What the surveyor checks
Wall construction and thickness at window reveals; cavity width and debris with a borescope; brickwork, pointing, render, sills, gutters and downpipes; signs of damp inside and out; air bricks and flues; joins with neighbours and extensions; and the exposure of each elevation to wind-driven rain.
What you get
A clear result: suitable, suitable after repairs, or not suitable. Where repairs are needed first, they are listed and priced separately so you can choose who does them. The survey is free when you are getting an install quote.
What is included
- Photo-backed written result
- Cavity width and debris check
- Exposure assessment by elevation
- Repairs list where needed
- Fixed install price where suitable
Cavity wall suitability survey prices
| Cavity wall suitability survey guide prices | Guide price |
|---|---|
| Suitability survey with an install quote | Free |
| Standalone survey report (no install quote) | £145–£245 |
The survey is free with an install quote. A standalone report is not insulation, so it is normally standard-rated for VAT; guide prices include VAT. 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).