Party Wall Agreement Explained: What the Act Covers, How Notice Works and What an Award Is

Quick answer

A party wall agreement is the written arrangement between you and a neighbour that lets you carry out work covered by the Party Wall etc. Act 1996: building a new wall on the boundary, altering a wall you share, or excavating close to their foundations. It is not planning permission and it is not building control. It exists to protect the neighbour's property and to fix in advance who pays if something goes wrong. In practice it takes one of two forms: the neighbour consents in writing to your notice, or surveyors draw up a document called an award. The Act applies in England and Wales only.

What is a party wall?

The Act uses the phrase more widely than everyday speech does. It covers three things.

• A party wall stands on the land of two owners and forms part of both buildings, or stands wholly on one owner's land but separates two buildings. The wall between two terraced houses is the obvious case. A wall that is on the boundary but only has a garden on the other side is not a party wall, unless the neighbour has built against it.
• A party fence wall stands astride the boundary but is not part of a building. A brick garden wall shared by two houses is one; a timber fence is not.
• A party structure is the wider term and includes floors and ceilings that separate flats, so the Act reaches into conversions and maisonettes as well as houses.

The distinction matters because the Act attaches different rights and different notice periods to each. Most disputes about whether a wall is a party wall come down to whether the neighbour's building actually uses it, not to where the boundary line runs.

What the Party Wall etc. Act 1996 does

The Party Wall Act, to give it its everyday name, does two things at once. It gives you rights you would not otherwise have, such as the right to cut into a shared wall to insert a beam, or to build a new wall astride the boundary. And it imposes a procedure for exercising those rights: notice to the neighbour, a set period for them to respond, and a mechanism for settling disagreement without going to court.

Three things it does not do are worth stating plainly, because they are the source of most confusion.

• It does not give the neighbour a veto. They cannot stop work that the Act permits. What they can do is insist on the procedure, which in practice means surveyors and an award.
• It does not replace planning permission or building regulations approval. Those are separate consents from the local authority. A project can need all three.
• It does not decide where the boundary is. If the position of the boundary is itself in dispute, that is a separate legal question the party wall process cannot resolve.

The three kinds of work the Act covers

Whether you need to serve notice depends on the work, not on the wall. The Party Wall Act names three situations, each in its own section, and each with its own notice period.

Section 1: building a new wall on the line of junction

You want to build a new wall on the boundary where there is none, or astride it. This is the section that catches a side return extension or a new garden wall. If you build wholly on your own land, up against the boundary, you still have to give notice, and the neighbour then has a say in whether the wall becomes a shared one. Notice period: one month.

Section 2: work to an existing party structure

You want to do something to a wall or floor you already share. Cutting a pocket for a steel beam, raising the wall for a loft conversion, underpinning it, removing a chimney breast, thickening or rebuilding it, or cutting away projections. This is the section most loft conversions and many rear extensions fall under. Notice period: two months.

Section 6: excavating near a neighbour's building

You want to dig foundations or a basement close to a neighbouring building. Two tests apply, and either one triggers the section.

• The three metre test. You are excavating within three metres of the neighbour's building and to a depth lower than the bottom of their foundations.
• The six metre test. You are excavating within six metres of the neighbour's building and your excavation would cut a line drawn downwards at 45 degrees from the bottom of their foundations.

The six metre test is the one people miss. A basement can trigger it against a house that is not even attached to yours. Notice period: one month, and the notice must include plans and sections showing the depth and location of the proposed excavation.

One project often triggers more than one section. A rear extension on a terrace can need a section 1 notice for the new flank wall, a section 2 notice for the beam that goes into the party wall, and a section 6 notice for the foundations. Each is served separately, and where you have neighbours on both sides, each neighbour gets their own.

When do you need a party wall agreement?

You need to serve notice whenever your work falls into one of the three sections above. The agreement follows from the notice: it is either the neighbour's written consent, or an award if they do not consent.

Two things do not trigger the Act, and people sometimes serve notice unnecessarily for them. Minor work to your own side of a party wall, such as plastering, fixing shelves or running cables in chases, is outside the Act. So is work that is entirely on your own land and does not go below the neighbour's foundations or within the distances in section 6. A single storey extension with shallow strip foundations well inside your plot often needs no notice at all.

Where the work is borderline, serve. A notice costs little, an injunction costs a great deal, and a neighbour who was consulted rarely becomes a neighbour who objects.

The party wall notice: what it must say and when

There is no prescribed form, but the notice must contain certain things or it is invalid, and an invalid notice does not start the clock.

• Your name and address as the building owner, and the name of every owner of the neighbouring property. Where the neighbour's house is let, both the freeholder and any tenant with a lease of more than a year are owners for the purposes of the Act, and each must be served.
• The address of the building where the work will be done.
• A description of the proposed work, specific enough for the neighbour to understand what is being done to the wall or ground. For section 6, drawings showing the depth and position of the excavation are compulsory.
• The date on which you intend to start, which must be no earlier than the end of the notice period.
• The date of the notice, and a statement that it is served under the relevant section of the Act.

The notice is valid for twelve months. If work has not begun within a year of serving, you have to serve again. Serve it by hand or by post to the neighbour's address; if the owner does not live there, address it to the owner of the property. A notice served on a tenant who is not an owner has not been served.

After the notice: consent, dissent, and silence

The neighbour has fourteen days to respond in writing. Three things can happen.

1. They consent in writing. That consent is your agreement. No surveyor is needed. It is still sensible to record the condition of their property before you start, because if damage occurs later you will want a baseline.
2. They dissent. A dispute is deemed to exist, and the Act's resolution mechanism in section 10 begins. Both sides appoint a surveyor, or agree on a single one.
3. They do nothing. Silence for fourteen days is treated as dissent. This surprises people on both sides. A neighbour who ignores the letter has not avoided the process; they have started it.

Dissent is not obstruction. Many neighbours dissent on advice precisely because it brings a surveyor in to protect their interests, and the building owner pays the surveyor's fees. Treat it as procedure, not hostility.

The party wall award

Where there is dissent, the surveyors produce an award. It is the document most people mean when they say party wall agreement. It sets out what work may be done, how and when it may be done, what protection the neighbour's property will have, and how any damage will be made good. It normally includes a schedule of condition: a written and photographic record of the neighbour's property before work starts, which is the evidence both sides rely on afterwards.

Either owner may appeal an award to the county court within fourteen days of receiving it. After that it is binding. An award is specific to the work described in it; if the design changes materially, the surveyors have to address the change, and a new notice may be needed.

Two surveyors, one for each side, or one agreed surveyor acting for both: both routes are lawful. An agreed surveyor is quicker and cheaper and works well between neighbours on good terms. Where relations are already poor, separate surveyors give each side someone who is unambiguously theirs. In either arrangement the surveyors select a third surveyor at the outset, who is only called in if the two cannot agree.

Party wall disputes and how they are settled

The Party Wall Act channels disputes into the surveyors rather than the courts. The surveyors are not advocates: their duty is to the Act, and their job is to produce a fair award, not to win for the person who appointed them. Most disputes are about method and protection rather than whether the work may happen at all, because the Act has already settled that question in the building owner's favour.

Where the surveyors cannot agree, the third surveyor decides, and either party may refer a point to the third surveyor directly. Where damage occurs, the award or a later addendum determines making good, and the building owner is liable for damage caused by the work whether or not it was foreseen.

What if the work starts without an agreement?

The Act gives no criminal penalty for ignoring it. What it gives the neighbour is the civil remedy of an injunction: an order from the court stopping the work until the Act has been complied with. Injunctions are granted readily in party wall cases because the failure to serve is usually beyond argument. The work then stops, the process starts from the beginning, and the building owner has usually paid for both the delay and the legal costs.

There is a second consequence that outlasts the project. Without an award and a schedule of condition, any later claim about damage has no agreed baseline. A crack the neighbour says appeared during your works is your word against theirs, and the absence of the process you should have followed does not help your side of the argument.

If you are the neighbour and work has started next door without notice, the position and your options are covered in our guide on receiving a party wall notice, which deals with the adjoining owner's side.

Party wall notice templates

Because the Act prescribes content but not form, a template is a safe way to make sure nothing required is missed. The government's explanatory booklet on the Act contains example letters for each section, and those are the safest starting point because they track the statutory wording. We keep a party structure notice template with a consent reply for section 2 work, which is the form most loft and extension projects need.

Whatever template you use, check three things before sending it: that it names the right section, that the neighbour's name is the owner's and not a tenant's, and that the start date is after the notice period ends.

Party wall by type of project

The Act is the same for every project, but which sections apply and how many neighbours are involved depends on what you are building.

• Loft conversions almost always involve section 2, because the floor steels bear onto the party wall and the wall is often raised. Our loft conversion party wall guide covers that case in detail, including the timeline against the build.
• Rear and side extensions commonly trigger section 1 for the new flank wall and section 6 for the foundations. A side return extension on a terrace is the classic case of notices to both sides.
• Basements are the heaviest use of section 6, because the excavation is deep and the six metre test can reach houses that are not attached. Our guide to building a basement under a house deals with the neighbour and excavation questions.
• Chimney breast removal is section 2 even where nothing else in the house changes, because the breast is part of the party wall.

Frequently asked questions

What is a party wall agreement?

It is the arrangement under the Party Wall etc. Act 1996 that allows you to do work to a shared wall, build on the boundary, or excavate near a neighbour's building. It takes the form of either the neighbour's written consent to your notice, or an award drawn up by surveyors if they dissent. It is separate from planning permission and building regulations.

What is the Party Wall Act 1996?

An Act of Parliament, in force since 1997, that applies in England and Wales. It gives building owners rights to carry out certain work affecting neighbours, and sets out the notice and dispute procedure that must be followed to exercise those rights. It covers three situations: new walls on the boundary, work to existing shared structures, and excavation near neighbouring buildings.

How long does a party wall notice last?

Twelve months. If the work has not started within a year of serving the notice, the notice lapses and you must serve again. The notice periods before work can begin are one month for section 1 and section 6 work and two months for section 2 work.

What is the party wall 3 metre rule?

It is one of the two tests in section 6 of the Act. If you excavate within three metres of a neighbouring building and to a depth below the bottom of their foundations, you must serve notice. The companion six metre test applies where the excavation is within six metres and would cut a 45 degree line drawn down from the base of their foundations.

Can my neighbour refuse a party wall agreement?

They can dissent, but dissent does not stop the work. It triggers the appointment of surveyors, who produce an award setting out how the work will be done and how the neighbour's property will be protected. The Act does not give the neighbour a veto over work it permits.

What happens if you do not have a party wall agreement?

The neighbour can apply for an injunction stopping the work until the Act is complied with, and courts grant these readily. You also lose the schedule of condition, which means any later claim about damage has no agreed baseline. Serving notice properly is far cheaper than either outcome.

Working with houseUP

houseUP is a London design and build contractor. On any project that touches a neighbour's property we identify which sections of the Act apply at design stage, draft and serve the notices with the correct periods, and plan the programme around the response window rather than discovering it on site. Where an award is needed we work with the appointed surveyors on method and protection so that the award reflects how the job will actually be built.

If you are unsure whether your project needs notice, send us the address and a description of the work. That is usually enough to tell you which sections, if any, are engaged.

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