When does the Party Wall Act apply to an extension?
In England and Wales the Party Wall etc. Act 1996 applies when an extension involves work to a shared wall, a new wall on the boundary, or excavating near a neighbour's foundations. You must serve notice before starting: two months for party wall work and one month for new boundary walls and excavations. Scotland and Northern Ireland have no equivalent Act.
Which extension work triggers the Act?
- Cutting into a party wall to insert a beam or flashing.
- Raising or thickening a party wall, common on side returns.
- Building a new wall astride or up against the boundary line.
- Digging foundations within 3 m of a neighbour's building and deeper than its foundations, or within 6 m in some cases.
How the notice process works
You serve a notice describing the work. Your neighbour has 14 days to consent or dissent. If they consent, work can start after the notice period. If they dissent or do not reply, a dispute is deemed to exist and surveyors prepare a party wall award setting out how the work will be done and how the neighbour's property will be protected.
Who pays for the surveyors?
Usually the person doing the work, which means you pay for your surveyor and, if appointed, your neighbour's. Agreeing one surveyor for both sides keeps the cost down.
How to keep it simple
Talk to your neighbours early, show them the drawings and explain the timetable. A friendly conversation before the formal notice arrives makes consent far more likely. We tell you which notices your design needs and when to serve them.
Scotland and Northern Ireland
There is no Party Wall Act in Scotland or Northern Ireland. Where work affects a shared wall or a neighbour's land, access and protection are agreed with the neighbour, ideally in writing, and the general law of neighbouring property applies.
This guide is general information, not legal or professional advice for your property. Rules can change; we check the current position for your address at the survey.