Typical planning cost£950–£4,600 by property type
Broader project rangeAbout £950 flat to £4,600 detached house
Planning figures are estimates rather than quotations. Live calculators combine dated UK benchmarks with clearly separated modelling assumptions such as region, size, condition and specification.
What affects the cost?
Cavity wall insulation cost is mainly determined by property size, accessible wall area, wall condition and the insulation system used.
- Property type and wall area
- Wall condition
- Mineral wool, beads or foam
- Access
- Survey findings
- Remedial work
Typical cost breakdown
Insulation material35–50%
Installation labour30–45%
Survey & access10–20%
Remedial allowance0–20%
Regional planning examples
The examples below apply our published modelling factor to the same national benchmark. They are not claimed as observed city-wide average quotes.
Sources used for this guide
Checkatrade
View source ↗How Much Does Cavity Wall Insulation Cost in 2026?
Published / checked: July 2026
Used for: Cavity wall insulation benchmarks by property type
Frequently asked questions
How much is cavity wall insulation for a semi-detached house?
A current UK planning benchmark is around £2,700.
How much is cavity wall insulation for a detached house?
A current UK benchmark is around £4,600, depending on wall area and condition.
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