External wall insulation · Greater London
External wall insulation in Streatham
Looking for external wall insulation in Streatham? We survey homes across Streatham and the SW16 area, then give you a fixed written price before any work starts. We plan EWI in Streatham around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Free survey in SW16 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Streatham
Postcode, service and a phone number is all we need.
Included as standard
- Installing wall insulation in homes is currently zero-rated for VAT until 31 March 2027
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board
- Work happens outside, so you can live at home throughout
- Cills, pipes, vents, meter boxes and the roofline detailed as part of the job
Homes and walls in Streatham
As well as Streatham itself, we quote in Mitcham, Brixton and Wimbledon. London's housing includes a large stock of Victorian and Edwardian solid-wall terraces, inter-war semis and post-war blocks, and conservation areas cover many streets — so planning is often the first question for external work.
Much of Greater London sits in the lower wind-driven rain exposure bands, which keeps the choice of finishes wide — though hilltop, coastal and exposed gable walls can still need a tougher specification, so we check the actual site.
For homes in Streatham, the survey starts with the wall itself: solid brick, stone or concrete, and whether any old render is sound enough to insulate over.
- Postcode district
- SW16
- County or area
- Greater London
- Nation
- England
- Nearby
- Mitcham, Brixton, Wimbledon, Battersea
Approvals in England
Before quoting in Streatham, we check whether the property is in a conservation area, under an Article 4 direction or listed, because that decides whether changing the outside needs planning permission.
Building control applies once more than half of a wall is insulated or re-rendered, or more than a quarter of the whole building envelope, and your written quote says how that's handled.
How does external wall insulation work?
Heat moves out through a wall faster when the wall is solid or poorly insulated. EWI wraps the outside face in a continuous layer of insulation, so the masonry stays on the warm side and the cold bridges at floor and party-wall junctions are reduced. The boards are bonded with adhesive and, on most walls, mechanically fixed. A base coat with an embedded glass-fibre mesh goes over the top, then a primer and the decorative finish.
Because the wall itself sits inside the insulation, it stays warmer and drier, and the rooms keep their full size. That is the main difference from internal insulation.
External wall insulation prices in Streatham
| Item | Guide price | Notes |
|---|---|---|
| EPS system with silicone render | £105–£145 per m²0% VAT | Most common choice for houses |
| Mineral wool system | £125–£170 per m²0% VAT | Non-combustible, vapour-open |
| Brick-slip finish over insulation | £185–£260 per m²0% VAT | Where a brick look is wanted |
| Three-bed semi, EPS + silicone (incl. scaffold) | £10,200–£17,7000% VAT | 80–100 m² of wall; depends on detailing and access |
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.
External wall insulation in Streatham: questions
Does external wall insulation cause damp?
Not when it is specified and detailed properly. Problems usually come from poor detailing: no starter track above the damp-proof course, gaps at cills and penetrations, or a vapour-closed system on a wall that needs to breathe. The survey checks moisture, ground levels and the wall type before a system is chosen.
Do I need planning permission for external wall insulation?
Often not for a house in England or Wales if the finish looks similar to the existing walls. You will usually need permission in a conservation area, on flats, on commercial buildings or where the appearance changes noticeably. Listed buildings need listed building consent. We check your address before quoting.
Does EWI need Building Regulations approval?
In England and Wales, usually. Insulating more than half of a wall's area, or more than a quarter of the building's whole external envelope, counts as renovating a thermal element, so building control needs to be involved and the wall should reach about 0.30 W/m²K where that's practical. Scotland and Northern Ireland have their own building standards processes.
Do you cover Streatham?
Yes — we survey and quote external wall insulation in Streatham (SW16) and nearby Mitcham, Brixton and Wimbledon, with a fixed written price before any work starts.