Cavity Wall Insulation Cost UK

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.

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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.

London£1,200–£5,900

Manchester£890–£4,300

Birmingham£930–£4,500

Glasgow£900–£4,350

Cardiff£860–£4,200

Sources used for this guide

Checkatrade

How Much Does Cavity Wall Insulation Cost in 2026?

Published / checked: July 2026

Used for: Cavity wall insulation benchmarks by property type

View source ↗

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.

Related costs

Cost guide

Home insulation

Current UK loft and cavity-wall insulation costs by property type, with per-square-metre material benchmarks and suitability notes.

£654–£1,206 for loft quilt · £950–£4,600 for cavity wallsView guide →Cost guide

External wall insulation

UK external wall insulation costs per square metre and by property type.

£150–£200 per m² installedView guide →Cost guide

Heat pump

Current UK heat-pump costs for air-to-air, air-to-water and ground-source systems, with 2026 Boiler Upgrade Scheme grant values shown separately.

About £15,000 for air-to-water before grantView guide →