Party wall notice checker
The Party Wall etc. Act 1996 catches far more projects than people expect — including extensions built entirely on your own land. Two questions will tell you where you stand.
Last updated July 2026 · built by working UK builders
Guidance on the Party Wall etc. Act 1996, which applies in England and Wales. Scotland and Northern Ireland have no equivalent statute — common law and title conditions apply instead. This is not legal advice.
What the Act actually covers
Three separate things, each with its own notice and its own notice period.
Section 1 — a new wall at the boundary
Building a new wall on or astride the line of junction. One month's notice.
Section 2 — work to an existing party structure
Cutting in, raising, thickening, underpinning, removing chimney breasts, taking a beam into the wall. Two months' notice. This is the one loft conversions and side-return extensions trigger.
Section 6 — excavation near a neighbouring building
Within 3 metres and deeper than their foundations, or within 6 metres and deep enough to cut a line drawn down from their foundations at 45 degrees. One month's notice. This is the one that catches people who assumed that building on their own land meant the Act did not apply.
What happens after you serve
- 14 days. The adjoining owner consents in writing, dissents, or says nothing. Silence counts as dissent — this surprises everyone.
- If they consent, you are done. Take your own photographic schedule of condition anyway, before a single tool comes out of the van.
- If they dissent, surveyors are appointed. One agreed surveyor acting for both of you is cheaper and usually just as protective. Two surveyors means two fees, both payable by you.
- The award. A binding document setting out what work may be done, when, with a schedule of condition of the neighbour's property. Typically four to eight weeks.
Why the award is worth having
The schedule of condition is the part that protects you. It records, with photographs, every existing crack and defect in the adjoining property before you start. Without it, any damage the neighbour notices during your build becomes your problem to disprove — and disproving it is considerably more expensive than the surveyor would have been.
How to make it painless
- Talk to your neighbour before the notice arrives. A formal legal document landing on the mat unannounced is how disputes start.
- Serve early. Three months before you want to break ground, not three weeks.
- Offer an agreed surveyor. It halves the cost and removes the adversarial framing.
- Share the drawings. People object to uncertainty far more than to extensions.
- Put the working hours, parking and skip arrangements in writing yourself, before anyone asks.
Frequently asked questions
Do I need a party wall agreement for an extension?
It depends on where you dig, not on where you build. If you excavate within 3 metres of a neighbouring building and go deeper than their foundations, you must serve notice. Most rear extensions on terraced and semi-detached houses do trigger this, even when the extension itself is entirely on your own land.
How long does the party wall process take?
Two months’ notice for work to a party structure, one month for excavation or a new wall at the boundary. The neighbour then has 14 days to consent or dissent. If they dissent, or say nothing, surveyors are appointed and an award typically takes a further 4–8 weeks. Start the process at least three months before you want to build.
What happens if my neighbour ignores the notice?
Silence counts as dissent. After 14 days a dispute is deemed to have arisen, and you must appoint surveyors — either one agreed surveyor for both of you, or one each. You pay the fees. This is why serving notice early and talking to your neighbour first is worth real money.
Who pays for the party wall surveyors?
The building owner — you — normally pays, because you are the one benefiting from the work. Expect £1,200–£3,500 for a straightforward award, more in London and more if there are several adjoining owners. An agreed single surveyor is significantly cheaper than one each.
What if I just build without serving notice?
Your neighbour can seek an injunction stopping the work, which is far more expensive and far more disruptive than doing it properly. You also lose the protection of the schedule of condition, which means any pre-existing crack in their house becomes an argument you are likely to lose.