External wall insulation · Dyfed
External wall insulation in Carmarthen
From Carmarthen to Llanelli, we price external wall insulation after a measured survey — no guesswork, and no work starts until the price is agreed in writing. Whole-house jobs and single elevations are both quoted in Carmarthen; a cold gable or rear wall can be done on its own where it suits.
- Free survey in SA31 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Carmarthen
Postcode, service and a phone number is all we need.
What the job covers
- Work happens outside, so you can live at home throughout
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic
- Cills, pipes, vents, meter boxes and the roofline detailed as part of the job
- Installing wall insulation in homes is currently zero-rated for VAT until 31 March 2027

Homes and walls in Carmarthen
We also cover Llanelli and Ammanford, close to Carmarthen. Carmarthen sits around 14 miles from Llanelli. West Wales has a high share of older solid-walled and stone homes, many in exposed coastal or rural settings.
Parts of Dyfed 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 plan EWI in Carmarthen around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Postcode district
- SA31
- County or area
- Dyfed
- Nation
- Wales
- Nearby
- Llanelli, Ammanford, Gorseinon, Swansea
Approvals in Wales
For homes in Carmarthen, the local planning authority decides any borderline cases; changing a brick house to render, or work on flats, usually needs an application in Wales.
Building control in Wales applies to most insulation and re-rendering jobs of this size; the quote states who submits the notice.
What finish can I have?
Most EWI is finished in a thin-coat silicone render in a through-coloured shade, with a 1–2mm grain. Acrylic, mineral (painted), dry-dash and brick-slip finishes are also available. Where planning wants a brick look, brick slips over the insulation keep the street appearance.
External wall insulation prices in Carmarthen
| 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.
What happens next
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.
External wall insulation in Carmarthen: questions
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.
Can EWI go over pebble dash?
Usually yes. The dash is tested for adhesion and hollow areas; sound dash can be insulated over with additional mechanical fixings, while loose areas are removed first.
Do you cover Carmarthen?
Yes — we survey and quote external wall insulation in Carmarthen (SA31) and nearby Llanelli, Ammanford and Gorseinon, with a fixed written price before any work starts.