Section 6 Excavation Technical Review for Basement Works
Deep excavations need more than a correctly worded notice. Hourican Associates review the drawings, excavation depths, adjoining foundation relationship and proposed safeguards behind Section 6 basement and foundation works so that the Party Wall process is based on clear, workable technical information.
From Section 6 Notice to a Buildable Party Wall Award
Hourican Associates already provides a general Party Wall excavation service and a detailed Section 6 guide. This specialist service is for projects where the excavation is sufficiently complex that the technical information behind the notice and Award needs closer scrutiny.
This is particularly relevant to basements, deeper extensions, underpinning, retaining structures and piled schemes where the relationship between the proposed excavation and adjoining foundations cannot safely be understood from a simple plan alone.
The 3 Metre and 6 Metre Tests
| Section 6 issue | What needs to be established |
|---|---|
| 3 metre test | Whether excavation is within 3 metres of an adjoining building or structure and extends below the bottom of its foundations. |
| 6 metre test | Whether deeper excavation within 6 metres falls within the statutory 45-degree relationship measured from adjoining foundation level. |
| Foundation information | Whether the neighbouring foundation depth is known, reasonably established or requires further investigation. |
These tests should be applied to the actual scheme rather than guessed from property boundaries. A measured drawing, section and reliable foundation information can make the difference between a clear statutory process and a dispute caused by uncertainty.
What We Review
A technical Section 6 review may include:
- Architectural plans and sections showing the proposed basement or foundation works.
- Structural foundation layouts and excavation depths.
- The position and likely depth of adjoining foundations.
- Whether the 3 metre and/or 6 metre tests appear to apply.
- Whether underpinning, safeguarding or strengthening of adjoining foundations is proposed.
- Temporary works and excavation sequencing relevant to neighbouring structures.
- Piling, retaining walls and foundation systems close to the boundary.
- Proposed monitoring and trigger procedures where movement risk warrants them.
Why the Drawings Matter
Section 6 excavation notices require supporting information showing the location and depth of the proposed excavation and the position of the proposed building or structure. The notice also needs to address whether the Building Owner proposes to underpin or otherwise strengthen or safeguard the adjoining owner's foundations.
For complex basement works, drawings should therefore do more than establish that an excavation exists. They should allow the appointed professionals to understand where the excavation is taking place, how deep it goes and how adjoining support is maintained.
Section 6 Safeguards for Higher-Risk Works
The safeguards appropriate to a shallow extension foundation may be very different from those required for a multi-stage basement excavation. Depending on the project, issues considered in the Award can include:
- Sequence of excavation and temporary support.
- Permitted methods and agreed construction information.
- Access for reasonable inspections.
- Movement monitoring and agreed response procedures.
- Schedule of Condition evidence before works start.
- Procedures for design changes that materially affect notifiable works.
- Arrangements for dealing with damage or unexpected movement.
Related Specialist Reviews
A Section 6 issue often overlaps other basement risks. Where appropriate, we can also coordinate advice on underpinning, piling, special foundations and independent engineering review.
Section 6 Technical Review FAQs
No. Notice service is one part of the statutory process. This service focuses on whether the technical drawings and proposed safeguards provide a sufficiently clear basis for dealing with a more complex excavation.
The available evidence needs to be considered. Depending on the project, further investigation or professional assumptions may be required before the Section 6 relationship can be assessed with confidence.
No. The excavation provisions concern qualifying excavation close to adjoining buildings or structures. A detached neighbouring building can therefore still be relevant.
Yes, and for complicated schemes that is often the most useful time. Missing information can then be resolved before statutory notices and neighbour correspondence are based on an incomplete design package.