At Icon Surveyors, we regularly help building owners and homeowners navigate the requirements of the Party Wall etc. Act 1996. One of the most commonly misunderstood provisions is the 3 metre rule. So, in this blog, we’re breaking down exactly what it means, when it applies, and what you need to do if it affects your project.
What Is the Party Wall Act 3 Metre Rule?
The 3 metre rule is set out in Section 6(1) of the Party Wall etc. Act 1996. It applies specifically to excavations, or proposals to erect a building or structure, where the works are planned within three metres of an adjoining owner’s property.
When Does the 3 Metre Rule Apply?
The rule is triggered when the lowest point of the excavation is lower than the underside of the footings to the adjoining owner’s land, building(s), or structure(s), and if measured horizontally is within 3 metres.
In practical terms, this means that for a building owner wishing to exercise rights under Section 2 of the Act, the proposed works must reach a depth that exceeds that of the neighbouring property’s existing foundations. If both conditions are satisfied, the 3 metre rule applies and formal steps must be taken before work can begin.
Serving a Party Wall Notice Under the 3 Metre Rule
If your proposed excavation does fall within the scope of the 3 metre rule, the building owner is legally required to serve a Party Wall Notice on all adjoining owners whose land, buildings, or structures may be affected.
For that notice to be valid, it must:
- Clearly state that the 3 metre rule applies under Section 6(1)
- Include a section drawing that illustrates the depth of the proposed excavations and their position relative to any existing structures belonging to the adjoining owner
Serving an incomplete or incorrect notice can invalidate the process entirely, so it’s important to get this right from the outset.
How Icon Surveyors Can Help
As party wall surveyors with experience in excavation-related matters, we’re well placed to make informed assessments about the likely depth of existing foundations, often drawing on factors such as the age and construction type of the neighbouring property.
Where greater certainty is needed, Icon Surveyors have used trial pits to physically determine both the depth and position of existing foundations or concealed structures, and verify the accuracy of a proposed design. Trial pitting is typically carried out before works commence and involves excavating to depths of approximately 3-15 feet deep to assess ground conditions and reduce the risk of structural issues arising from weakened or disturbed ground.
As with all statutory obligations, misunderstanding what’s required of you can lead to costly delays or legal complications. If you’re planning a project that involves excavation, Icon Surveyors offer a free 30-minute consultation to provide impartial, expert party wall advice, so you can move forward with confidence.
