Cavity insulation for new builds and extensions for St Albans properties
We cover St Albans and the AL1 postcode district, including nearby Harpenden, Hatfield and Hemel Hempstead. St Albans is one of the main towns we cover in Hertfordshire.
Where a St Albans property has an extension or a conservatory, we check how the old and new walls meet, because that junction is often missed. For semi-detached and terraced homes in St Albans, cavity barriers are fitted where your wall meets your neighbour's so the fill stays on your side.
Every elevation is judged on its own exposure. 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.
On the rules side, in St Albans 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 St Albans
- Trays, closers and stop ends as drawn
- Coordination with your bricklayers
- Batts or boards to the specified U-value
- Photo record for building control
Guide prices for St Albans
| 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.
How it works in St Albans:
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.