Underfloor insulation for Caernarfon properties
If your property is in Caernarfon or the LL55 district or nearby Bangor, Porthmadog and Holyhead, it is within our Gwynedd coverage. It is roughly 6 miles south-west of Bangor.
We check ventilation as carefully as insulation in Caernarfon homes, because both matter for keeping a house dry. In Caernarfon homes this is often done on the same visit as a cavity fill, which saves a second trip.
On the rules side, if cavity wall insulation follows in Caernarfon, 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.
Keeping the void ventilated
Air bricks under a suspended floor must stay clear so the timbers stay dry. Insulation goes between the joists, not across the void, and gaps at skirtings are sealed to stop draughts.
What is included in Caernarfon
- Insulation between joists
- Floor void inspection
- Draught sealing at skirtings
- Boards relaid
Guide prices for Caernarfon
| Underfloor insulation guide prices | Guide price |
|---|---|
| Suspended timber floor, typical room | £795–£1,495 |
| Whole ground floor | £1,995–£3,995 |
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.
What happens next for a Caernarfon property:
Tell us about the property
Postcode, property type and what you would like done.
Free survey
Access, condition, existing insulation and ventilation checked.
Written result and price
What we recommend and a fixed price before any work.
Work and tidy-up
Fitted at an agreed time, with ventilation kept clear.