Blown mineral wool insulation for Cardiff properties
Cardiff is among the towns we cover in South Glamorgan, alongside Penarth and Barry. Cardiff is one of the main towns we cover in South Glamorgan.
Most Cardiff houses built from the 1920s onwards have cavity walls, but the survey still checks each one: cavity width, debris, the condition of the brickwork and how exposed each wall is. A suitable wall in Cardiff is usually filled in a single day from outside, with drill holes made good to match the pointing.
Local weather affects which walls can be filled. Parts of South Glamorgan face some of the heaviest wind-driven rain in the UK, especially exposed coastal and upland sites. Here the survey is stricter: some walls suit only certain certified systems, and some should not be filled at all.
On the rules side, in Cardiff filling a cavity is notifiable work under the Building Regulations as they apply in Wales, usually self-certified through a competent person scheme.
Funding in Wales
In Wales, Warm Homes Nest offers free improvements to eligible low-income households, and ECO4 runs to 31 December 2026.
Sources: Welsh Government: warmer and more energy efficient homes (July 2026); GOV.UK: extending the ECO4 end date, government response.
Why choose mineral wool?
Mineral wool fibres are treated to shed water, so moisture that gets into the outer leaf runs down the cavity rather than tracking across. It is classed as non-combustible, which matters for some flats and taller buildings, and it is usually the lower-cost certified option.
What is included in Cardiff
- Cavity barriers where needed
- Density and drill pattern recorded
- Making good to the mortar colour
- Regulations route and guarantee named on the quote
Guide prices for Cardiff
| Blown mineral wool insulation guide prices | Guide price |
|---|---|
| Detached house | £1,895–£3,395 |
| Semi-detached house | £1,295–£2,195 |
| End-terrace house | £1,095–£1,895 |
| Detached bungalow | £1,095–£1,895 |
| Semi-detached bungalow | £795–£1,395 |
| Mid-terrace house | £795–£1,295 |
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.
The steps for blown mineral wool insulation in Cardiff:
Get in touch
Online, by phone or WhatsApp, whichever suits you.
Survey visit
The surveyor checks each wall and looks into the cavity where needed.
Your result in writing
What we found, what it means, and a fixed price if work is needed.
Booked work
Carried out by the installer named on your quote, with their scheme registrations.