Mineral wool EWI · Wales
Mineral wool external wall insulation in Powys
We provide mineral wool external wall insulation across Powys, including Newtown, Brecon and Welshpool, with a free survey and fixed written price. On blocks and taller buildings in Powys, mineral wool is the default because of the fire guidance for external walls.
- Free survey and fixed written price
- Guide price from £125 per m² + scaffold, 0% VAT
- Planning and building control checked for Wales
Free survey in Powys
Tell us the postcode and what you need.
What the job covers
- Better sound reduction than foam boards
- Finished in mineral or silicone render, or brick slip
- Used on blocks of flats and buildings with storeys above 11m
- Non-combustible board (typically Euroclass A1 or A2-s1,d0 as part of the system)
- Heavier than EPS, so more fixings and careful handling
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.
For homes in Powys near busy roads, mineral wool's sound reduction can be a reason to choose it.
- Nation
- Wales
- Region
- Mid Wales
- Towns covered
- Newtown, Brecon, Welshpool, Llandrindod Wells
- Guide price
- From £125 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.
Wales applies its own amended fire rules for external walls, including the combustible materials ban for relevant buildings and guidance for residential buildings between 11 and 18 metres, updated by the Building (Amendment) (Wales) Regulations 2025.
Why choose mineral wool over EPS?
Two reasons come up most: fire and moisture. Mineral wool doesn't burn, which is why guidance for taller residential buildings points to non-combustible external wall materials. It is also vapour-open, so a solid wall that holds some moisture can keep drying outwards through the insulation and render.
The trade-offs are weight and cost. Slabs are denser, need more fixings and take longer to install, so the price per m² is higher than EPS.
Mineral wool external wall insulation prices in Powys
| Item | Guide price | Notes |
|---|---|---|
| Mineral wool + mineral or silicone render | £125–£170 per m²0% VAT | Excluding scaffold |
| Mineral wool + brick slip | £195–£260 per m²0% VAT | Heavier slip systems need extra fixings |
| Three-bed semi, full house | £11,800–£20,2000% VAT | 80–100 m² of wall, including scaffold |
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
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.
Mineral wool EWI in Powys: questions
Is mineral wool better than EPS?
Not always better — different. Mineral wool wins on fire performance, breathability and acoustics; EPS wins on cost, weight and thinner boards for the same U-value. The wall, the building height and your priorities decide it.
Does mineral wool get wet?
It is water-repellent and protected by the render system. Like any insulation it must not be left exposed to rain during installation, so boards are covered and work stops in wet weather.
Is mineral wool needed for a bungalow?
Rarely for fire reasons. It may still be chosen on a damp-prone solid wall where a vapour-open build-up is wanted.
Do you cover all of Powys?
Yes. We survey and quote mineral wool external 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.