Wood fibre EWI · Wales
Wood fibre insulation for older homes in Gwynedd
Homes and buildings across Gwynedd — from Bangor (Gwynedd) to Caernarfon — can get a free survey and written quote for wood fibre external wall insulation. If your home in Gwynedd is in a conservation area, we check the council's position on render before suggesting wood fibre EWI.
- Free survey and fixed written price
- Guide price from £150 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 you get
- Made from a renewable material with low embodied carbon
- Compatible with lime renders used on traditional buildings
- Thicker than foam for the same U-value
- Vapour-open and hygroscopic — buffers moisture rather than trapping it
- Often the most suitable EWI where planning allows on older properties

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 period homes in Gwynedd, the survey looks closely at existing lime mortars and any cement patching that may trap moisture.
- Nation
- Wales
- Region
- North Wales
- Towns covered
- Bangor (Gwynedd), Holyhead, Caernarfon, Llangefni
- Guide price
- From £150 per m² + scaffold · 0% VAT
Wales: planning and regulations
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.
What about listed buildings and conservation areas?
EWI on a listed building needs listed building consent and is often refused where the outside appearance matters. In conservation areas, rendering or cladding a house normally needs planning permission. Wood fibre and lime are more likely to be acceptable than foam and acrylic, but the council decides. We check before quoting.
Wood fibre insulation for older homes prices in Gwynedd
| Item | Guide price | Notes |
|---|---|---|
| Wood fibre + lime render system | £150–£210 per m²0% VAT | Excluding scaffold |
| Cottage, about 90 m² of wall | £15,300–£22,1000% VAT | Including scaffold |
| Lime render only (no insulation) | £78–£132 per m²inc VAT | See lime render |
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. Prices include VAT at 20%.
How it works
Tell us about the property
Use the quote tool or form, or call. Photos help.
Free survey
We measure, check the walls and confirm approvals.
Fixed written quote
System, details, access, exclusions and VAT in writing.
Installation
Scheduled for suitable weather, with a clear programme.
Wood fibre EWI in Gwynedd: questions
Does wood fibre need a lime render?
It needs the render specified by the system manufacturer, which is usually lime or mineral based.
Can wood fibre go on a stone wall?
Yes, after levelling. Rubble stone is often uneven, so a levelling coat or adapted fixing method is used first.
Is wood fibre worth the extra cost?
On older solid walls the main benefit is moisture safety rather than raw U-value. If the wall needs to breathe, the cheaper option can cost more later.
Do you cover all of Gwynedd?
Yes. We survey and quote wood fibre external wall 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.