EPS insulation · Wales
EPS external wall insulation in Gwynedd
Get guide prices online, then a free survey and fixed quote for EPS external wall insulation in Gwynedd, including Holyhead and Caernarfon. We compare EPS against mineral wool for each Gwynedd enquiry rather than assuming one board suits every wall.
- Free survey and fixed written price
- Guide price from £105 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
- Thermal conductivity around 0.031–0.038 W/mK depending on grade
- Grey graphite EPS reaches a given U-value with a thinner board
- Used on low-rise houses; combustible, so not for taller buildings
- Light boards mean fewer fixings and a faster install
- Easy to shape around bays, arches and reveals

Before we quote 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.
We compare EPS against mineral wool for each Gwynedd enquiry rather than assuming one board suits every wall.
- Nation
- Wales
- Region
- North Wales
- Towns covered
- Bangor (Gwynedd), Holyhead, Caernarfon, Llangefni
- Guide price
- From £105 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.
How thick does the board need to be?
On a 225mm solid brick wall, around 90mm of grey EPS or 100–110mm of white EPS typically gets close to 0.30 W/m²K. Stone walls, concrete panels and hollow-block walls start from different points, so the system supplier's calculation for your wall sets the final thickness.
EPS external wall insulation prices in Gwynedd
| Item | Guide price | Notes |
|---|---|---|
| EPS + silicone render | £105–£145 per m²0% VAT | Excluding scaffold |
| Grey EPS uplift | +£4–£8 per m²0% VAT | Thinner board for the same U-value |
| Bungalow, full house | £6,700–£12,8000% VAT | 55–75 m² of wall, including scaffold |
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.
EPS insulation in Gwynedd: questions
Is EPS insulation safe on a house?
EPS is used inside render systems that are fire-tested as a whole. On low-rise houses it is widely used. On taller buildings, or where guidance calls for non-combustible materials, mineral wool systems are specified instead.
Will woodpeckers damage EPS?
It happens occasionally, especially near woodland. Damage is to the render and board surface and is repaired with a mesh patch and colour-matched finish.
White or grey EPS?
Grey graphite EPS insulates better per millimetre, so it is the pick where space is tight at the eaves or around windows. White EPS is slightly cheaper and works well where the extra thickness isn't a problem.
Do you cover all of Gwynedd?
Yes. We survey and quote EPS 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.