External wall insulation · Hertfordshire
External wall insulation in Bishop's Stortford
Quotes for external wall insulation in Bishop's Stortford list the system, the detailing and the VAT position in writing, so you know exactly what's included. Whole-house jobs and single elevations are both quoted in Bishop's Stortford; a cold gable or rear wall can be done on its own where it suits.
- Free survey in CM23 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Bishop's Stortford
Postcode, service and a phone number is all we need.
What you get
- Installing wall insulation in homes is currently zero-rated for VAT until 31 March 2027
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic
- Typically takes a 225mm solid brick wall from around 2.1 W/m²K to about 0.30 W/m²K with 90–110mm of board
- Covers tired brick, pebble dash or failing render with a new finish

Before we quote in Bishop's Stortford
As well as Bishop's Stortford itself, we quote in Harlow, Hoddesdon and Hertford. Bishop's Stortford sits around 28 miles from Watford. The East of England has a mix of post-war estates, inter-war semis and older solid brick and flint cottages, with some system-built council homes on post-war estates.
Much of Hertfordshire 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 Bishop's Stortford, 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
- CM23
- County or area
- Hertfordshire
- Nation
- England
- Nearby
- Harlow, Hoddesdon, Hertford, Cheshunt
Planning and building control in England
For a house in Bishop's Stortford, 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.
What finish can I have?
Most EWI is finished in a thin-coat silicone render in a through-coloured shade, with a 1–2mm grain. Acrylic, mineral (painted), dry-dash and brick-slip finishes are also available. Where planning wants a brick look, brick slips over the insulation keep the street appearance.
External wall insulation prices in Bishop's Stortford
| 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 Bishop's Stortford: 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 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.
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 Bishop's Stortford?
Yes — we survey and quote external wall insulation in Bishop's Stortford (CM23) and nearby Harlow, Hoddesdon and Hertford, with a fixed written price before any work starts.