Solid wall insulation · England
Solid wall insulation in Wiltshire
Solid wall insulation across Wiltshire: measured survey, clear specification and a fixed written price before any work starts. For solid-walled homes in Wiltshire, we check wall thickness and age first to confirm there's no cavity to fill.
- Free survey and fixed written price
- Guide price from £75 per m² + scaffold, 0% VAT
- Planning and building control checked for England
Free survey in Wiltshire
Tell us the postcode and what you need.
Part of every quote
- Both can be done in stages, elevation by elevation or room by room
- Breathable options for stone and lime-mortared walls
- Internal insulation suits single rooms or where the outside can't change
- In England and Wales, Building Regulations apply when more than half of a wall is treated
- External insulation keeps room sizes and treats cold bridges well

Before we quote 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.
On solid-walled houses in Wiltshire, the gable or the most weather-exposed wall is often the place to start.
- Nation
- England
- Region
- South West
- Towns covered
- Swindon, Salisbury, Trowbridge, Chippenham
- Guide price
- From £75 per m² + scaffold · 0% VAT
England: planning and regulations
For houses, external wall insulation and render are often permitted development where the finish looks similar to the existing walls. Planning permission is usually needed in conservation areas, National Parks, National Landscapes, the Broads and World Heritage Sites (where cladding a house in stone, artificial stone, pebble dash, render, timber, plastic or tiles isn't permitted development), for flats and maisonettes, for commercial buildings, under an Article 4 direction, or where the look changes noticeably. Listed buildings need listed building consent.
Renovating more than half of a wall's area — insulating it, or stripping and re-rendering it — or more than a quarter of the building's whole external envelope brings in the energy requirements of Part L, so building control needs to be involved and the wall should reach about 0.30 W/m²K where that's technically, functionally and economically feasible.
What does solid wall insulation cost?
External systems run at roughly £105–£210 per m² of wall depending on the board and finish. Internal insulation is roughly £75–£130 per m², plus the cost of moving radiators, sockets and kitchen units.
Solid wall insulation prices in Wiltshire
| Item | Guide price | Notes |
|---|---|---|
| External (EWI) | £105–£210 per m²0% VAT | By board and finish |
| Internal (IWI) | £75–£130 per m²0% VAT | Plus making good |
| Survey and written recommendation | Free with a quote |
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.
Solid wall insulation in Wiltshire: questions
Does solid wall insulation cause condensation?
It can if detailed poorly, particularly internally. A condensation risk check for the proposed build-up and careful detailing at joists, reveals and corners avoid it.
Can I get a grant for solid wall insulation?
Some schemes cover it for eligible households — for example ECO4 until 31 December 2026, Home Energy Scotland's grant and loan, Wales' Warm Homes Nest and NI's Affordable Warmth Scheme. Each has its own eligibility and installer rules; see our grants guide.
Can I do one wall at a time?
Yes. Many owners start with the coldest or most exposed elevation, often a gable end.
Do you cover all of Wiltshire?
Yes. We survey and quote solid wall insulation across Wiltshire, including Swindon, Salisbury, Trowbridge, Chippenham.
Do I need planning permission in England?
For houses, external wall insulation and render are often permitted development where the finish looks similar to the existing walls. We check your address before quoting.