Neighbour digging foundations next to my house — what are my rights?
Last updated: 30 July 2026
If a neighbour digs within 3 metres of your home and deeper than your foundations, the law says they must tell you first — in writing, a month in advance, with drawings. Here's how the two distance rules work, what the notice must contain, and what to do if the digger next door hasn't sent one.
The two tests: 3 metres and 6 metres
Section 6 of the Party Wall etc. Act 1996 covers excavation — foundations for an extension, a basement dig, piling, a lift pit. Two tests decide whether your neighbour owes you a notice, and both depend on depth as much as distance:
The 3-metre test. The dig comes within 3 metres horizontally of any part of your building and will go deeper than the bottom of your foundations. Distance alone isn't enough — a shallow trench 2 metres away that stays above your foundation level doesn't trigger it.
The 6-metre test. The dig comes within 6 metres of your building and is deep enough to cut an imaginary line drawn downwards at 45 degrees from the bottom of your foundations. This is the one that catches basements, piling and lift pits — serious depth, further away.
If either test is met, your neighbour must serve you a written notice at least one month before the digging starts.
How is the 3 metres actually measured?
Horizontally, and from your building — not from the boundary. That's the detail that catches people out in both directions. If your house sits right on the boundary, almost any trench next door is within 3 metres of it. If your house is set well back, a dig close to the fence may not reach you at all.
"Any part" means any part: an outrigger, a rear addition or a bay counts as much as the main wall. And depth is measured against the bottom of your foundations, which is the number neither of you usually knows — see the honest note at the end of this section.
Basements, piling and lift pits: why the 6-metre test usually applies
The 6-metre test exists for deep work, and deep work is where the real risk sits. A basement dig, piled foundations or a lift pit goes far enough down that the 45° line from your footings is easily cut even from several metres away — which is why these projects are notifiable when a shallow trench at the same distance wouldn't be.
If it's a basement next door, the basement guide covers it in full — including a right most neighbours never hear about. Treat it as the serious end of the scale. The Act's machinery is the same, but the engineering isn't: underpinning, sequencing and movement monitoring all come into play, and this is the case where having your own surveyor involved early matters most. It's also the case where a schedule of condition and security for expenses — both below — earn their keep.
The drawings they owe you
An excavation notice isn't just a letter. It must include plans and sections — drawings showing where the dig will be and how deep it will go — and it must say whether your neighbour proposes to underpin or strengthen your foundations. The government publishes the official example letter for this notice free (letter L8 in its example letters).
Your rights once a notice arrives
You have 14 days to respond, and on a section 6 notice silence counts as dissent — the dispute process starts anyway, so it never simply goes away. You can consent (the Act's protections still apply), or dissent and have a surveyor involved — your own, or one shared "agreed surveyor". Either way, your neighbour normally pays the reasonable surveyor fees — the surveyors making the award decide who pays what, and where the work is solely for your neighbour's benefit that normally means them. For deeper digs you can also ask for security for expenses — a financial safeguard put in place before work starts, so an abandoned hole next to your foundations isn't your problem to fund. Ask your surveyor before you serve that request, though: it entitles your neighbour to ask you for security in return, and missing that one-month deadline cancels your own request. The full picture, including the validity red flags, is on what your notice means.
One honest note: if you don't know how deep your own foundations are (most people don't), the safe assumption is that a nearby dig is notifiable — that's how our checker treats it, and a surveyor can confirm the depth question properly.
A schedule of condition: your evidence if cracks appear later
The single most useful thing to ask for. A schedule of condition is a dated written and photographic record of your property before the digging starts — every existing crack, every bit of movement already there.
It matters because the argument that actually happens isn't about the law, it's about attribution: is that crack new, or was it always there? Without a record it's your memory against theirs a year later. With one, it's a five-minute comparison. If you dissent, the surveyors will normally prepare one as part of the award. If you consent, there are no appointed surveyors — so nobody will do it unless you ask, and taking your own dated photos costs nothing.
Worth being straight about its status: recording one is not a requirement of the Act. The government's own guidance says exactly that, and then says it's most prudent to do it anyway. Both halves are true.
Can you ask them to underpin your foundations?
Yes — this is a real right and almost nobody knows it. Where section 6 applies, the building owner must, if you require it, underpin or otherwise strengthen or safeguard your foundations — but only so far as may be necessary. Both conditions matter: it isn't automatic, and it isn't unlimited.
Three practical notes. There's no prescribed form, wording or deadline for making the request, so put it in writing early and keep a copy. Whether the work is "necessary", and how far it goes, is a question for the surveyors rather than either owner. And on who pays, the honest answer is that the Act pulls in two directions at once — section 6 says the building owner does it at their own expense, while a separate provision says work done at the adjoining owner's request is paid for by the adjoining owner. Nothing resolves the conflict, so treat cost as something the award decides, and be wary of any page that states it confidently either way.
Security for expenses: can you ask for money to be set aside?
You can. Where you're worried about a dig being abandoned half-finished — a real risk with basements — you can serve a notice asking the building owner to provide security before work starts. It applies even though the digging is entirely on their land.
The Act deliberately says nothing about how much, what form it takes, or when it comes back; that's agreed between you or settled in the award. And there's a catch worth knowing before you ask: serving that notice entitles the building owner to ask you for security in return, and if you don't meet that within a month, your own request falls away. It doesn't affect your dissent, your right to an award, or your right to compensation for damage — but the security request itself dies. Raise it with your surveyor first.
Who actually pays for your surveyor?
Your neighbour — the one doing the digging — normally pays your reasonable surveyor's fees as well as their own. That's the Act's default, not a favour, and it's why dissenting usually costs you nothing. Who pays for a party wall surveyor covers the exceptions and what to do if a fee looks unreasonable, and the costs page has the figures if you want to know what your neighbour is letting themselves in for.
Can you actually stop the digging?
Not by refusing, no. Dissenting doesn't veto lawful excavation — it moves it into a process that controls how and when it happens, with protections written down and your property's condition recorded first. That's a better outcome than it sounds, and it's the one the Act is designed to give you. Can I refuse a party wall agreement? works through what dissent does and doesn't achieve.
No notice arrived — but the digging has started?
If the excavation clearly meets one of the tests above and nothing was ever served, your neighbour has skipped a legal duty, and you have more leverage than you might think — see my neighbour started building without a party wall notice.
Does an old notice still count? The 12-month rule
Often it doesn't, and this is worth checking before you assume you've already had your say. A party wall notice stays valid for 12 months from service. If the work hasn't begun within that year, the notice has lapsed and must be served again — which gives you a fresh response window and a fresh chance to dissent.
So if you half-remember a letter from a couple of years ago about a project that's only starting now, don't treat that as settled. Check the date on it.
Not sure which side of the 3-metre line your situation falls? Answer six questions and the free checker will tell you which rules apply — no signup, about 90 seconds.