Solid wall insulation · Wales
Solid wall insulation in Powys
Solid wall insulation across Powys: measured survey, clear specification and a fixed written price before any work starts. For solid-walled homes in Powys, 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 Wales
Free survey in Powys
Tell us the postcode and what you need.
Part of every quote
- In England and Wales, Building Regulations apply when more than half of a wall is treated
- Breathable options for stone and lime-mortared walls
- Internal insulation suits single rooms or where the outside can't change
- Both can be done in stages, elevation by elevation or room by room
- Solid walls can lose heat roughly twice as fast as an insulated cavity wall

What we look for in Powys
Mid Wales is largely rural, with stone farmhouses, cottages and market-town terraces, many of them solid-walled.
Parts of Powys 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.
On solid-walled houses in Powys, the gable or the most weather-exposed wall is often the place to start.
- Nation
- Wales
- Region
- Mid Wales
- Towns covered
- Newtown, Brecon, Welshpool, Llandrindod Wells
- Guide price
- From £75 per m² + scaffold · 0% VAT
Permissions in Wales
Permitted development rules for houses in Wales are similar to England's: a similar-appearance finish on a house is often permitted, while conservation areas, National Parks, Areas of Outstanding Natural Beauty, flats, commercial buildings and listed buildings need permission or consent. Your local planning authority has the final word.
The Building Regulations as they apply in Wales treat insulating or re-rendering more than half of a wall's area, or more than a quarter of the building's whole envelope, as renovating a thermal element, with Approved Document L (Wales) setting the target. Building control is involved before work starts.
External or internal — which is better?
External insulation keeps the wall warm, reduces cold bridging at floors and party walls, renews the outside, and doesn't shrink rooms — but it changes the look and needs scaffolding. Internal insulation keeps the façade unchanged and can be done room by room, but loses 50–100mm of floor space per wall and needs careful detailing to avoid condensation at joists and corners.
Solid wall insulation prices in Powys
| 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.
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.
Solid wall insulation in Powys: 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.
Is solid wall insulation worth it?
For many solid-walled homes it's one of the biggest single improvements to comfort, because the walls are often the largest heat-loss area. Savings depend on the home and heating, so we don't promise a figure.
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 Powys?
Yes. We survey and quote solid wall insulation across Powys, including Newtown, Brecon, Welshpool, Llandrindod Wells.
Do I need planning permission in Wales?
Permitted development rules for houses in Wales are similar to England's: a similar-appearance finish on a house is often permitted, while conservation areas, National Parks, Areas of Outstanding Natural Beauty, flats, commercial buildings and listed buildings need permission or consent. We check your address before quoting.