Whether a Party Wall Agreement is required will depend on how your extension interacts with shared walls, boundary lines, and neighbouring foundations.
When a Party Wall Agreement is Required
Under the Party Wall etc. Act 1996, you must serve a Party Wall Notice and obtain an Agreement if your rear extension involves:
- Using a shared wall – for example, cutting into it to insert a steel beam.
- Cutting away from a shared wall – such as removing a chimney breast or buttress.
- Constructing a new wall on or astride the boundary line (the “line of junction”).
📅 For these types of works, you are required to give at least two months’ notice before commencing.
Excavations Near a Neighbour’s Property
The Act also applies to certain excavation works, even if they take place entirely on your land. You must serve notice and secure an Agreement if you plan to excavate:
- Within 3 metres of a neighbour’s property, to a depth lower than the base of their foundations.
- Within 6 metres of a neighbour’s property, if the excavation will intersect a 45° line drawn from the base of their foundations (common with basements or deep footings).
Why Compliance Matters
Failure to serve the correct notice can lead to disputes, project delays, and even legal proceedings. By securing a properly drafted Party Wall Award, you ensure that:
- Your neighbour’s property is protected.
- You retain clear legal rights to undertake the works.
- Any issues or damage can be resolved swiftly without recourse to court action.
Professional Support for Rear Extensions
At Simple Survey, we simplify the Party Wall process, ensuring compliance at every stage. Our experienced surveyors serve valid notices, prepare robust Agreements, and help you progress your project with confidence — all at the most competitive rates in the UK.
đź“© Contact us today at team@simplesurvey.co.uk for clear, no-obligation advice on your rear extension.