The Party Wall Act explained

Most people meet the Party Wall Act at exactly the wrong moment. The drawings are approved, the builder is booked for the fifteenth, the skip's ordered, and then somebody mentions in passing that you should probably have served notice on next door about two months ago.

It's a perfectly manageable bit of law once you know it applies to you, and it exists for an entirely sensible reason, which is that building work on a shared boundary affects somebody else's property as much as your own and they're entitled to know about it. The trouble is that a great many people don't find out it applies until it's much too late to be convenient, and a project that was ready to go sits still for weeks while notices run their course. If you're at the beginning of a project rather than the end of one, it's worth reading this alongside how planning applications work, because the two processes can and should run at the same time.

The obvious one is the wall between two semi detached houses, or between two houses in a terrace, meaning a wall that stands on the land of two different owners and serves both of them.

But the Act reaches a good deal wider than that. It also covers a garden wall built astride the boundary line, the floors and ceilings between flats, building an entirely new wall right up on the boundary, and excavating near your neighbour's building in cases where you never lay a finger on any part of their property at all.

That last category is the one nobody expects, and it's the one that quietly brings ordinary domestic extensions inside the Act when the owner had no idea it had anything to do with them.

Three situations are set out in the Act, and if what you're doing falls into any one of them then you've got a legal duty to notify your neighbour in writing before you start.

The first is work to an existing party structure, which means cutting into it to take a beam or a joist, raising it, underpinning it, taking a chimney breast off it, inserting a damp proof course through it, or knocking it down and rebuilding it. Two months notice for any of that.

The second is building on the line of junction, meaning putting up a new wall either on the boundary itself or right up against it. One month.

The third is excavating near your neighbour's building. If you're digging within three metres of their building and going deeper than the bottom of their foundations, that's covered. And if you're within six metres and going deep enough that a line drawn downwards at forty five degrees from the bottom of their foundation would pass through your excavation, that's covered too. One month notice for both.

The three metre rule catches ordinary extensions all the time. A standard foundation alongside a semi detached house is very often within three metres of next door and dug deeper than their footings, and you're nowhere near touching their wall or even their garden. People are genuinely taken aback when we tell them, and then slightly annoyed that nobody mentioned it earlier, which is fair enough.

Failing to serve notice isn't a criminal offence, but it leaves you badly exposed and we'd never advise it.

Your neighbour can apply to the court for an injunction stopping the work, and courts do grant them. A half dug trench, a stop order, and a builder standing about with nothing to do while his next project waits is roughly as bad as a domestic building project gets, and it will cost you a great deal more than doing the thing properly would have.

The bigger practical problem is what happens if something cracks. Part of the proper process is a schedule of condition, which is a written and photographed record of the state of your neighbour's property before any work starts. Without one, every crack in their house becomes your problem to disprove, and disproving a crack after the event is far harder than photographing it beforehand. Older properties round here have plenty of existing cracks and historic settlement, and a schedule of condition is what stops you being handed the bill for all of it.

We've seen people spend more money arguing about a crack that was demonstrably there before they started than the entire notice process would have cost them in the first place.

They've got three options and fourteen days to respond.

They can consent in writing, and that's the end of the matter, so keep the letter somewhere safe and get on with the project. That's by far the most common outcome where the relationship is reasonable and the notice wasn't a surprise.

They can dissent but agree to appoint a single surveyor between the two of you, known as an agreed surveyor, who acts impartially for both parties rather than representing either of you.

Or they can dissent and appoint their own surveyor, in which case there are two of them, and those two jointly select a third surveyor right at the outset to settle anything they can't agree between themselves.

And if your neighbour doesn't reply at all within the fourteen days, that counts as deemed dissent. It does not count as permission, which is the other thing people routinely get wrong, assuming silence means everything's fine and they can crack on regardless.

Worth knowing too that you, as the building owner, normally pay the surveyors' fees, because you're the one getting the benefit of the work. It isn't always the case and it can be apportioned differently where the work genuinely benefits both properties, but that's the usual position and it's worth having in the budget rather than discovering it later.

Where surveyors are appointed they produce an award, which is a formal legal document setting out precisely what work may be carried out, how it's to be done, what hours it can happen in, who pays for what, and recording the condition of your neighbour's property before anything starts.

It protects both of you, which is worth remembering if by this point the whole business is starting to feel like your neighbour being difficult for the sake of it. The award tells you exactly what you're permitted to do, which means nobody can move the goalposts once you've started, and it tells them exactly what to expect and where they stand if there's damage. Once an award is in place, arguments about the work very largely stop, because all the answers are written down and neither of you has to remember what was agreed.

Either party can appeal an award to the county court, but only within fourteen days of it being served, and in practice appeals are uncommon.

Please do this. It's the most useful thing in this article and it costs you nothing at all.

A formal notice arriving on the mat with no warning turns neighbours who would have happily consented into neighbours who dissent, because to somebody who's never seen one before it reads like the opening move in legal proceedings. And once somebody has appointed a surveyor out of alarm, you're into a process with fees attached that a five minute conversation would have avoided entirely.

So go round. Tell them what you're planning and roughly when you're hoping to do it, show them the drawings so they can see what it actually looks like rather than imagining the worst, and explain that you'll be serving a formal notice because the law requires it and not because anything has gone wrong. Most of the time that's the whole thing dealt with, they consent in writing a fortnight later, and neither of you appoints anybody at all. We've had projects where the neighbours ended up more enthusiastic about the extension than the client was, purely because somebody bothered to knock on the door first.

Where it does go the other way, it's usually because there was already history between the two properties long before you turned up with an extension. And in that case the formal process is genuinely your friend rather than an obstacle, because it takes the argument out of your hands entirely and puts it in front of somebody impartial who's dealt with a hundred of them.

Exactly the same Act, the same notice periods, the same process. Industrial and commercial projects on tight sites hit the excavation provisions regularly, because there's rarely three metres of spare ground going begging on a developed industrial estate, and we do a great deal of that sort of work so it's very familiar ground.

Early, ideally at the same time as your planning application, so the notice periods run alongside everything else rather than starting after it and adding two months to the end.

Two months is a long time to discover you need when the builder is turning up on Monday, and we'd far rather have that conversation with you at the survey stage than have you ring us in a panic in six weeks' time.

We prepare the notices and the drawings that go with them, so your neighbour can actually see what's proposed rather than trying to picture an extension from a description in a letter. Vague notices are the ones that get dissented, every single time, and a clear drawing does more to get you a consent than any amount of carefully worded explanation.

And if you're not certain whether the Act even applies to what you're planning, just ask. It's usually a two minute answer on the phone and it's a great deal better knowing now, and there's more on what we do on the Party Wall Act page.

For more information please call us on 07773 899 597 or contact us through this website.