Cavity insulation top-up for Blackheath properties
Blackheath is among the towns we cover in Greater London, alongside Greenwich, Catford and Eltham. It is roughly 6 miles south-east of London.
For semi-detached and terraced homes in Blackheath, cavity barriers are fitted where your wall meets your neighbour's so the fill stays on your side. If a wall in Blackheath 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.
Before any material is chosen, exposure is checked. 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 Blackheath 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.
When a top-up is not enough
If the existing fill is wet, contaminated with debris or breaking down, adding more on top can make things worse. In that case we tell you the honest option, which may be partial or full removal and refill.
What is included in Blackheath
- Targeted fill with a compatible system
- Written result with photos
- Map of filled and empty sections
- Borescope survey at several points
Guide prices for Blackheath
| Cavity insulation top-up guide prices | Guide price |
|---|---|
| Detached house | £1,295–£2,295 |
| Semi-detached house | £795–£1,495 |
| End-terrace house | £695–£1,295 |
| Detached bungalow | £695–£1,295 |
| Semi-detached bungalow | £595–£995 |
| Mid-terrace house | £595–£995 |
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.
What happens next for a Blackheath property:
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.