Section 6 Excavation Technical Review London
Technical Party Wall review of excavation depth, neighbouring foundations, drawings and safeguards for basement and foundation works.
Section 6 is not triggered by distance alone
Section 6 can apply to excavation within 3 metres where the proposed work goes below the bottom of adjoining foundations, and within 6 metres where it crosses the statutory 45-degree plane from the bottom of those foundations.
The design information therefore matters. Plans, sections, foundation levels and the relative position of the adjoining building are needed to understand the statutory relationship properly.
This service focuses on the technical information behind the section 6 notice and any later Party Wall dispute.
Core review information
- Proposed excavation and foundation depths.
- Location of adjoining building or structure.
- Known or assumed adjoining foundation level.
- Plans and sections accompanying the notice.
- Proposed safeguarding or underpinning position.
What does the statutory test look at?
Both tests rely on geometry and foundation depth, not simply how many metres separate the buildings.
Within 3 metres
Part of the proposed excavation or foundation must also extend below the level of the bottom of the adjoining building or structure's foundations.
Within 6 metres
Part of the proposed excavation must meet a line drawn downwards at 45 degrees, in the direction of the excavation, from the bottom of adjoining foundations.
Notice drawings
Plans and sections must show the location and depth of the proposed excavation or foundations and the location of the proposed building or structure.
The technical review should support a buildable Party Wall process
Where a dispute arises, the surveyors need enough information to understand the excavation and any reasonable measures necessary to protect adjoining foundations.
The Party Wall surveyor does not become the Building Owner's structural designer. The design team remains responsible for the engineering solution.
Potential safeguards
- Underpinning or safeguarding where necessary.
- Appropriate condition evidence.
- Focused monitoring where justified.
- Defined specialist engineering input where needed.
Our Section 6 technical review process
The review is built around the statutory test, the notice drawings and the specific matters in dispute.
Check geometry
Distances, excavation depths and adjoining foundation information are reviewed.
Check notice information
Plans, sections and the safeguarding statement are checked against the proposed works.
Identify uncertainty
Unknown foundation levels or design gaps that affect the section 6 assessment are identified.
Review safeguards
Project-specific protection or specialist advice is considered where proportionate.
Support Award
The relevant technical information informs the surveyors' determination where a dispute exists.
Section 6 review fees
Section 6 technical reviews are quoted individually because the scope depends on the excavation design, foundation information, neighbouring structures and level of technical scrutiny required.
We confirm the scope and fee before instruction.
Why appoint Hourican Associates?
Section 6 is a technical notice route. Accurate plans and a clear understanding of adjoining foundation levels reduce avoidable disagreement.
Hourican Associates is a Chartered Building Consultancy specialising in Party Wall surveying across London. The firm is regulated by RICS. Richard Hourican's supplied qualifications and memberships are MFPWS, BSc (Hons), MCIOB, MCABE and AssocRICS. His Pyramus & Thisbe Society membership is company-supplied, pending a current membership record.
We review section 6 matters for extensions, basements and other foundation works across Greater London.
Related services & guidance
Section 6 Technical Review FAQs
These answers cover practical points not already explained above.
No. The excavation must also extend below the bottom of the adjoining building or structure's foundations.
No. The excavation must meet the statutory 45-degree plane drawn from the bottom of adjoining foundations in the direction of the excavation.
The available evidence and reasonable assumptions need to be assessed. Further investigation may be appropriate where the uncertainty is material to the statutory test.
The Act requires plans and sections showing the location and depth of the proposed excavation or foundations and the location of any proposed building or structure.
Yes. It must state whether the Building Owner proposes to underpin or otherwise strengthen or safeguard the adjoining foundations.
The Act allows the Adjoining Owner to require underpinning, strengthening or safeguarding so far as may be necessary because of the excavation works.
Need a Section 6 excavation review?
Send us the foundation plans, sections and available adjoining-foundation information. We can review the statutory test and the technical information supporting the notice.
Call 020 8849 8390 if you would prefer to discuss the matter first.