Party Wall Act 3 Metre Rule

Expert Guidance on Your Legal Obligations

Planning excavation works near your neighbour’s property? The 3 metre rule under the Party Wall etc. Act 1996 may legally apply to your project.

At Simmons Taylor Hall, our RICS Chartered Building Surveyors ensure:

Correct Party Wall Notices are prepared and served
Foundation depths and risk are properly assessed
Neighbour concerns are professionally managed
The Party Wall process is handled efficiently and lawfully

If you are unsure whether the 3 metre rule applies to your works, speak to our team before construction begins.

What Is the Party Wall Act 3 Metre Rule?

The 3-metre rule relates to excavation works close to neighbouring buildings.

You must serve formal written notice on your adjoining owner if:

You plan to excavate within 3 metres of a neighbouring structure
Your excavation will go deeper than the bottom of their foundations

This applies to any part of their property, not just the shared boundary line. If your proposed works meet both conditions, you are legally required to serve what is commonly referred to as a “Three Metre Notice”.

When Does the 3 Metre Rule Apply?

The rule most commonly applies to:

Rear or side extensions
Basement excavations
Structural underpinning
Large foundation works
New builds close to existing properties

If the lowest point of your excavation will be lower than the underside of your neighbour’s foundations and within 3 metres of their structure, the Act is triggered.

This includes situations where the excavation is not directly next to the boundary but still falls within the 3 metre zone.

If you are also carrying out works to a shared wall, you may additionally require a Party Wall Notice under other sections of the Act.

View our Party Wall Survey page.

What Happens After You Serve Notice?

Once served, your neighbour has three options:

Provide written consent
Dissent and appoint the same surveyor (agreed surveyor)
Dissent and appoint their own surveyor

If they dissent, a Party Wall Award will be prepared. This is a legally binding document that sets out:

The scope of works
Safeguards to protect the adjoining property
A schedule of condition
Access arrangements
Procedures in the event of damage

Our role is to ensure the process is fair, compliant, and proportionate.

Why Professional Advice Matters

The Party Wall Act is technical legislation. Misunderstanding it can lead to:

Project delays
Increased costs
Strained neighbour relationships
Legal disputes

As RICS regulated Chartered Surveyors, Simmons Taylor Hall provide structured, impartial advice. We act for building owners, adjoining owners, or as agreed surveyors.

If you are at planning stage, now is the right time to speak to us.

How Simmons Taylor Hall Can Help

We offer:

Advice on whether the 3 metre rule applies
Preparation and service of valid Party Wall Notices
Schedule of condition reports
Party Wall Awards
Dispute resolution
Liaison with neighbours and contractors

Our team has over 35 years of experience advising across residential and commercial property.

Frequently Ask Questions

Is the 3 metre rule measured from the boundary line?

No. It is measured from the neighbouring structure itself. If your excavation is within 3 metres of any part of their building and deeper than their foundations, notice is required.

How do I know how deep my neighbour’s foundations are?

This can sometimes be estimated based on age and construction type, but in certain cases trial pits or structural information may be required. A surveyor can advise you.

What happens if I do not serve notice?

Your neighbour could seek an injunction to stop works. You may also face claims for damage or increased professional costs.

Does the rule apply to small extensions?

It can. Even modest extensions may require deeper foundations that trigger the Act. The key factors are depth and proximity.

How long does the Party Wall process take?

If neighbours consent, the process can be straightforward. If surveyors are appointed, it typically takes several weeks depending on complexity and responsiveness.

What Our Clients Say

We are proud of the feedback we receive from clients across Surrey and London.

We aim to make what can feel like a complicated legal process straightforward and manageable.

      EXCELLENT  
   Based on 9 reviews 
    
 
 
 
   
 
 
       Posted on Google  
   
   veronica houghton 
 
 
 
 Trustindex verifies that the original source of the review is Google. I found surveyor Nick Sharp most professional and personable. His knowledgeable, speedy responses to calls and emails made for a refreshing experience. I highly recommend him and his team at Simmons Taylor Hall.
  
 
      Posted on Google  
   
   Warren Lloyd 
 
 
 
 Trustindex verifies that the original source of the review is Google. Nick was a tremendous help with surveying our home and providing a timely report. He also arranged for our Party Wall Award, which was at times quite testing. He was professional and experienced all the way through. We will use him again if we ever needed too.
  
 
      Posted on Google  
   
   Sandra 
 
 
 
 Trustindex verifies that the original source of the review is Google. In my search for a new home, STH had the dubious “privilege” of providing me with three (!) building surveys on three prospective properties.  Thankfully, the third survey passed muster and gave me the assurance to complete on the purchase.

Communication with Trevor, Nick and the team was excellent.  They were approachable and knowledgeable, and the sound, professional advice received was greatly appreciated.  I would certainly use STH again and have no hesitation in recommending them to you.
  
 
      Posted on Google  
   
   Arisha Patel 
 
 
 
 Trustindex verifies that the original source of the review is Google. Nick at STH came to survey a property for me. Communication with Nick and Joy was extremely prompt and professional. I would definitely use them again in the future!!
  
 
      Posted on Google  
   
   Oliver Boggis 
 
 
 
 Trustindex verifies that the original source of the review is Google. I instructed STH to undertake a party wall award between my company and a neighbour. Nick was prompt, professional and a pleasure to deal with. Many thanks for your help.
  
 
      Posted on Google  
   
   Brandon Winchester 
 
 
 
 Trustindex verifies that the original source of the review is Google. Couldn't be happier with the service that was provided. For reliability and efficiency, I couldn't have asked for anything more. Strongly recommend!