Mineral wool EWI · Wales
Mineral wool external wall insulation in Mid Glamorgan
Mineral wool external wall insulation across Mid Glamorgan: measured survey, clear specification and a fixed written price before any work starts. On blocks and taller buildings in Mid Glamorgan, 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 Mid Glamorgan
Tell us the postcode and what you need.
Included as standard
- Heavier than EPS, so more fixings and careful handling
- Finished in mineral or silicone render, or brick slip
- Vapour-open, so moisture in solid walls can dry outwards
- Better sound reduction than foam boards
- Non-combustible board (typically Euroclass A1 or A2-s1,d0 as part of the system)

Mid Glamorgan: walls, weather and approvals
South Wales has long runs of solid-wall valley terraces, Victorian and Edwardian town housing and post-war council estates.
Parts of Mid Glamorgan 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.
Older solid-walled homes in Mid Glamorgan can suit a vapour-open mineral wool build-up better than foam; the survey checks the wall first.
- Nation
- Wales
- Region
- South Wales
- Towns covered
- Rhondda, Bridgend, Merthyr Tydfil, Aberdare, Pontypridd, Maesteg
- Guide price
- From £125 per m² + scaffold · 0% VAT
Planning and building control 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.
What about noise?
Dense mineral wool adds mass and absorbs sound, so homes beside main roads or railways often notice a quieter interior, particularly where windows are also upgraded. The improvement depends on the whole wall and windows, so we don't quote decibel figures without testing.
Mineral wool external wall insulation prices in Mid Glamorgan
| 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.
What happens next
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.
Mineral wool EWI in Mid Glamorgan: questions
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.
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.
Do you cover all of Mid Glamorgan?
Yes. We survey and quote mineral wool external wall insulation across Mid Glamorgan, including Rhondda, Bridgend, Merthyr Tydfil, Aberdare, Pontypridd.
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.