Cavity insulation for new builds and extensions for Stevenage properties
We cover Stevenage and the SG1 postcode district, including nearby Hitchin, Letchworth Garden City and Welwyn Garden City. It is around 12 miles north-east of St Albans.
Where a Stevenage property has an extension or a conservatory, we check how the old and new walls meet, because that junction is often missed. Stevenage properties with rendered or painted walls get a closer look at the outer finish, because cracked render can let rain behind it.
Local weather affects which walls can be filled. Much of Hertfordshire 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.
As for paperwork, in Stevenage 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 Stevenage
- Photo record for building control
- Batts or boards to the specified U-value
- Coordination with your bricklayers
- Clean-cavity working
Guide prices for Stevenage
| 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.
From enquiry to finish in Stevenage:
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.