Party walls and boundaries

Does a home survey warn you that your extension plans need party-wall notice for excavation?

Only if you told the surveyor the plans and they chose to mention the Act. GOV.UK says excavation near and below a neighbour’s foundations is one of the works that can need notice. The survey is about the house as it stands. It does not design your extension, and it does not measure the neighbour’s foundations.

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?

People buy a house and a sketch of a side return together. The sketch is not in the Level 2 scope. If you want the surveyor to comment on whether a wall you hope to remove looks structural, agree that in writing. Even then they are not serving notice, and notice has to be given between two months and a year before the start.

Planning permission, building regulations and the Party Wall etc. Act are three separate regimes. GOV.UK says each can apply when the others do. Budget them separately. This page does not price an engineer, a planning fee or an award. A condition rating on the wall that is already there does not start the notice period and does not draw the neighbour’s foundations.

What should you ask your surveyor?

Did I tell you about future excavation, or are you only reporting the house as it is?
Can you see the neighbour’s foundation? Almost never, from this inspection.
Which regime are you pointing at: structure, regulations, or the Act?

What are the typical next steps?

Tell your designer and your solicitor about excavation near the boundary before you apply for anything.
Do not treat a survey paragraph as notice served.
Get an engineer if the structure is the question. Get party-wall advice if the Act is the question.

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

Does a neighbour’s verbal yes replace notice?

GOV.UK describes a notice procedure. Rely on your solicitor for whether a conversation is enough. The survey will not know it happened.

Is underpinning next door visible in this report?

Only if there is something to see on this side, such as old repair, and even then the survey may not know what was done next door.