Party Wall Notices: What You Need to Serve, and When

A party structure notice covers work to a shared wall itself — cutting in to take a steel beam, raising it, underpinning it, or removing a chimney breast attached to it. This is the most common notice on a London terrace, and it requires two months before work can begin.

A line of junction notice applies when you build a new wall up to or astride the boundary line where none exists. It requires one month.

An adjacent excavation notice applies when you excavate within 3 metres of a neighbouring structure and go deeper than its foundations, or within 6 metres where the excavation cuts a line drawn down at 45 degrees from their foundation. It also requires one month.

The periods are calendar months and run from the date the notice is served, not the date you posted it or decided to do the work. This is why party wall matters should be started early — it is one of the most common reasons a start date slips.

A neighbour can consent in writing, in which case the process ends there and you can proceed on the agreed date. They can dissent, which means surveyors are appointed and a party wall award is drawn up setting out how the work will be done and recording the condition of their property beforehand.

Or they can do nothing. Silence is not consent — after 14 days without a response, a dispute is deemed to have arisen and the surveyor route begins automatically. Many homeowners assume no reply means no objection; it means the opposite.

Where a neighbour dissents they may appoint their own surveyor, or both parties may agree on a single "agreed surveyor". The building owner normally pays the reasonable surveyor costs, which is worth budgeting for at the outset rather than discovering mid-project.

It is not planning permission and it is not Building Regulations approval. You can have all three obligations on one project and satisfying one does nothing for the others.

It also does not give a neighbour a veto. A neighbour cannot stop reasonable work that falls under the Act; the dissent route determines how the work is done and protects their property, not whether it happens.

Proceeding without serving notice where notice was required leaves you exposed to an injunction and to claims for any damage, with the burden falling on you rather than on them. It is a legal process worth doing properly, and it is normally a matter for a party wall surveyor rather than the builder.