Mineral wool EWI · West Sussex
Mineral wool external wall insulation in Horsham
Homeowners and landlords in Horsham can get a free survey and a fixed written quote for mineral wool external wall insulation, covering RH12 and the surrounding area. Older solid-walled homes in Horsham can suit a vapour-open mineral wool build-up better than foam; the survey checks the wall first.
- Free survey in RH12 and nearby
- Guide price from £125 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Horsham
Postcode, service and a phone number is all we need.
Included as standard
- Non-combustible board (typically Euroclass A1 or A2-s1,d0 as part of the system)
- Vapour-open, so moisture in solid walls can dry outwards
- Finished in mineral or silicone render, or brick slip
- Used on blocks of flats and buildings with storeys above 11m
Local considerations in Horsham
Surveys in Horsham also cover the surrounding RH12 district and towns such as Crawley and Horley. Horsham sits around 7 miles from Crawley. Homes across the South East range from inter-war semis and post-war estates, which are mostly cavity-walled, to older solid-walled cottages and Victorian town terraces.
Exposure to wind-driven rain varies across West Sussex: 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.
For homes in Horsham near busy roads, mineral wool's sound reduction can be a reason to choose it.
- Postcode district
- RH12
- County or area
- West Sussex
- Nation
- England
- Nearby
- Crawley, Horley, Haywards Heath, Burgess Hill
Approvals in England
For a house in Horsham, external insulation or render is often permitted development if it looks similar to the existing walls; conservation areas, flats, commercial buildings and listed buildings need permission or consent, so we check your address first.
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.
On residential buildings with a storey 11 metres or more above ground, guidance points to non-combustible external wall materials, and combustible materials are banned in relevant buildings 18 metres and over, so we specify mineral wool systems there.
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 Horsham
| 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
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.
Mineral wool EWI in Horsham: 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 Horsham?
Yes — we survey and quote mineral wool external wall insulation in Horsham (RH12) and nearby Crawley, Horley and Haywards Heath, with a fixed written price before any work starts.