When a borescope check helps
Before filling, to confirm the cavity is empty and clean. Before buying a house, to see if the EPC's claim of 'filled cavity' is true. When damp has appeared and you need to know whether the fill is wet or bridged. Before a top-up, to map which panels are empty.
How many holes?
Enough to be representative: typically several per elevation, plus targeted checks below windows, at corners and near any damp patches. Each one is photographed and logged.
What is included
- Inspection points on each elevation
- Photos of each point
- Fill type and condition noted
- Holes made good
- Written summary
Borescope cavity inspection prices
| Borescope cavity inspection guide prices | Guide price |
|---|---|
| Borescope inspection, house | £145–£245 |
| Borescope inspection, block or large building | £295–£595 |
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.
Rules and funding by nation
The building regulations route and the funding schemes differ between England, Wales, Scotland and Northern Ireland. The local pages for your area explain the rules where you are; in short:
- England: Filling a cavity is notifiable building work and needs a building notice or competent-person self-certification.
- Wales: Filling a cavity is notifiable work under the Building Regulations as they apply in Wales, usually self-certified through a competent person scheme.
- Scotland: No building warrant is needed for insulation within a wall, but the work must meet the building standards.
- Northern Ireland: Inserting cavity wall insulation needs a building control application to the council before work starts.
Sources: Energy Saving Trust: cavity wall insulation; Planning Portal: cavity wall insulation and building regulations; Welsh Government: building work competent person schemes; HMRC: VAT on energy-saving materials (Notice 708/6).