External wall insulation · Wiltshire
External wall insulation in Chippenham
From Chippenham to Trowbridge, we price external wall insulation after a measured survey — no guesswork, and no work starts until the price is agreed in writing. We plan EWI in Chippenham around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Free survey in SN15 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Chippenham
Postcode, service and a phone number is all we need.
What the job covers
- Installing wall insulation in homes is currently zero-rated for VAT until 31 March 2027
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board
- Covers tired brick, pebble dash or failing render with a new finish
Homes and walls in Chippenham
As well as Chippenham itself, we quote in Trowbridge, Bath and Chipping Sodbury. It's roughly 16 miles from Chippenham to Swindon, the largest town in Wiltshire. 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.
Exposure to wind-driven rain varies across Wiltshire: sheltered town streets fare better than walls on high ground or facing the prevailing weather, and the render, beads and cill details are chosen with that in mind.
Whole-house jobs and single elevations are both quoted in Chippenham; a cold gable or rear wall can be done on its own where it suits.
- Postcode district
- SN15
- County or area
- Wiltshire
- Nation
- England
- Nearby
- Trowbridge, Bath, Chipping Sodbury, Yate
Planning and building control in England
Before quoting in Chippenham, 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.
Insulating or re-rendering more than half of a wall's area brings in Part L of the Building Regulations, so building control is notified and the wall is upgraded to about 0.30 W/m²K where practical.
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 Chippenham
| 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
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 Chippenham: questions
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.
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.
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.
Do you cover Chippenham?
Yes — we survey and quote external wall insulation in Chippenham (SN15) and nearby Trowbridge, Bath and Chipping Sodbury, with a fixed written price before any work starts.