External wall insulation · Northamptonshire
External wall insulation in Northampton
Homeowners and landlords in Northampton can get a free survey and a fixed written quote for external wall insulation, covering NN1 and the surrounding area. Whole-house jobs and single elevations are both quoted in Northampton; a cold gable or rear wall can be done on its own where it suits.
- Free survey in NN1 and nearby
- Guide price from £105 per m² + scaffold, 0% VAT
- Fixed written price before work starts
Free survey in Northampton
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
- Cills, pipes, vents, meter boxes and the roofline detailed as part of the job
- Boards chosen for the wall: EPS, mineral wool, wood fibre or phenolic

Northampton: walls, weather and approvals
We cover Northampton and nearby Wellingborough, Daventry and Rushden. Housing in the East Midlands includes Victorian terraces in the towns and cities, plenty of inter-war semis and post-war council estates, some of them system-built.
Much of Northamptonshire 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.
We plan EWI in Northampton around the details that cause trouble later — cills, eaves, downpipes and the base of the wall above the damp-proof course.
- Postcode district
- NN1
- County or area
- Northamptonshire
- Nation
- England
- Nearby
- Wellingborough, Daventry, Rushden, Kettering
Permissions in England
For a house in Northampton, 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.
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.
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 Northampton
| 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
Tell us about the property
Use the quote tool or form, or call. Photos help.
Free survey
We measure, check the walls and confirm approvals.
Fixed written quote
System, details, access, exclusions and VAT in writing.
Installation
Scheduled for suitable weather, with a clear programme.
External wall insulation in Northampton: questions
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.
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 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 Northampton?
Yes — we survey and quote external wall insulation in Northampton (NN1) and nearby Wellingborough, Daventry and Rushden, with a fixed written price before any work starts.