Cavity wall insulation for Southampton properties
Our Hampshire coverage takes in Southampton (SO14) and nearby Hythe, Totton and Eastleigh. Southampton is one of the main towns we cover in Hampshire.
A suitable wall in Southampton is usually filled in a single day from outside, with drill holes made good to match the pointing. If a wall in Southampton 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.
Wind-driven rain is the first thing the surveyor weighs up. Hampshire has a mix of moderate and more exposed sites. Hilltop, coastal and west-facing walls take the brunt of wind-driven rain, so the survey records exposure for each elevation before a material is chosen.
In terms of approvals, in Southampton 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 Southampton
- Building regulations route for your nation, confirmed in writing
- Drilling, filling and colour-matched making good
- Guarantee and installer named on your quote
- Cavity barriers at party walls
Guide prices for Southampton
| 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 Southampton:
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.