Clear Guidance on Excavation Near Neighbouring Properties
Planning excavation work near a neighbouring building is not just a construction decision, it is a legal one.
Section 6 of the Party Wall etc. Act 1996 sets out strict obligations that must be followed before any excavation begins. Whether you are planning a basement, extension or drainage works, understanding these requirements early can help you avoid delays, disputes and unexpected costs.
In this guide, we explain when Section 6 applies, what you are legally required to do, and how to protect both your project and neighbouring properties.
Why Getting Professional Advice Early Matters
Party wall matters are often misunderstood until a problem arises. Taking advice early allows you to move forward with confidence and avoid costly mistakes.
Working with experienced, RICS-qualified surveyors ensures:
- Clear, practical advice tailored to your project
- Legally compliant notices prepared correctly first time
- Fixed, transparent fees with no hidden costs
- Support whether you are a building owner or adjoining owner
- A smoother process that keeps your project on track
If you are unsure where you stand, speaking to a surveyor before works begin can save significant time and stress later.
What is Section 6 of the Party Wall Act?
Section 6 of the Party Wall etc. Act 1996 deals specifically with excavation work carried out near neighbouring properties.
It applies where digging takes place close enough to potentially affect the foundations of an adjoining building. In these situations, the law requires the building owner to formally notify affected neighbours before work begins.
In simple terms, if your excavation is deeper than your neighbour’s foundations and within a defined distance, you must serve notice.
Section 6 sits alongside Section 1, which relates to boundary walls, and Section 2, which covers party walls. It is often the least understood part of the Act, yet one of the most important when it comes to structural risk.
If your project also involves work to a shared wall, you may need to consider obligations under Section 2 as well.
When Does Section 6 Apply?
Section 6 is triggered by both distance and depth. It is not enough to consider how close you are to a neighbouring property, you must also consider how deep you are excavating.
You must serve a Section 6 notice if:
- Your excavation is within 3 metres of a neighbouring building and will go deeper than its foundations
- Your excavation is within 6 metres and intersects a 45 degree line drawn from the bottom of the neighbour’s foundations
This second scenario is often referred to as the 45 degree rule. It exists because deeper excavations can affect the ground stability supporting nearby structures, even at a greater distance.
Common projects that trigger Section 6
- Basement excavations
- Extensions with deep foundations
- Drainage installations
- Swimming pool construction
If you are planning a basement in London or surrounding areas, Section 6 will almost always apply.
How to Serve a Section 6 Notice Properly
Serving notice correctly is one of the most important parts of the process. Errors can invalidate the notice and lead to delays.
Step 1: Identify all adjoining owners
You must notify everyone affected, including both freeholders and tenants where applicable.
Step 2: Prepare the notice
The notice must clearly set out:
- Your name and address
- Details of the proposed works
- The site address
- The proposed start date
- Plans showing excavation depth and location
Step 3: Serve the notice
You must serve notice at least one month before the intended start date.
Step 4: Allow time for a response
Neighbours have 14 days to respond. They can consent, dissent and appoint a surveyor, or not respond at all, which is treated as dissent.
Step 5: Proceed in line with the outcome
If a dispute arises, a party wall award must be agreed before work can begin.
For a more detailed breakdown, see our guide to Party Wall Notices.
Your Neighbour’s Rights Under Section 6
The Act is designed to protect adjoining owners and ensure their property is not put at risk.
They have the right to:
Consent or dissent
They can approve the works or trigger the formal dispute process.
Appoint a surveyor
If they dissent, they can appoint a surveyor at your expense.
Have their property protected
You must take appropriate measures to safeguard their structure, including underpinning where required.
Access for inspection
Surveyors have the right to access the site to monitor compliance with the party wall award.
If you have received a notice and are unsure how to respond, seeking professional advice early is always recommended.
Your Responsibilities as the Building Owner
As the person carrying out the works, you have clear legal responsibilities.
You must:
- Serve valid notice at least one month before starting
- Provide accurate and detailed plans
- Pay reasonable surveyor costs
- Protect neighbouring structures throughout the works
- Repair or compensate for any damage caused
- Comply fully with the party wall award
Failure to meet these obligations can result in delays, disputes and legal action.
Working with a Party Wall Surveyor London helps ensure everything is handled correctly from the outset.
Why a Schedule of Condition is So Important
A schedule of condition provides a detailed record of the neighbouring property before works begin.
This includes photographs and written notes of any existing defects.
It plays a crucial role in:
- Preventing disputes
- Protecting both parties
- Providing clear evidence if damage occurs
Without this record, disagreements about damage can quickly become complex and costly to resolve.
You can arrange this as part of a Schedule of Condition Survey before works begin.
What Happens If You Ignore Section 6?
Ignoring Section 6 requirements can have serious consequences.
Injunctions
Neighbours can apply to stop your project through the courts.
Financial claims
You may be liable for repair costs if damage occurs.
Project delays
Work may be halted until proper procedures are followed.
Insurance complications
Some policies may not cover works carried out without compliance.
In most cases, the cost of getting professional advice early is far lower than dealing with disputes later.
Local Party Wall Surveyors in London and the Home Counties
We support homeowners, developers and property professionals across:
- Greater London
- Surrey
- Kent
- Hertfordshire
- Essex
Our experience with excavation projects in built-up areas means we understand the risks, the regulations and how to manage the process efficiently.
Need Help with a Section 6 Notice?
If you are planning excavation works or have received a notice, getting the right advice early can save time, money and unnecessary stress.
Our RICS-qualified surveyors provide clear, practical guidance and manage the process from start to finish.
Book a Free Consultation Today
Call 020 8541 4111
Email admin@simmonstaylorhall.co.uk
No obligation. Fixed fees. Fast turnaround. Serving London and the Home Counties.
