Who Owns a Party Wall — and What Happens When Your Neighbour Starts Building

If your neighbour has started drilling, digging or knocking through and you've just heard the words “party wall” for the first time, this is the page you need. The short answer: a party wall is jointly used by both properties, and in most cases both owners have rights over it — which means neither of you can simply do what you like to it.

What is a party wall?

A party wall is a wall that stands on the land of two different owners, or that separates two buildings belonging to different owners — the wall between terraced or semi-detached houses is the classic example. The party wall meaning in law comes from the Party Wall etc. Act 1996, which also covers “party fence walls” (garden walls astride a boundary) and floors between flats. If a structure separates you from your neighbour, it is probably a party structure.

So who actually owns it?

Usually, each owner owns the part of the wall that stands on their land, with rights over the whole of it — the law treats it as shared for practical purposes. Your title deeds occasionally say otherwise, but for most homes the working answer is: you both do. That is exactly why the Party Wall Act exists — because work by one owner affects a structure the other owner relies on.

What it means when your neighbour starts building

If your neighbour is cutting into the shared wall (loft conversion beams, chimney breast removal), raising or underpinning it, building at the boundary line, or excavating within 3 metres of your home and deeper than your foundations, they are legally required to serve you a party wall notice before starting — usually one to two months before. You then have the right to consent, or to dissent and have a surveyor protect your interests, paid for by the neighbour doing the work.

If work has already started and you never received a notice, don't panic — but act. Photograph the shared wall inside your home today (that record matters if damage appears), then read our guide on party wall agreements or speak to a party wall surveyor about your position. An injunction can stop unlawful works, and a surveyor-led process usually resolves things without court.

What to do next

If you've received a notice: don't ignore it — our complete party wall agreement guide explains your three options. If works have started without one, or you're the one planning works, our RICS party wall surveyors — including local teams in London, Manchester and Chester — can serve notices, record condition and settle disputes on evidence. Ask us a party wall question →