Non-traditional houses · Wales
Non-traditional and concrete house insulation in Gwynedd
We provide non-traditional house insulation across Gwynedd, including Bangor (Gwynedd), Holyhead and Caernarfon, with a free survey and fixed written price. For concrete houses in Gwynedd, we report any visible spalling or cracking before quoting the insulation, not after.
- Free survey and fixed written price
- Guide price from £120 per m² + scaffold, 0% VAT
- Planning and building control checked for Wales
Free survey in Gwynedd
Tell us the postcode and what you need.
What's included
- Steel-framed BISF houses need care around the upper-storey cladding
- EWI improves comfort and can renew a tired concrete exterior
- Fixing design depends on the panel or frame behind the wall
- The survey identifies the construction type before anything is specified
- EWI is not a structural repair for PRC houses designated defective

What we look for in 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 concrete houses in Gwynedd, we report any visible spalling or cracking before quoting the insulation, not after.
- Nation
- Wales
- Region
- North Wales
- Towns covered
- Bangor (Gwynedd), Holyhead, Caernarfon, Llangefni
- Guide price
- From £120 per m² + scaffold · 0% VAT
Permissions in Wales
Permitted development rules for houses in Wales are similar to England's: a similar-appearance finish on a house is often permitted, while conservation areas, National Parks, Areas of Outstanding Natural Beauty, flats, commercial buildings and listed buildings need permission or consent. Your local planning authority has the final word.
The Building Regulations as they apply in Wales treat insulating or re-rendering more than half of a wall's area, or more than a quarter of the building's whole envelope, as renovating a thermal element, with Approved Document L (Wales) setting the target. Building control is involved before work starts.
Does EWI fix mortgage problems with PRC houses?
Not on its own. Some precast reinforced concrete (PRC) house types were designated defective, and many lenders want a certified structural repair before they will lend. Insulation and render over the outside is not that repair. Other types, such as Wimpey no-fines, are generally treated differently. If mortgageability matters, speak to your lender or a surveyor before booking any work.
Non-traditional and concrete house insulation prices in Gwynedd
| Item | Guide price | Notes |
|---|---|---|
| EWI on concrete or steel-framed walls | £120–£180 per m²0% VAT | Includes extra preparation |
| Semi-detached, full house | £11,400–£21,2000% VAT | 80–100 m² of wall, including scaffold |
| Concrete repairs found at survey | Priced separately | Only where needed |
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
Enquiry
Send your postcode and a few details.
Measured survey
Walls, damp, eaves, cills and services recorded.
Written price
A fixed price with the specification attached.
Work and handover
Installed, inspected and documents handed over.
Non-traditional houses in Gwynedd: questions
Can you put EWI on a BISF house?
Yes, with care. The steel frame and upper-storey cladding need a system and fixing method designed for that construction, and the condition of the frame should be understood first.
Can you insulate a Wimpey no-fines house?
Yes. No-fines houses have solid poured-concrete walls with no cavity, so EWI is the usual route. The survey checks the concrete condition first.
Will EWI make my house mortgageable?
It can make a house more attractive and better insulated, but it does not replace a certified structural repair where a lender requires one. Ask your lender before relying on it.
Do you cover all of Gwynedd?
Yes. We survey and quote non-traditional house insulation across Gwynedd, including Bangor (Gwynedd), Holyhead, Caernarfon, Llangefni.
Do I need planning permission in Wales?
Permitted development rules for houses in Wales are similar to England's: a similar-appearance finish on a house is often permitted, while conservation areas, National Parks, Areas of Outstanding Natural Beauty, flats, commercial buildings and listed buildings need permission or consent. We check your address before quoting.