What If an Extension Requires Piled Foundations Near a Neighbouring Property?
If piling for an extension falls within 3 or 6 metres of a neighbouring building and goes below its foundations, you need to serve notice under Section 6. Piling is closer to the neighbour's concerns than most work, so expect a detailed award covering method, monitoring and records.
Why piles are treated seriously
Piles are driven or bored deep into the ground. Some methods cause vibration or noise, and all disturb the soil to some degree. Neighbours worry about cracks, and older houses may be sensitive.
Piling is a form of excavation for the purposes of the Act, and it will usually exceed the depth of a neighbour's foundations. That is what engages Section 6.
Notice and drawings
Notice must be served at least 1 month before starting and must include plans and sections showing the proposed work. The pile layout, depth and method should be drawn so that the neighbour's surveyor can assess the risk. Vague notices tend to cause delay.
Things the award may address
- A schedule of condition of the neighbour's property, in detail
- Choice of piling method, for example bored rather than driven, if the engineer agrees
- Working hours and noise
- Vibration or movement monitoring, with agreed trigger levels
- Access for inspections
- Security for expenses if requested
Your engineer's role
A structural or geotechnical engineer chooses the foundation type, not the surveyor. Your engineer's information is what lets the surveyors judge whether the neighbour's protection is adequate. Share it early. If the two surveyors disagree, the third surveyor decides.
Choosing a surveyor
Ask whether they have handled awards with piling or deep excavation, and how they deal with monitoring. Get quotes in writing and ask what happens to fees if the neighbour's surveyor requires more information. Costs depend on the complexity of the work and how contested it becomes.
Frequently asked questions
Is piling always covered by the Act?
Only if it meets the Section 6 distance and depth tests. Your surveyor can check this from the plans.
Can the neighbour ban piling?
They cannot simply veto it. The award decides how work proceeds, and either owner can appeal it.
Who pays for monitoring?
Usually the building owner, if the award says so.
Related guides
- Understanding Section 6 of the Party Wall Act: Excavation Within 3 or 6 Metres
- Party Wall Rules for Home Extensions
- Excavations and Foundational Underpinning: Party Wall Rules Explained
- Security for Expenses: Protecting Against Unfinished Work
Last updated: . This page is general information about the Party Wall etc. Act 1996 (England and Wales). It is not legal advice. Every property and dispute is different, so take advice from a party wall surveyor or a solicitor before you act.