When does Section 6 apply?
Excavation becomes notifiable under the Party Wall etc. Act 1996 if either of these tests is met:
- The 3-metre test (s.6(1))
- You propose to excavate within 3 metres (measured horizontally) of any part of an Adjoining Owner’s building or structure and
- Your excavation will go lower than the bottom of that building’s existing foundations.
- The 6-metre / 45° test (s.6(2))
- You propose to excavate within 6 metres of the Adjoining Owner’s building and
- If you draw a line from the bottom of your excavation back toward the Adjoining Owner’s foundations at 45°, that line intersects their foundations.
(This commonly captures piled or deep excavations a little further away.)
In short: it’s not just “within 3m and deeper.” The 6m/45° rule also triggers Section 6 in many loft-to-basement or rear-extension schemes.
Who is an “Adjoining Owner” when next door is flats?
Section 20 defines “owner” broadly. In a typical converted terrace with a freeholder and individual leaseholders:
- Freeholder (or head-lessee with the superior interest): Adjoining Owner
- Each leaseholder with an interest exceeding a year whose premises are within the distance tests: Adjoining Owner
- A Right to Manage company or management company isn’t an “owner” unless it actually holds a proprietary interest, but they’re often copied in for practicality.
Practical example
Victorian terrace next door split into two flats:
- Freeholder of the building — serve a Section 6 Notice
- Ground-floor leaseholder (term > 1 year) — serve a Section 6 Notice
- First-floor leaseholder (term > 1 year) — serve a Section 6 Notice
Why include the upper flat? Because Section 6 looks at the building’s foundations and uses horizontal distance from the building/structure — not just the bit directly opposite the work. The definition of owner expressly captures “storeys” for the purposes of s.6; upper-storey leaseholders are Adjoining Owners where the statutory distance/depth tests are met.
Tip: In mansion blocks or larger conversions, expect to serve multiple Section 6 Notices—on the freeholder and every leaseholder (with >1-year interest) whose demise is within the 3m/6m tests.
What must a Section 6 Notice include?
To be valid, a Section 6 Notice should include (in practice, attach drawings):
- The names/addresses of Building Owner(s) and Adjoining Owner(s)
- The site address and description of proposed excavation
- Depths relative to the Adjoining Owner’s foundations
- Plans and sections showing existing and proposed levels (crucial)
- Start date (at least 1 month after service)
- Reference to the relevant subsections (s.6(1) and/or s.6(2))
- Service method (post, hand, or by email only if the recipient has consented to electronic service)
Lead-in time: Minimum 1 month before works start.
Response time: The Adjoining Owner has 14 days to consent or dissent. No reply = deemed dissent, triggering surveyor appointments under Section 10 and a Party Wall Award before works proceed.
Special points to watch
- Special foundations: If you intend to bear onto reinforced concrete that projects under the Adjoining Owner’s land (i.e., “special foundations”), you’ll need their express consent—an Award alone can’t authorise them without it.
- Design changes: Material changes (depths, positions, method) usually require fresh notices.
- Co-ordination with Section 1/2: Many schemes trigger Section 2 (works to the party wall) and/or Section 1 (new wall at the boundary) as well as Section 6. Serve all relevant notices together for a clean process.
Quick checklist before serving Section 6 Notices
- Confirm whether 3m and/or 6m/45° tests are met
- Compile a complete owner schedule (freeholder + all qualifying leaseholders)
- Prepare plans/sections with levels and proposed depths
- Set a start date ≥ 1 month from service
- Serve individual notices on each Adjoining Owner
- Diary the 14-day response and, if needed, the 10-day s.10(4) letter
- Line up surveyor(s) in case of dissent/no reply
Want us to map all the Adjoining Owners and draft the Section 6 pack?
Email team@simplesurvey.co.uk. As the lowest-cost party wall surveyors across England & Wales, we’ll identify every party you must notify, prepare compliant Section 6 notices with plans/sections, and handle Awards swiftly where required.