Party Wall Notice Explained: The 3 Metre Notice and Section 6 Excavation Rules
If you are planning to excavate for an extension, basement, or structural foundations close to a neighbouring property, you may be legally required to serve a Party Wall Notice — specifically a Section 6 notice, often referred to as a 3 metre notice.
This article explains, in practical terms, when a Party Wall Section 6 notice is required, how the 3 metre and 6 metre excavation rules work, what information must be included in the notice, and how disputes are resolved if your neighbour does not consent.
The guidance applies throughout England and Wales and is based on the Party Wall etc. Act 1996, with references included so you can verify the legal position if needed.
If you want professional help preparing or serving a Party Wall Notice, Graham Kinnear Property Consultants can manage the process correctly from start to finish.
Contact Graham Kinnear Property Consultants to discuss your project and avoid costly mistakes.
What Does Party Wall Section 6 Cover?
Section 6 of the Party Wall etc. Act 1996 applies to certain types of excavation carried out near neighbouring buildings.
In simple terms, Section 6 is triggered when you plan to excavate:
- Within 3 metres of a neighbour’s building and deeper than the neighbour’s foundations, or
- Within 6 metres of a neighbour’s building and your excavation intersects a 45-degree line drawn downwards from the neighbour’s foundation level
Where Section 6 applies, you must serve a Party Wall Section 6 Notice at least one month before excavation starts.
If your neighbour does not provide written consent within 14 days, the law treats this as a dispute, which must be resolved by surveyors through a Party Wall Award.
The 3 Metre Rule – When a 3 Metre Notice Is Required
The 3 metre notice is the most common Section 6 scenario.
You must serve a Party Wall Notice if:
- Any part of your excavation is within 3 metres horizontally of your neighbour’s building or structure, and
- Your excavation will go below the bottom of their foundations
This rule applies regardless of whether the works are small or large. Even relatively shallow trench foundations can trigger the requirement if the neighbour’s foundations are shallow.
Party Wall Act reference: Section 6(1)(a) and (b)
The 6 Metre Rule and the 45-Degree Test
The 6 metre rule involves a technical assessment rather than a simple distance check.
If your excavation is within 6 metres, Section 6 applies where the excavation would intersect a line drawn at 45 degrees downward from the neighbour’s foundation level, measured from the external face of their wall.
This situation commonly arises with:
- Piled foundations
- Deep strip foundations
- Basement excavations
If your excavation crosses this notional 45-degree plane, a Party Wall Section 6 notice must be served, even if the works are more than 3 metres away.
Party Wall Act reference: Section 6(2)(a) and (b)
What Must a Party Wall Section 6 Notice Include?
A valid Party Wall Notice under Section 6 must be served in writing and include specific information.
The notice must:
- Describe the proposed excavation works
- State whether you intend to underpin, strengthen, or safeguard the neighbour’s foundations
- Be accompanied by plans and cross-sections showing:
- The location of the excavation
- The depth of the excavation
- The position of any proposed structure
Incomplete or unclear notices are one of the most common causes of delay and dispute.
Party Wall Act reference: Sections 6(5) and 6(6)
How and When to Serve a Party Wall Notice
A Section 6 notice must be served:
- At least one month before excavation begins
- On all adjoining owners affected by the works
Service can be carried out:
- By hand
- By post
- By email only if the recipient has agreed in writing to electronic service
If works do not commence within 12 months, the notice lapses and must be re-served.
If no written consent is received within 14 days, dissent is deemed and a dispute automatically arises.
Party Wall Act reference: Sections 6(5), 6(7), 6(8), and Section 15
What Happens After You Serve a Section 6 Notice?
Once a Party Wall Notice has been served, your neighbour may:
- Consent in writing
- Consent subject to a Schedule of Condition being undertaken
- Dissent and appoint a surveyor
- Take no action, which is treated as dissent after 14 days
Where a dispute arises, surveyors are appointed under Section 10 to resolve the matter by issuing a Party Wall Award.
The Party Wall Award for Section 6 Works
A Party Wall Award will typically regulate:
- How the excavation is carried out
- Temporary works and support measures
- Access arrangements
- Monitoring and inspections
- Responsibility for costs
For higher-risk projects such as basements or deep excavations, the award may also include:
- Detailed method statements
- Movement or vibration monitoring
- Security for expenses
Your Legal Duties When Excavating Near a Neighbour
While Section 6 gives you the right to excavate, it also imposes clear obligations. You must:
- Avoid unnecessary inconvenience
- Compensate for any loss or damage caused
- Properly protect neighbouring structures
- Maintain temporary works where required
You cannot place special foundations (such as reinforced piles) on your neighbour’s land without their written consent.
Common Projects That Trigger a 3 Metre Notice
- Rear extensions with trench foundations
- Piled foundations close to boundaries
- Basement excavations
- Structural underpinning works
If you are unsure whether your project requires a Party Wall Notice, professional advice at an early stage can save time and cost.
What Happens If You Don’t Serve a Party Wall Notice?
Failing to serve a required Party Wall Section 6 notice can lead to:
- Injunctions stopping the works
- Claims for damage and delay
- Increased project risk and legal costs
The safest approach is to comply fully with the Act and document every step.
Step-by-Step: Getting Section 6 Right
- Measure distances to neighbouring buildings
- Compare excavation depth with neighbour’s foundation level
- Apply the 3 metre and 6 metre rules
- Prepare compliant plans and sections
- Serve the Party Wall Notice correctly
- Manage the 14-day response period
- Appoint surveyors promptly if required
Need Help With a Party Wall Notice or 3 Metre Notice?
Preparing and serving a compliant Party Wall Notice — particularly a Section 6 or 3 metre notice — requires technical and legal understanding.
Graham Kinnear Property Consultants provide specialist party wall services, including:
- Assessing whether Section 6 applies
- Preparing and serving valid Party Wall Notices
- Acting as Agreed Surveyor or appointed surveyor
- Managing the Party Wall Award process
Contact Graham Kinnear Property Consultants today by email or 01843 583000 to discuss your proposed works and ensure your Party Wall Notice is served correctly, on time, and without unnecessary risk.
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