Existing insulation and guarantee check across Gwynedd
We cover 4 towns in Gwynedd: Bangor, Caernarfon, Holyhead and Porthmadog.
Before any material is chosen, exposure is checked. Parts of Gwynedd 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.
A survey in Gwynedd gives you facts before anyone drills: what the wall is, what is in the cavity and whether it is sound. The written result for your Gwynedd property is plain English: what we found, what it means and what, if anything, to do next.
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.
Sources: Welsh Government: building work competent person schemes; CIGA: CWISC competent person scheme; Welsh Government: issues arising from cavity wall insulation installations.
How to tell if a house already has cavity insulation
Look for a regular pattern of small patched holes in the mortar joints, often about a metre apart. Check the EPC, which may say 'filled cavity'. Ask the seller for a guarantee. The reliable answer is a borescope check, because patched holes can be from a fill that was later removed and EPCs are sometimes wrong.
What is included
- Borescope checks
- Visual check of walls and patched holes
- Damp signs inside and out
- Guidance on tracing a guarantee
- Short written report
Existing insulation and guarantee check prices in Gwynedd
| Existing insulation and guarantee check guide prices | Guide price |
|---|---|
| Existing insulation and guarantee check | £145–£245 |
This work is not insulation, so it is normally standard-rated for VAT. Guide prices include VAT where it applies. 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.
How it works in Gwynedd:
Get in touch
Online, by phone or WhatsApp.
Your price
Confirmed in writing before you book.
The visit
Carried out at an agreed time, with photos of what we find.
Your report
Plain English, with any follow-on work quoted separately.