Wall ties and cavity insulation
The seller has a boroscope photograph of the cavity. Is that the home survey?
No. It is someone else’s picture, taken on a day the surveyor may not have been present, of one small spot inside the wall. The home survey is what the surveyor saw and is willing to write. A photograph of a tie or of insulation does not become their inspection, and it does not let them certify the rest of the cavity.
Last reviewed 24 October 2026. Written for buyers in England and Wales unless this answer says otherwise. No named surveyor has signed this page. It is general guidance, not a report on your house, and not legal advice.
What is the fuller explanation?
A boroscope is a small camera in a drilled hole. One frame might show a tie, some mortar droppings, or a patch of fill. It does not show the next bay, the other elevation, or the state of ties that were not in shot. The seller, or a contractor the seller chose, controlled where the hole was drilled. A RICS home survey does not adopt that choice as its own test. The surveyor can look at the picture as information the seller handed over. They should say if they are not prepared to rely on it. You should not paste it into the report and call the ties inspected.
Ask the surveyor what they themselves saw on the outside of the wall, and whether they inspected the cavity at all. If the answer is no, the photograph remains the seller’s document. Ask who took it, when, and how many holes were made. One flattering frame is not a sample of the house. If you want a cavity inspection you can rely on, instruct it for yourself and agree the scope. Do not let the estate agent call the seller’s snapshot a specialist report. The home survey’s limitations still stand.
What should you ask your surveyor?
- Did you see inside the cavity yourself, or only this photograph?
- Will you rely on the photograph? If not, please say so.
- What defects on the outside of the wall did you see, regardless of the photo?
What are the typical next steps?
- Keep the seller’s photograph in the solicitor’s bundle, labelled as the seller’s.
- Do not tell a lender the ties were boroscoped by the home survey if they were not.
- If the ties matter, commission your own inspection rather than stretching one frame.
Costs vary with the building and with who you instruct. Where this page does not cite a published figure, ask the surveyor, a relevant specialist, or your solicitor for a written quote. Do not treat a forum average as the price.
Also asked about this
Can a clear photo cancel a crack the surveyor saw?
No. The crack was seen. The photo is one internal view. They answer different questions.
Should you drill more holes at the viewing to check the photo?
No. Do not drill someone else’s wall. A proper inspection is an instruction, not a DIY hole.