If your project involves digging new foundations close to a neighbour, Section 6 of the Party Wall etc. Act 1996 almost certainly applies. And Section 6 isn’t vague about what a valid notice must contain: plans and sections showing the site and depth of the proposed excavation/foundations, and whether you intend to underpin, strengthen or safeguard the neighbour’s foundations.
Miss those drawings, and your notice is invalid. No grey area. No “we’ll send them later.” You must re-serve a compliant notice and restart the clock.
Below is a clear guide to what’s required, why missing drawings cause problems, and how to fix things fast.
What Section 6 actually requires
A Section 6 (Adjacent Excavation) notice is triggered when you plan to:
- Excavate within 3 metres of a neighbouring structure to a lower level than its foundations; or
- Excavate within 6 metres where the excavation would intersect a 45° line drawn down from the neighbour’s foundation toe.
To be valid, the notice must be accompanied by:
- Plans and sections showing:
- The position (plan) of your new excavation/foundations relative to the neighbour’s building;
- The depth (section) of your excavation/foundations; and
- The site of any proposed building or structure.
- A statement confirming whether you will underpin, strengthen or safeguard the neighbour’s foundations (where necessary).
These aren’t “nice-to-haves”. They’re the legal minimum so an Adjoining Owner (and any surveyor they appoint) can assess risk and impact.
Why missing drawings make the notice invalid
Without scaled plans and sections showing where you’ll dig and how deep, your neighbour can’t make an informed decision. The Act recognises that; hence the explicit requirement. An incomplete Section 6 notice:
- Doesn’t start the statutory clock (the one-month notice period hasn’t lawfully begun);
- Can be ignored by the Adjoining Owner without consequence; and
- Leaves you open to injunction risk if you break ground assuming “silence means consent.”
If you’ve already served a notice without the drawings, the remedy is simple: withdraw and re-serve a fully compliant notice.
Consequences for your programme
An invalid notice wastes time. You’ll have to:
- Prepare proper drawings (plan and section) and, where relevant, a short note on safeguarding measures;
- Re-serve the Section 6 notice(s);
- Wait one calendar month (unless the neighbour formally waives the period in writing).
Trying to “patch” an invalid notice by drip-feeding sketches rarely works and can undermine trust. It’s quicker to get it right and re-serve.
What “good” Section 6 drawings look like
You don’t need a glossy pack—just clear, scaled information:
- Plan: boundary line, neighbour’s wall footprint, your excavation/foundation line, dimensioned offsets (e.g., 2.1m from boundary).
- Long/short sections: proposed formation level, foundation type (e.g., trench fill at -1.2m; piles at -6.0m with caps at -1.0m), and relative depth to the neighbour’s assumed foundation.
- Notes: if you will underpin or safeguard, say so. If not, state why not (e.g., “excavation staged in 1.0m bays; no bearing on neighbour’s substructure”).
If you don’t know the neighbour’s exact foundation depth (common with older stock), your engineer can provide a reasonable assumption from experience, trial pits, or building control records.
Common DIY pitfalls (and how to avoid them)
- No sections: a plan alone doesn’t show depth—which is the whole point of Section 6.
- Not dimensioned: “near the boundary” won’t do; show offsets and levels.
- Wrong trigger test: confusing 3m/6m and the 45° rule leads to mis-served notices.
- No safeguarding statement: the Act expects you to address how you’ll protect the neighbour’s foundations where necessary.
Fix: get an engineer/surveyor to prepare the right drawings and serve the notice properly.
If you’re the Adjoining Owner
Received an excavation notice without plans and sections? You can reply that the notice is invalid and request a compliant re-service. Don’t feel pressured to respond substantively until you have the required information—you’re not being difficult; you’re asking for the legal minimum so you can assess risk.
Best practice for Building Owners
- Engage your engineer early to produce simple plan/section drawings with levels.
- Serve one clean pack: notice + plans/sections + safeguarding note.
- Don’t break ground on notifiable elements until the notice period ends or is waived and, where there’s a dissent, an award is in place.
- Keep it friendly: a brief cover letter explaining the method and sequencing calms nerves and speeds decisions.
Not sure? Avoid DIY notices—use a surveyor
We see it every week: a well-meaning DIY notice goes out without the required drawings, everyone loses a month, programmes slip, and relationships strain. For the cost of a takeaway, you can have it done correctly first time.
Simple Survey — RICS Party Wall Surveyors
- Party Wall Notice service: £25 per adjoining ownership (multi-notice bundles discounted)
- Act administration as Agreed Surveyor (single surveyor): typically £300 fixed fee (depends on complexity/number of owners)
- Two-surveyor route (we act for the Building Owner): fixed-fee proposals from £325 for our side (we work to keep your neighbour’s surveyor’s hourly fees reasonable and contained)
Need your Section 6 notice and drawings sorted fast—and valid?
Email team@simplesurvey.co.uk and we’ll get a compliant pack out, keep your programme moving, and keep everyone onside.