Calculate your home insulation cost
Loft insulation cost by property type in Cardiff
UK £654£650
UK £825£800
UK £1,206£1,200
UK £1,205£1,200
Cavity wall insulation by property type
UK £950£950
UK £1,800£1,750
UK £2,700£2,650
UK £2,400£2,350
UK £4,600£4,500
Cavity insulation rates
What can change a real Cardiff 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
For grants and energy schemes, verify the current Wales-specific eligibility rules before relying on any support assumption.
- Use Wales-specific planning, building-control and energy-scheme information where the rules differ from England.
- Terraced or constrained urban properties can add access, waste and scaffold costs that are not captured by the regional factor.
- Drainage, roof and external-work scopes should be based on the property condition rather than a generic city assumption.
How the regional model works
The broad Wales factor is 0.91×, while the live insulation calculator uses 0.982×. 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 Cardiff 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 £800 as the typical semi-detached loft reference in Cardiff.
How much does cavity wall insulation cost in Cardiff?
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 £2,650 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 Cardiff rates are £25–£29 per m² and £29–£64 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.