External wall insulation · Gwynedd
External wall insulation in Holyhead
Looking for external wall insulation in Holyhead? We survey homes across Holyhead and the LL65 area, then give you a fixed written price before any work starts. We plan EWI in Holyhead around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Free survey in LL65 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Holyhead
Postcode, service and a phone number is all we need.
Included as standard
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board
- Cills, pipes, vents, meter boxes and the roofline detailed as part of the job
- Covers tired brick, pebble dash or failing render with a new finish
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic

Before we quote in Holyhead
Surveys in Holyhead also cover the surrounding LL65 district and towns such as Llangefni and Caernarfon. It's roughly 22 miles from Holyhead to Bangor (Gwynedd), the largest town 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 homes in Holyhead, the survey starts with the wall itself: solid brick, stone or concrete, and whether any old render is sound enough to insulate over.
- Postcode district
- LL65
- County or area
- Gwynedd
- Nation
- Wales
- Nearby
- Llangefni, Caernarfon, Bangor (Gwynedd), Llandudno
Wales: planning and regulations
We check Holyhead addresses for conservation areas and listing before quoting, because Welsh permitted development rules don't cover every external change.
In Wales, insulating or re-rendering more than half of a wall's area is treated as renovating a thermal element under Approved Document L (Wales), so building control is involved before work starts.
How does external wall insulation work?
Heat moves out through a wall faster when the wall is solid or poorly insulated. EWI wraps the outside face in a continuous layer of insulation, so the masonry stays on the warm side and the cold bridges at floor and party-wall junctions are reduced. The boards are bonded with adhesive and, on most walls, mechanically fixed. A base coat with an embedded glass-fibre mesh goes over the top, then a primer and the decorative finish.
Because the wall itself sits inside the insulation, it stays warmer and drier, and the rooms keep their full size. That is the main difference from internal insulation.
External wall insulation prices in Holyhead
| Item | Guide price | Notes |
|---|---|---|
| EPS system with silicone render | £105–£145 per m²0% VAT | Most common choice for houses |
| Mineral wool system | £125–£170 per m²0% VAT | Non-combustible, vapour-open |
| Brick-slip finish over insulation | £185–£260 per m²0% VAT | Where a brick look is wanted |
| Three-bed semi, EPS + silicone (incl. scaffold) | £10,200–£17,7000% VAT | 80–100 m² of wall; depends on detailing and access |
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.
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.
External wall insulation in Holyhead: questions
Does EWI need Building Regulations approval?
In England and Wales, usually. Insulating more than half of a wall's area, or more than a quarter of the building's whole external envelope, counts as renovating a thermal element, so building control needs to be involved and the wall should reach about 0.30 W/m²K where that's practical. Scotland and Northern Ireland have their own building standards processes.
How much does external wall insulation cost?
Our guide price for EWI is £105–£170 per m² of wall depending on the system, plus scaffolding. A typical three-bed semi with EPS and silicone render comes to roughly £10,200–£17,700 for the whole house, including scaffold. Installing insulation in a home is zero-rated for VAT until 31 March 2027, so that's the total. You get a fixed written price after a free survey.
How long does external wall insulation last?
A well-installed render system is commonly expected to last 25–30 years or more, with occasional cleaning and inspection of sealants. The system manufacturer's documentation states the expected service life for the specific build-up.
Do you cover Holyhead?
Yes — we survey and quote external wall insulation in Holyhead (LL65) and nearby Llangefni, Caernarfon and Bangor (Gwynedd), with a fixed written price before any work starts.