When do you need a party wall agreement, and how do you get one?

If you are digging foundations near a neighbour's property, cutting into a shared wall, or building right up to the boundary, the Party Wall etc. Act 1996 probably applies. It is a notice regime, not a planning matter, and it runs in parallel with everything else.

The three types of notifiable work

Section 1 — building a new wall on, or up to, the line of junction with a neighbour. One month's notice.

Section 2 — work directly to an existing party wall or party structure: cutting in for a beam, inserting a damp course, removing a chimney breast, raising or underpinning the wall, demolishing and rebuilding it. Two months' notice.

Section 6 — excavating within 3m of a neighbouring structure to a depth below its foundations, or within 6m if your excavation cuts a 45-degree line down from theirs. One month's notice. Most rear extensions on terraces and semis trigger this one.

Internal work that does not touch a shared structure — a new stud wall, replastering, a new kitchen — is not notifiable.

What the process looks like

1. Identify every adjoining owner. That includes freeholders and long leaseholders, and both neighbours if you are mid-terrace.
2. Serve a valid notice in writing, with the correct notice period, describing the work and including sections and plans for excavation work.
3. The neighbour has 14 days to respond. They can consent in writing, dissent and appoint their own surveyor, or dissent and agree to a single "agreed surveyor" acting impartially for both.
4. Silence counts as dissent — a dispute is deemed to have arisen, and surveyors must be appointed.
5. The surveyor(s) prepare a schedule of condition of the neighbour's property and then serve a Party Wall Award setting out how, when and under what safeguards the work proceeds.

Cost and timing

• Consent in writing: no surveyor cost.
• Agreed surveyor: commonly £1,000-£2,000 per neighbour.
• Two surveyors: commonly £2,000-£4,000 per neighbour, and the building owner normally pays both sets of fees.
• Time: allow 8-12 weeks from serving notice to holding an Award. Serve early, ideally alongside the planning application, and never after the contractor is booked.

An Award is generally treated as valid for 12 months from service of the notice, so do not serve so early that it expires.

Common mistakes

• Assuming a friendly chat replaces a written notice. It does not.
• Serving notice on the occupier rather than the owner.
• Getting the notice period wrong — a Section 2 notice is two months, not one.
• Skipping the schedule of condition. Without it, you have no defence against a claim that your work caused a pre-existing crack.
• Starting work before the Award is served. Your neighbour can seek an injunction, and stopping a live site is expensive.

If your neighbour refuses

They cannot veto notifiable work. Dissent simply moves you into the surveyor process. The Award decides how the work is done, not whether it happens. Refusing to appoint a surveyor allows you to appoint one on their behalf after a further 10-day notice.

Who to use

Use a party wall surveyor who is a member of the Faculty of Party Wall Surveyors or RICS. Your architect or structural engineer will usually tell you which notices apply from the drawings.

Next step

BuildWise Workspace places party wall notices on your programme with the correct lead-in times, so the Award lands before your contractor is due to start rather than three weeks after.