External wall insulation · Greater London
External wall insulation in Hanworth
If you're planning external wall insulation in Hanworth, start with a free survey: we measure, check the walls and confirm planning and building control for your address. We plan EWI in Hanworth around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Free survey in TW13 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Hanworth
Postcode, service and a phone number is all we need.
What's included
- Covers tired brick, pebble dash or failing render with a new finish
- Cills, pipes, vents, meter boxes and the roofline detailed as part of the job
- Work happens outside, so you can live at home throughout
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board
Before we quote in Hanworth
We also cover Feltham and Sunbury-on-Thames, close to Hanworth. 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.
Whole-house jobs and single elevations are both quoted in Hanworth; a cold gable or rear wall can be done on its own where it suits.
- Postcode district
- TW13
- County or area
- Greater London
- Nation
- England
- Nearby
- Feltham, Sunbury-on-Thames, Hounslow, Ashford (Surrey)
Permissions in England
Before quoting in Hanworth, 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 Hanworth
| 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.
From enquiry to finished wall
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 Hanworth: questions
Can EWI go over pebble dash?
Usually yes. The dash is tested for adhesion and hollow areas; sound dash can be insulated over with additional mechanical fixings, while loose areas are removed first.
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.
How much does external wall insulation cost?
Our guide price for EWI is £105–£170 per m² of wall depending on the system, plus scaffolding. A typical three-bed semi with EPS and silicone render comes to roughly £10,200–£17,700 for the whole house, including scaffold. Installing insulation in a home is zero-rated for VAT until 31 March 2027, so that's the total. You get a fixed written price after a free survey.
Do you cover Hanworth?
Yes — we survey and quote external wall insulation in Hanworth (TW13) and nearby Feltham, Sunbury-on-Thames and Hounslow, with a fixed written price before any work starts.