Mineral wool EWI · Hampshire
Mineral wool external wall insulation in Portsmouth
Looking for mineral wool external wall insulation in Portsmouth? We survey homes across Portsmouth and the PO5 area, then give you a fixed written price before any work starts. Older solid-walled homes in Portsmouth can suit a vapour-open mineral wool build-up better than foam; the survey checks the wall first.
- Free survey in PO5 and nearby
- Guide price from £125 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Portsmouth
Postcode, service and a phone number is all we need.
Part of every quote
- Used on blocks of flats and buildings with storeys above 11m
- Better sound reduction than foam boards
- Heavier than EPS, so more fixings and careful handling
- Vapour-open, so moisture in solid walls can dry outwards
What we look for in Portsmouth
We also cover Gosport and Fareham, close to Portsmouth. Portsmouth sits around 15 miles from Southampton. 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 Hampshire: 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 Portsmouth near busy roads, mineral wool's sound reduction can be a reason to choose it.
- Postcode district
- PO5
- County or area
- Hampshire
- Nation
- England
- Nearby
- Gosport, Fareham, Ryde, Havant
Planning and building control in England
For a house in Portsmouth, 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.
If the work covers more than half of a wall, or a quarter of the building's whole envelope, it counts as renovating a thermal element, with a target of about 0.30 W/m²K where feasible.
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 Portsmouth
| 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
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 Portsmouth: questions
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.
Can mineral wool EWI have a brick finish?
Yes. Brick slips can be bonded over mineral wool systems designed for them, with additional fixings for the extra weight.
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 Portsmouth?
Yes — we survey and quote mineral wool external wall insulation in Portsmouth (PO5) and nearby Gosport, Fareham and Ryde, with a fixed written price before any work starts.