External wall insulation · Buckinghamshire
External wall insulation in Gerrards Cross
From Gerrards Cross to Chalfont St Peter, we price external wall insulation after a measured survey — no guesswork, and no work starts until the price is agreed in writing. We plan EWI in Gerrards Cross around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Free survey in SL9 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Gerrards Cross
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
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic
- Work happens outside, so you can live at home throughout
Before we quote in Gerrards Cross
Surveys in Gerrards Cross also cover the surrounding SL9 district and towns such as Chalfont St Peter and Uxbridge. Gerrards Cross is about 33 miles from Milton Keynes. 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.
Much of Buckinghamshire 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 Gerrards Cross, 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
- SL9
- County or area
- Buckinghamshire
- Nation
- England
- Nearby
- Chalfont St Peter, Uxbridge, Slough, Ruislip
England: planning and regulations
For a house in Gerrards Cross, 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.
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 Gerrards Cross
| 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
Enquiry
Send your postcode and a few details.
Measured survey
Walls, damp, eaves, cills and services recorded.
Written price
A fixed price with the specification attached.
Work and handover
Installed, inspected and documents handed over.
External wall insulation in Gerrards Cross: questions
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.
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 you cover Gerrards Cross?
Yes — we survey and quote external wall insulation in Gerrards Cross (SL9) and nearby Chalfont St Peter, Uxbridge and Slough, with a fixed written price before any work starts.