Party wall rules explained (England and Wales)

What counts as a party wall?

A party wall is a wall shared by two properties — the wall between semi-detached or terraced houses, or a wall that sits astride the boundary. The Act also covers party fence walls (garden walls astride the boundary, not part of a building) and party structures such as floors between flats.

When does the Act apply?

There are three main kinds of work:

• Building a new wall on or at the boundary (section 1).
• Work to an existing party wall — for example cutting in to take steel beams, raising its height, thickening it, underpinning it, or cutting away chimney breasts (sections 2 and 3).
• Excavating near a neighbour's building: within 3 m where you dig deeper than their foundations, or within 6 m where you would cut a 45° line drawn down from the bottom of their foundations (section 6).

Serving notice

Notice must be in writing and given to every owner of the neighbouring property: at least two months before work on a party wall (a party structure notice), and at least one month before building a new boundary wall or excavating.

The notice describes the work and when it is planned to start. A notice of adjacent excavation must come with plans and sections showing the site and the depth of the foundations. A notice lapses if the work does not start within 12 months.

• Create the notice with our free generator: party wall notice

Your neighbour's reply: 14 days

Your neighbour can consent in writing, or dissent. If they dissent, or do not reply within 14 days, a dispute is treated as having arisen — that is a normal step, not a failure, and it is resolved by surveyors.

Surveyors and the party wall award

Both owners can agree on one surveyor (an agreed surveyor), or each appoint their own, in which case the two surveyors select a third surveyor in case they cannot agree.

The surveyors make an award: a document that sets out what work can be done, how and when, and usually records the condition of the neighbour's property beforehand (a schedule of condition). The building owner normally pays the surveyors' reasonable fees.

Access to next door

Section 8 gives the building owner a right to access the neighbouring land where it is necessary to carry out work under the Act, after giving 14 days' notice (except in an emergency).

Mistakes that cause disputes

• Starting work before serving notice or before an award is in place.
• Assuming planning permission or Building Regulations approval covers party wall matters — it does not; they are separate.
• Skipping the schedule of condition, so nobody can prove what damage was already there.
• Letting a notice lapse by not starting within 12 months.

When you usually don't need notice

Minor work such as plastering, adding or replacing electrical sockets, or drilling to fix shelves or cupboards normally does not need notice. If in doubt, ask — or speak to a party wall surveyor.