scheme. Each has its own eligibility and installer rules; see our grants guide.
Can I do one wall at a time?
Yes. Many owners start with the coldest or most exposed elevation, often a gable end.
Do you cover Caernarfon?
Yes — we survey and quote solid wall insulation in Caernarfon (LL55) and nearby Llangefni, Bangor (Gwynedd) and Holyhead, with a fixed written price before any work starts.