Cavity insulation for new builds and extensions for Finchley properties
Finchley is among the towns we cover in Greater London, alongside Muswell Hill, Cricklewood and Kilburn. It is around 7 miles north-west of London.
Where a Finchley 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 Finchley, 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 Greater London 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 Finchley 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 Finchley
- Coordination with your bricklayers
- Clean-cavity working
- Trays, closers and stop ends as drawn
- Batts or boards to the specified U-value
Guide prices for Finchley
| 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 Finchley:
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.