Cavity insulation for new builds and extensions for Northampton properties
Northampton is among the towns we cover in Northamptonshire, alongside Wellingborough, Daventry and Rushden. Northampton is one of the main towns we cover in Northamptonshire.
If a wall in Northampton is not suitable, for example because of an undiagnosed damp patch or a very exposed gable, you are told so in writing with the reason. Most Northampton houses built from the 1920s onwards have cavity walls, but the survey still checks each one: cavity width, debris, the condition of the brickwork and how exposed each wall is.
Local weather affects which walls can be filled. Much of Northamptonshire sits in the more sheltered driving-rain zones of the UK, which widens the choice of fill. Exposed elevations, coastal sites and high ground still get checked wall by wall.
On the rules side, in Northampton filling a cavity is notifiable building work and needs a building notice or competent-person self-certification.
Funding in England
In England, ECO4 runs to 31 December 2026 and Warm Homes: Local Grant supports low-income households through councils.
Sources: GOV.UK: extending the ECO4 end date, government response; GOV.UK: Warm Homes Plan.
What we work from
Your architect's or designer's specification and the energy calculation for the job. We match the product, thickness and fixing to that spec, keep cavities clean as the walls rise, and fit cavity trays, closers and stop ends where shown so the building control inspection goes smoothly.
What is included in Northampton
- Photo record for building control
- Clean-cavity working
- Batts or boards to the specified U-value
- Coordination with your bricklayers
Guide prices for Northampton
| Cavity insulation for new builds and extensions guide prices | Guide price |
|---|---|
| Full-fill batts supplied and fitted, per m² | £9–£16 |
| Partial-fill boards supplied and fitted, per m² | £14–£26 |
Prices are shown before any VAT; the VAT treatment for new-build work is confirmed on your quote. Guide ranges only: the fixed price is confirmed in writing before any work starts, and anything that could not be seen at survey is agreed with you first.
The steps for cavity insulation for new builds and extensions in Northampton:
Send your details
A minute online, or call the free number.
We check the walls
Construction, cavity width, debris, damp and wind-driven rain exposure.
You decide
Plain-English result and a fixed price, with no pressure to book.
Job done properly
Holes made good, paperwork handed over, guarantee details confirmed.