External wall insulation · Cornwall
External wall insulation in St Austell
External wall insulation in St Austell: free survey, written specification and a fixed price, with the details that keep walls dry planned from the start. For homes in St Austell, the survey starts with the wall itself: solid brick, stone or concrete, and whether any old render is sound enough to insulate over.
- Free survey in PL25 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in St Austell
Postcode, service and a phone number is all we need.
Included as standard
- Installing wall insulation in homes is currently zero-rated for VAT until 31 March 2027
- 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
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic

Homes and walls in St Austell
Surveys in St Austell also cover the surrounding PL25 district and towns such as Bodmin and Truro. St Austell is about 21 miles from Redruth. The South West has many stone and solid-walled cottages, exposed coastal properties and a share of post-war system-built houses, including types such as the Cornish Unit.
Parts of Cornwall 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 St Austell around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Postcode district
- PL25
- County or area
- Cornwall
- Nation
- England
- Nearby
- Bodmin, Truro, Newquay, Falmouth
England: planning and regulations
Before quoting in St Austell, we check whether the property is in a conservation area, under an Article 4 direction or listed, because that decides whether changing the outside needs planning permission.
Building control applies once more than half of a wall is insulated or re-rendered, or more than a quarter of the whole building envelope, and your written quote says how that's handled.
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 St Austell
| 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.
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.
External wall insulation in St Austell: questions
Do I need planning permission for external wall insulation?
Often not for a house in England or Wales if the finish looks similar to the existing walls. You will usually need permission in a conservation area, on flats, on commercial buildings or where the appearance changes noticeably. Listed buildings need listed building consent. We check your address before quoting.
Does external wall insulation cause damp?
Not when it is specified and detailed properly. Problems usually come from poor detailing: no starter track above the damp-proof course, gaps at cills and penetrations, or a vapour-closed system on a wall that needs to breathe. The survey checks moisture, ground levels and the wall type before a system is chosen.
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 St Austell?
Yes — we survey and quote external wall insulation in St Austell (PL25) and nearby Bodmin, Truro and Newquay, with a fixed written price before any work starts.