Loft insulation across Gwynedd
We cover 4 towns in Gwynedd: Bangor, Caernarfon, Holyhead and Porthmadog.
Where a Gwynedd home also has empty cavity walls, we can survey those at the same time. Small measures like this are often among the cheapest per pound saved, and they suit Gwynedd homes of every age.
Building Regulations in Wales
In Wales, filling an existing cavity is also notifiable building work under the Building Regulations as they apply in Wales. A registered installer normally self-certifies it through a competent person scheme; otherwise a building notice goes to your council's building control before work starts. Welsh rules can differ from England's, so the notification route is confirmed in writing on your quote.
Funding in Wales
- Warm Homes Nest offers free improvements, including insulation, to eligible low-income owner-occupiers and private renters; eligibility was widened to some households without means-tested benefits.
- Green Homes Wales has been piloting advice and interest-free loans for households above the Nest and ECO4 income thresholds.
- ECO4 runs until 31 December 2026 across Great Britain, including Wales.
Sources: Welsh Government: building work competent person schemes; CIGA: CWISC competent person scheme; Welsh Government: issues arising from cavity wall insulation installations; Welsh Government: warmer and more energy efficient homes (July 2026); GOV.UK: extending the ECO4 end date, government response.
What we check
Existing depth and condition, ventilation at the eaves, water tanks and pipes that need insulating, downlighters that need covers, and storage boarding that needs raising so insulation is not crushed.
What is included
- Depth and ventilation check
- Mineral wool to the recommended depth
- Tank and pipe lagging
- Loft hatch draught-proofing
Loft insulation prices in Gwynedd
| Loft insulation guide prices | Guide price |
|---|---|
| Loft insulation to 270mm, typical house | £395–£895 |
| Loft top-up from 100mm | £295–£595 |
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.
From enquiry to finish in Gwynedd:
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.