Calculate your home insulation cost
Loft insulation cost by property type in London
UK £654£700
UK £825£850
UK £1,206£1,250
UK £1,205£1,250
Cavity wall insulation by property type
UK £950£1,000
UK £1,800£1,900
UK £2,700£2,850
UK £2,400£2,550
UK £4,600£4,850
Cavity insulation rates
What can change a real London quote?
- Loft or cavity-wall insulation
- Property type and measured area
- Existing insulation depth
- Glass wool, mineral wool, EPS or foam specification
- Wall exposure, condition and damp risk
- Access and removal of old insulation
- Repairs identified by the survey
Local planning considerations
Dense access, parking, deliveries and contractor overheads can widen the spread between quotations, so use the figures as an early budget rather than a quote.
- Allow separately for parking, loading, permits or restricted delivery windows where a property has difficult street access.
- Flats and managed buildings can add landlord, freeholder or building-management requirements that are outside a basic works estimate.
- Party-wall, structural and access costs should be checked independently on extensions, lofts and major internal alterations.
How the regional model works
The broad London factor is 1.28×, while the live insulation calculator uses 1.056×. Only 20% of the broad regional difference is applied because insulation jobs contain a meaningful material component and the published national benchmarks already span property size and system type.
Sources
UK loft and cavity wall insulation cost guidance
Published / checked: Checked September 2026
Used for: Loft insulation property benchmarks and cavity wall per-m² costs
Frequently asked questions
How much does home insulation cost in London in 2026?
Current loft-quilt examples are £654 for a terrace, £825 for a semi-detached house, £1,206 for a detached house and £1,205 for a bungalow. The model gives about £850 as the typical semi-detached loft reference in London.
How much does cavity wall insulation cost in London?
Current national property examples range from £950 for a flat to £4,600 for a detached house, with £2,700 for a semi. The model gives about £2,850 for the semi-detached example.
What are the current cavity-wall rates per square metre?
Glass wool is about £25–£30 per m² nationally and polyurethane foam about £30–£65 per m². The modelled London rates are £26–£32 per m² and £32–£69 per m² respectively.
Does every home qualify for cavity wall insulation?
No. Wall construction, cavity width, exposure, damp, cracks and wall-tie condition should be checked before installation. A suitability survey is important.