You need to serve notice if you plan to work on a wall you share with a neighbour, build a new wall at the boundary, or dig foundations within 3 m of a neighbour's building and deeper than theirs (within 6 m in some cases). It is a legal duty under the Party Wall etc. Act 1996, separate from planning.
What is a party wall?
A party wall stands across the boundary between two properties and is shared. The wall between two semi-detached or terraced houses is the usual example. The Act also covers party fence walls, which are masonry garden walls standing astride a boundary (but not wooden fences or hedges), and party structures such as the floors between flats.
The Act applies in England and Wales. It runs alongside planning permission and Building Regulations: having those approvals doesn't remove the need to follow the Act, and following the Act doesn't replace them.
Which building work needs a party wall notice?
Typical home improvement examples are a loft conversion that puts steel beams into the party wall, a knock-through with a beam bearing on the party wall, removing a chimney breast from a shared wall, and a rear extension with foundations close to the neighbour's house. In law there are three kinds of notifiable work:
- Work to an existing party wall or structure (section 2). Examples include cutting into it to take the end of a steel beam for a loft conversion or knock-through, inserting a damp-proof course, raising or underpinning it, demolishing and rebuilding it, or cutting off a chimney breast.
- A new wall at or astride the boundary (section 1), such as the side wall of an extension built right up to the line.
- Excavation near a neighbour's building (section 6): digging within 3 m of their building or structure to a depth below the bottom of its foundations, or within 6 m where the dig would cut a line drawn down at 45 degrees from the bottom of their foundations.
- Not usually notifiable: minor jobs such as drilling to fix shelves or kitchen units, adding recessed sockets or replastering. The test is whether the work could affect the wall's strength or damage your neighbour's side.
How much notice do I have to give?
The Act sets minimum notice periods. A notice lapses if the work hasn't started within a year, so don't serve it too early. There is no official form. The notice should give the names and addresses of all owners, the address of the property, a full description of the work and the proposed start date, and it should state clearly that it is a notice under the Party Wall etc. Act 1996. You can hand it over, post it, or email it if your neighbour has agreed to that. A surveyor can serve it for you with your written authority. The minimum periods are:
- Party structure notice, for work to an existing party wall: at least two months before work starts.
- Line of junction notice, for a new wall at the boundary: at least one month.
- Notice of adjacent excavation: at least one month, with plans and sections showing where and how deep you will dig.
What can my neighbour do when they receive a notice?
Every adjoining owner, including joint owners and any leaseholder whose lease is for more than a year, should reply in writing within 14 days. They can consent or dissent.
If they consent, you can start once the notice period ends. It is still sensible to agree a record of the condition of their side, with dated photographs, before work starts. If they dissent, or don't reply within 14 days to a party structure or excavation notice, a dispute is treated as having arisen and surveyors are appointed. For a new boundary wall, silence means you can only build wholly on your own land, at your own expense.
What is a party wall award, and who pays for the surveyors?
Once there is a dispute, the owners either agree on one 'agreed surveyor' who acts impartially for both, or each appoints their own. If those two can't agree, they select a third. The surveyors produce a party wall award: a legal document setting out what work will be done, how and when, usually with a schedule of condition of the neighbour's property. Awards commonly also deal with access for the surveyors to check the work, and with how any damage will be made good.
The building owner, meaning the person having the work done, normally pays the surveyors' fees. Costs can be shared where work is needed because of a defect in the wall. As a typical guide for 2026 outside London, an agreed-surveyor award often costs around £900–£1,800, and two surveyors £1,800–£3,500 in total. Fees rise with each neighbour involved and with the complexity of the job.
What happens if I start work without serving notice?
Failing to serve notice isn't a criminal offence, and the Act has no enforcement procedure of its own. Your neighbour can, however, go to court for an injunction to stop the work or seek other legal redress. That can hold up a job for far longer than the notice period would have, and without a record of condition, any later argument about damage is harder to settle. If you realise part-way through that notice was needed, pause that part of the work and take advice before going further.
The Act also gives you rights. With 14 days' notice, your neighbour must allow access to their property where it is needed to carry out the notified work, and obstructing someone who is entitled to enter is an offence.
How do I make the party wall process go smoothly?
Most party wall disputes come from surprise rather than from the work itself. This guide summarises the government's explanatory booklet. Only a court can give a definitive interpretation of the Act, so speak to a party wall surveyor if your situation is unusual. In most cases these steps help:
- Talk to your neighbours before the notice arrives. A friendly explanation and a copy of the drawings often leads to consent.
- Serve notice as soon as your drawings are final. Two months can easily delay a start date.
- Describe the work accurately. Vague notices cause disputes.
- Take dated photographs of any existing cracks on both sides, whether or not surveyors are appointed.
- Ask your builder to plan the order of work around the notice periods.
Sources
- GOV.UK – The Party Wall etc. Act 1996: explanatory booklet
- GOV.UK – Party walls and building work
- legislation.gov.uk – Party Wall etc. Act 1996, section 6 (adjacent excavation)
- legislation.gov.uk – Party Wall etc. Act 1996, section 3 (party structure notices)
This guide is general information for homes in England, not legal or professional advice for your property. Rules change — check with your council or the Planning Portal before you rely on it.