Cavity insulation for new builds and extensions for Carshalton properties
We cover Carshalton and the SM5 postcode district, including nearby Wallington, Sutton and Mitcham. It is around 10 miles south of London.
If a wall in Carshalton 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. For semi-detached and terraced homes in Carshalton, cavity barriers are fitted where your wall meets your neighbour's so the fill stays on your side.
Local weather affects which walls can be filled. 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.
In terms of approvals, in Carshalton 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 Carshalton
- Batts or boards to the specified U-value
- Trays, closers and stop ends as drawn
- Coordination with your bricklayers
- Photo record for building control
Guide prices for Carshalton
| 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.
What happens next for a Carshalton property:
Get in touch
Online, by phone or WhatsApp, whichever suits you.
Survey visit
The surveyor checks each wall and looks into the cavity where needed.
Your result in writing
What we found, what it means, and a fixed price if work is needed.
Booked work
Carried out by the installer named on your quote, with their scheme registrations.