When planning construction work near a neighbouring property, it’s important to consider how your project might affect those around you. One key part of this process in England and Wales is the Party Wall etc. Act 1996, which includes various rules designed to protect neighbouring structures. Among them is something known as the 6 metre rule.
This blog explains what the 6 metre rule is, when it applies, and how it might impact your building plans. Whether you’re building an extension, basement, or new structure, understanding this rule can help avoid delays, disputes, and costly legal issues.
What Is the 6 Metre Rule?
The 6 metre rule is part of Section 6 of the Party Wall Act. It applies when you are planning to carry out deep excavations within six metres of a neighbouring property or structure.
This rule is particularly relevant when foundations go deeper than those of the adjoining building. In most cases, it comes into play for projects such as:
- Basement excavations
- Foundations for large extensions
- Piling work or retaining walls
- Substantial underpinning
The aim of the 6 metre rule is to protect neighbouring buildings from damage that could result from your excavation work.
How Does It Work?
The way the 6 metre rule is applied depends on how deep your foundations are and how close your work is to a neighbour’s structure.
There’s a simple method used to calculate whether your excavation falls under this rule. It’s called the “45-degree line” test.
Imagine a 45-degree line drawn from the bottom of the neighbour’s foundations, angling downwards towards your proposed excavation. If your excavation cuts across that line, and it’s within six metres of the boundary, the 6 metre rule applies. In this case, you must serve a Section 6 Notice under the Party Wall Act.
When Must a Section 6 Notice Be Served?
You need to serve a Section 6 Notice on your neighbour (referred to as the Adjoining Owner) at least one month before starting any excavation work. This is a legal requirement if:
- Your excavation is deeper than the foundations of the neighbouring property
- The excavation is within 3 to 6 metres of the boundary
It’s worth noting that if your excavation is less than three metres from the boundary and deeper than the neighbour’s foundations, this also falls under a separate part of Section 6, known as the 3 metre rule.
In both cases, notice must include detailed information such as:
- A clear description of the proposed works
- Depth and method of excavation
- Plans, sections and site drawings
- Start date of the excavation
What Happens After the Notice Is Served?
Once you’ve served the notice, your neighbour has 14 days to respond. They can either give written consent or dissent.
- If they consent, you can proceed as long as you follow the agreed plans
- If they dissent, or fail to respond within the time period, a party wall dispute is deemed to have arisen
In the case of a dispute, both parties must appoint a surveyor. This may be:
- A separate surveyor for each party
- A single agreed surveyor acting for both
The surveyor(s) will draw up a Party Wall Award, which sets out how the work should proceed, any protections required, and steps to limit the risk to the neighbouring structure.
Why Is the 6 Metre Rule Important?
Ignoring the 6 metre rule can lead to serious problems. Without proper notice, your neighbour could seek a court injunction to halt your project. You may also be liable for any damage caused to their property, especially if the work is carried out without the protections that would have been specified in a Party Wall Award.
From a planning perspective, this rule provides peace of mind for both you and your neighbour. It ensures that all risks are properly assessed and managed before digging begins.
What Types of Projects Are Commonly Affected?
The 6 metre rule is most likely to apply in areas with closely packed housing, such as terraced or semi-detached properties. Projects where this rule is often triggered include:
- Basement conversions in urban homes
- Two-storey rear or side extensions
- Groundworks for new homes or garden buildings
- Retaining walls for garden landscaping
Even smaller projects may be affected if they involve particularly deep foundations or are very close to the boundary.
Is the 6 Metre Rule the Same as Planning Permission?
No, the 6 metre rule is completely separate from planning permission or building regulations. Even if your project has planning approval, you still need to comply with the Party Wall Act if your excavation meets the criteria.
Think of it as another step in the legal process before construction begins. It’s always best to factor this into your project timeline to avoid delays.
How Can a Party Wall Surveyor Help?
Simmons Taylor Hall can guide you through the entire process, from assessing whether the 6 metre rule applies to serving notices, managing neighbour relations, and drafting the Party Wall Award if needed.
Surveyors can also carry out a Schedule of Condition before work begins, which records the condition of your neighbour’s property. This acts as evidence should any damage occur, helping to resolve disputes fairly.
Having expert advice early on can make the difference between a smooth build and a project filled with obstacles.
Final Thoughts
The 6 metre rule in the Party Wall Act might seem like a small detail, but it has a big impact on how building projects should be managed. If your excavation work is within six metres of a neighbour’s property and deeper than their foundations, this rule applies, and a legal notice must be served.
By following the process set out in Section 6, you protect yourself from legal disputes, maintain good relations with neighbours, and ensure your project stays on track. Ignoring it could lead to delays, added costs, and the risk of damage claims.
If you’re unsure whether the 6 metre rule applies to your building plans, speaking to a qualified party wall surveyor is a smart first step.
