What the Party Wall etc. Act actually covers

The Party Wall etc. Act 1996 sounds grander than it is. It doesn't apply to every bit of building work near a neighbour — only to specific activities. If your extension involves any of the following, the Act is in play: work to a party wall itself (a wall shared between two properties, or a wall standing astride the boundary line), building a new wall on or at the boundary, or excavating within a set distance of a neighbour's structure.

That last one catches people out. Digging foundations for a rear extension often triggers the Act even when you're nowhere near the shared wall. The rules bite when you excavate within three metres of a neighbour's building and go deeper than their foundations, or within six metres if your excavation cuts a line drawn down at 45 degrees from the bottom of their footings. In practice, most residential extensions of any depth sit inside that triangle.

Not sure whether you're caught? Compare your proposed foundation depths with your neighbour's. If yours are deeper and you're within those distances, assume you are.

When to serve notice — and the deadlines that matter

Notices are the mechanism the Act uses to give neighbours a formal say. Get the timing wrong and you may have to start again, or find yourself in a dispute you could have avoided.

• Two months' notice for work to an existing party wall or party structure — cutting in for steels, raising a wall, underpinning, damp-proofing.
• One month's notice for excavation works near a neighbour's building, and for building a new wall at the boundary.
• 14 days is the window for your neighbour to respond. Silence after that counts as a dispute, which sounds dramatic but is really just a procedural trigger.

Notices must be in writing, dated, and describe the work clearly. They should be served on the owner of the adjoining property — which for leasehold flats means the freeholder or the leaseholder, depending on the lease. If a property is empty or the owner is hard to trace, the Act allows notice to be served on the occupier and fixed to the building.

One surveyor or two? How the appointment works

If your neighbour agrees in writing to the work, you can proceed and simply record that agreement. More often, they'll want the protection of a surveyor — and that's entirely reasonable.

The usual route is a single agreed surveyor, jointly appointed and paid for by the person doing the building work. It's cheaper, quicker and avoids two sets of fees. If either side prefers their own representative, each appoints a surveyor and those two pick a third to act as chairman if they can't agree. That's the "two plus one" arrangement, and it's the most common in practice.

The surveyors prepare a schedule of condition before work starts, recording the state of the neighbour's property so there's a fair baseline if cracks or damage appear later. They then issue an award — a written document setting out how the work is done, what protections are put in place, and who pays for what.

What the award does and doesn't do

An award isn't planning permission and it isn't building regulations approval. It deals only with party wall matters. Don't treat it as a substitute for either.

What it can cover:

• The times and hours when work may proceed.
• Protective measures — temporary support, monitoring, a schedule of condition.
• Access for the surveyor and for the works themselves.
• Making good any damage caused by the work.
• Who bears the costs, which is normally the building owner.

Your neighbour's surveyor's fees are usually paid by the person carrying out the work, which is one more reason to keep things amicable. Disagreements over fees can themselves be resolved by the surveyors.

If your neighbour objects or simply goes quiet

Objections are usually about noise, mess, or the fear of damage — not the work itself. Address them early, before notice is served. A short conversation, a copy of the drawings and a clear timeline defuses most of it.

If a formal objection comes back, or no response arrives within 14 days, you're in "dispute" under the Act. That doesn't mean lawyers and tribunals. It means surveyors are appointed and the process continues. You'll need to cover the reasonable fees, and you'll need to wait for an award before starting the relevant work.

Ignoring the Act is far more expensive than following it. Building without a valid notice or award can lead to an injunction, and a neighbour can seek damages for their losses. In the worst cases, finished work has to be undone.

Keeping it civil: practical habits that help

• Tell neighbours about your plans before the notice lands on the doormat.
• Serve notices early — two months is a minimum, not a target.
• Photograph everything before work begins, and keep a copy with both sides.
• Give at least 14 days' notice before accessing their property for the works.
• Reply to their surveyor promptly; dragging things out costs everyone.

Extensions are disruptive by nature. A clear process, decent communication and a surveyor who explains things in plain English turn a potential feud into a paperwork exercise. Get it right at the start and you can get on with the building.