Party walls and extensions: what Wiltshire homeowners need to know

If you live in a semi-detached or terraced house, or you are building close to the boundary, the Party Wall etc. Act 1996 is likely to apply. It is separate from planning permission and building regulations, and it is your responsibility as the homeowner, not the builder's.

When does the Act apply?

There are three main situations:

• Work to an existing party wall. For example cutting in a steel beam, inserting a damp-proof course, or raising or rebuilding a shared wall.
• Building a new wall on the boundary line. Such as the side wall of an extension, or a new garden wall built astride the boundary.
• Digging near a neighbour's building. Excavating within 3 metres of their building and deeper than its foundations, or within 6 metres where the dig would cut a line drawn down at 45 degrees from the bottom of their foundations.

Extension foundations often fall into the third category, so it is worth checking early.

Serving notice

You must give your neighbour written notice before the work starts: usually two months for work to a party wall, and one month for new boundary walls or nearby excavation. The government publishes an explanatory booklet and guidance with the details.

Your neighbour can agree in writing, or dissent. If they dissent, or do not reply within 14 days, a party wall surveyor (or one for each side) prepares an award setting out how the work will be done.

Keeping it simple

• Talk to your neighbours before the notice lands on their doormat.
• Serve notice early so it does not hold up your start date.
• Take dated photos of their side of the wall before work begins.
• Make sure your builder knows about any award and works to it.

Does it apply to fences?

A timber fence on your own land does not usually involve the Act. A new masonry wall on the boundary line can. Our boundary walls page explains how we build them.

This guide is general information, not legal advice. For anything complex, speak to a party wall surveyor.