Cavity insulation for new builds and extensions for Coulsdon properties
Our Greater London coverage takes in Coulsdon (CR5) and nearby Purley, Wallington and Sutton. It is roughly 13 miles south of London.
Where a Coulsdon property has an extension or a conservatory, we check how the old and new walls meet, because that junction is often missed. If a wall in Coulsdon 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.
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 Coulsdon 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.
Extensions that join an older house
Where an extension meets an existing cavity wall, the junction is a weak point. We can borescope and fill the existing wall at the same time so the old and new walls perform together.
What is included in Coulsdon
- Photo record for building control
- Batts or boards to the specified U-value
- Trays, closers and stop ends as drawn
- Clean-cavity working
Guide prices for Coulsdon
| 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 Coulsdon:
Tell us about the property
Postcode, property type and what you need.
Free survey
Walls, cavity, condition and exposure checked and photographed.
Written result and price
Suitable, suitable after repairs, or not suitable, with a fixed price.
Work and paperwork
Installation, making good, and the regulations and guarantee paperwork.