Cavity wall insulation for London properties
London sits in Greater London. We work across the EC1A district, including nearby Pimlico, Islington and Camden Town.
London properties with rendered or painted walls get a closer look at the outer finish, because cracked render can let rain behind it. For semi-detached and terraced homes in London, 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 compliance, in London 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 happens on the day?
Holes of around 22mm are drilled in the mortar joints in a set pattern, roughly a metre apart. The insulation is blown in from the bottom up until each section is full, then every hole is filled with colour-matched mortar. Air bricks and flues are protected, and a cavity barrier is fitted where your wall joins a neighbour's.
What is included in London
- Cavity barriers at party walls
- Certified mineral wool or bonded bead system
- Borescope check where the cavity is in doubt
- Building regulations route for your nation, confirmed in writing
Guide prices for London
| Cavity wall insulation guide prices | Guide price |
|---|---|
| Detached house | £2,295–£3,795 |
| Semi-detached house | £1,495–£2,495 |
| End-terrace house | £1,295–£2,195 |
| Detached bungalow | £1,295–£2,195 |
| Semi-detached bungalow | £895–£1,595 |
| Mid-terrace house | £795–£1,395 |
No VAT is charged on installing insulation in homes until 31 March 2027 (then 5%). 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 London:
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.