The Party Wall Act for a chimney, a garden wall and an extension
A neighbour cannot veto your building work. Here is what a notice actually does, which of the three periods you are under, and why silence counts as dissent.
A neighbour cannot veto work under the Party Wall etc. Act 1996. If they dissent, or ignore the notice completely, the Act deems a dispute and hands it to surveyors, whose award sets the terms and lets the work go ahead. Serving a notice buys you a delay, not a refusal.
The short version
- Silence is dissent, and dissent is not refusal. Both routes end in a surveyors' award that says how and when the work is done, not whether it happens.
- Taking a chimney breast off a party wall needs two months' notice. It is the trigger homeowners miss most often, because it feels like an internal job.
- Excavating near a neighbour's foundations needs one month, and building a new wall on the boundary line needs one month. Only work to an existing party structure needs two.
- A masonry garden wall astride the boundary is a party fence wall. A wooden fence is not, and neither is a wall standing wholly on your own land.
- None of this is planning permission or building control. An award does not give you permission, and permission does not excuse you from serving a notice.
No veto
Dissent is not refusal, and silence is dissent
Your neighbour has no power to stop the work. That fact is missing from most of the pages you will find, because most of them are written by firms whose business is being appointed as a surveyor.
The machinery runs like this. Once a notice is served, the adjoining owner has fourteen days beginning with the day of service to serve a notice back saying they consent. If they do not, section 5 deems them to have dissented and deems a dispute to have arisen, and section 6(7) says the same for excavation notices. Doing nothing produces the same legal result as objecting.
A deemed dispute is not a dead end. It triggers section 10, which resolves disputes by surveyors: either one agreed surveyor appointed by both of you, or one each with a third selected by those two. Their award can determine the right to carry out the work, the time and manner of carrying it out, and any other matter arising, including who pays the cost of making the award. The award is conclusive, and can only be challenged by an appeal to the county court within fourteen days beginning with the day it is served.
Note the wording. The award determines the right to execute the work. A neighbour who dissents has bought a say in the hours, the schedule of condition and the making good. They have not bought a veto, because the Act never gave them one.
None of that is an argument against surveyors. Where the dispute is real, section 10 settles it faster and more cheaply than a court would, and a good surveyor protects both sides. The criticism is of pages implying that a notice is always needed and that a neighbour saying no ends the project.
The commonest missed trigger
Taking out a chimney breast is notifiable work
If the chimney breast you want gone sits in the wall you share with next door, that is work to a party structure and it needs a notice. People miss it because a breast removal feels like an internal job: a skip, a few days, a plasterer, done.
The Act does not see it that way. Section 2 lists the rights a building owner has over a party structure, and two of them cover this: cutting into a party structure for any purpose, and cutting away from a party wall any projecting chimney breast, jamb or flue. In a terrace or a semi the stack usually sits in the party wall itself, and the breast is a lump of that shared wall projecting into your room. So section 3 requires a party structure notice at least two months before the work begins: two months from the first day on the job, not from the day you decide.
There is a structural reason to take it seriously too. Your neighbour's flues often run in the same stack, and section 2 makes the right conditional on making good all damage next door and on carrying up any of their flues and chimney stacks that form part of, or rest against, that structure. Strip the breast out on two floors, leave the stack in the loft standing on nothing, and the problem is yours to fix.
Rule damp out first. Plenty of breasts come out to cure something a pot lid and a vent would have cured, so read what a damp patch on a chimney breast is telling you. If the answer is the stack, that is brickwork and repointing, not demolition.
Three notices, three periods
Which notice you are under, and how long it runs
Most pages give one notice period, usually two months, and apply it to everything. There are three, they attach to different sections, and picking the wrong one costs you weeks.
| The work | Section | Notice before work starts | If they do not reply |
|---|---|---|---|
| Cutting into, repairing, raising or demolishing an existing party wall or party structure, chimney breast included | 2 and 3 | At least two months | Deemed dissent after fourteen days. Surveyors set the terms, the work proceeds |
| Building a new wall on, or up to, a boundary line with nothing built on it now | 1 | At least one month | Without consent you may still build, but wholly on your own land and at your own expense |
| Excavating near a neighbour's building or structure, usually for extension foundations | 6 | At least one month | Deemed dissent after fourteen days. Surveyors set the terms, the work proceeds |
The middle row is the one place where a neighbour not consenting genuinely changes the outcome. Section 1 gives one month for building on the line of junction. Consent within fourteen days and the wall goes half on each side, with the cost shared according to the use each of you makes of it. No consent and you have not lost the wall, only the right to put it on their land: it goes up wholly on your side, at your expense.
A party structure notice has to state your name and address, the nature and particulars of the work, with plans where special foundations are proposed, and the date work will begin. It does not last forever. It ceases to have effect if the work has not begun within twelve months of service and is not pursued with due diligence, and a section 6 notice carries the same limit.
Extensions
The three metre rule and the six metre rule
Digging foundations for a rear extension near a neighbour's house, garage or outbuilding usually means a month's notice under section 6. There are two triggers, and the second catches people who have correctly checked the first.
Within three metres, and deeper
Excavation within three metres measured horizontally from any part of the neighbour's building or structure, where any part of your dig goes to a lower level than the bottom of their foundations. Measured horizontally is the phrase that matters: it is a plan measurement, not a distance paced out down a sloping garden.
Within six metres, and under the forty-five degree line
This one reaches further. It applies within six metres measured horizontally where any part of your excavation would meet a plane drawn downwards at forty-five degrees to the horizontal from the bottom of the neighbour's foundations. Draw that line sloping down and away from the underside of their footing, and if your dig cuts through it you are caught at five metres out. Deep pads, piles, a basement or a lift pit are what reach it. A shallow strip footing does not.
The notice must say whether you propose to underpin or otherwise strengthen their foundations, with plans and sections showing the site and depth of the dig. The duty runs the other way too: the adjoining owner can require you to underpin or safeguard their foundations so far as necessary, at your expense. That is a real cost, and it is the argument for putting the excavation drawings in front of them early.
Garden walls
A shared wall is only a party wall if it is masonry on the line
A party fence wall is a masonry wall standing astride the boundary that does not form part of a building. The ordinary wall between two back gardens, built on the line, is the classic example, and work to it is notifiable like work to a party wall.
Two things it is not. A wooden fence is not a party fence wall, so replacing panels or posts is not party wall work whatever anyone tells you. And a wall standing wholly on your own land is not a party wall however long your neighbour has leaned a compost bin against it. Ownership follows where the wall stands, and even footings projecting into their ground do not change that.
So look at where the wall actually sits before you serve anything. Straddling the line, you are in the Act. Inside your boundary, the Act has nothing to say and your real questions are height, sightlines and whether you need permission at all.
Where a shared wall does need attention, be careful what counts as repair. Section 2 lists making good, repairing, or demolishing and rebuilding a party fence wall where a defect makes that necessary, as well as raising and reducing one. It is also the moment to get the mortar specification right: an old soft-brick wall rebuilt in a hard cement mix spalls on both sides of the boundary.
What it is not
Not planning permission, not building control, England and Wales only
The Party Wall etc. Act is a private statutory code between two owners. The council does not administer it, there is no register of notices, no officer checks whether you served one and there is no fee to the local authority. Gov.uk puts it plainly: party wall agreements are different from planning permission and from building regulations approval.
The three regimes run separately and in parallel. An award does not give you planning permission, permission does not discharge your duty to serve a notice, and building control signing off your foundations says nothing about whether the neighbour was told. If the difference is not clear, start with planning permission, building regulations and listed building consent, then how the building control route gets chosen.
The Act applies in England and Wales only. Scotland has the common law of common gables and the Tenements (Scotland) Act 2004 instead, and the Act does not reach Northern Ireland. So a relative in Glasgow who never served a notice for their chimney breast is right, and irrelevant to you.
Before the first brick comes out. If notifiable work starts without a notice, the section 10 surveyors have no jurisdiction, because their appointment depends on one having been served. The neighbour's route is then the court, and an injunction stopping a half-demolished chimney breast is worse than a two month wait. This page explains the Act in general and is not legal advice.
What to do next
Working out whether you need to serve, and on whom
Whether you need to serve a party wall notice depends on the structure, the section it falls under and who the owners are, so work those out before you fix a start date, then ask for written consent. Take it in order.
- Identify the structure, not the job. Is the thing you are cutting into, digging beside or building on shared? A chimney breast in a party wall is. A stud wall inside your own house is not. A wooden fence is not.
- Match it to a section and count backwards. Existing party structure, two months. New wall on the boundary line, one month. Excavation near their foundations, one month. Count back from the day work starts.
- Work out who the owners are. The Act's definition is wider than the person you wave at: it takes in anyone entitled to receive the rents, so a converted house can have a freeholder and a long leaseholder who both need serving.
- Ask for written consent first. Consent inside the fourteen days means no dispute, no surveyor and no award. Most neighbours consent when they are told early and in person. The ones who dissent tend to be the ones who found out from the scaffolders.
- Photograph their side before you start. A dated record of the cracks already in their plaster is what settles the argument afterwards.
- If they dissent or go quiet, propose one agreed surveyor. One appointment instead of three is quicker and costs less, and the award allocates those costs between you.
If the job in front of you is the brickwork rather than the paperwork, chimney breast support, a rebuilt shared garden wall, making good after an extension, that is our side of it. Have a look at bricklaying and repointing, or ask for a look at it and Thomas will tell you what the wall actually is. He will also tell you when you do not need us at all.
Questions
Common questions
Do I need a party wall notice to remove a chimney breast?
If the breast is part of the wall you share with next door, yes. Cutting into a party structure and cutting away a projecting chimney breast are both rights listed in section 2 of the Party Wall etc. Act 1996, so section 3 requires a party structure notice at least two months before the work begins.
What happens if my neighbour ignores the party wall notice?
Nothing stops. If they do not serve a notice of consent within fourteen days of service, the Act deems them to have dissented and deems a dispute to have arisen. That triggers the surveyor mechanism in section 10, and the resulting award sets the terms on which the work goes ahead.
Can my neighbour refuse permission for my extension?
Not under this Act. A dissenting neighbour gets a say in the time and manner of the work through the surveyors' award, not a veto over whether it happens. The one exception is a new wall on the boundary line: without their consent you can still build it, but wholly on your own land and at your own expense.
Does the Party Wall Act apply to a wooden fence?
No, a party fence wall is a masonry wall standing astride the boundary that does not form part of a building. Gov.uk says wooden fences are excluded, so replacing panels or posts is not party wall work and no notice is needed.
How long does a party wall notice last?
A party structure notice ceases to have effect if the work has not begun within twelve months of the day it was served and is not being pursued with due diligence. An excavation notice under section 6 carries the same twelve month limit, so a notice served far too early has to be served again.
Read next
Related advice
The guides below pick up where this one leaves off, and the bricklaying and repointing page covers the work itself and the places we cover, if you would rather have the job looked at.
- Garden wall planning permission and the height rules
- Planning permission, building regulations and listed building consent: which one you actually need
- Building notice, full plans or a competent person scheme
- Listed building consent for repointing and rendering
Bricklaying and repointing, and where we cover All advice articles
Who wrote this
Thomas Hannen
Thomas owns Bournemouth Roofing & Building and prices every job himself instead of sending somebody else. The company is Bournemouth Roofing & Building Ltd, number 15471719, registered in England and Wales. If you want to talk something through before you commit to anything, the site visit and the written itemised quote are both free.
Free quote
Not sure whether that wall is shared?
Thomas comes out himself, looks at where the wall actually sits and what it is made of, and puts in writing what the work involves. The site visit and the written itemised quote are both free.