If you’re planning an extension, loft conversion, basement, or any work near a boundary, the Party Wall etc. Act 1996 may require you to serve a formal Party Wall Notice on affected neighbours before you start. Doing this properly keeps your project legal, avoids injunctions and delays, and sets a clear process if concerns arise.
When must a Party Wall Notice be served?
Notices are required before certain works that could affect a neighbour’s structure or a shared wall. Typical triggers include building a new wall at or astride the boundary, cutting into or altering a party wall/party structure (e.g., for steel beams, DPCs, raising or rebuilding), and excavating close to a neighbour’s foundations.
Timing matters:
- Section 2 (works to a party wall/structure): serve at least 2 months before works.
- Sections 1 & 6 (new boundary walls and adjacent excavation): serve at least 1 month before works.
- Validity: a notice expires after 12 months if you haven’t started.
That common line you may have heard—“serve between two months and a year”—isn’t quite right. The Act sets different minimum notice periods (1 or 2 months), and all notices lapse after 12 months.
What is a “party wall” and “party structure”?
The Act recognises several shared elements:
- Party wall (Type A): a wall standing astride the boundary, forming part of one building or separating two buildings.
- Party fence wall: a freestanding masonry wall astride the boundary (garden wall)—not timber fences or hedges.
- Party wall (Type B): a wall wholly on one owner’s land that the neighbour uses to separate buildings (only the “separating” part is party).
- Party structure: broader than walls—includes floors/partitions separating parts of buildings (e.g., flats).
The three Party Wall Notices—and when to use each
1) Party Structure Notice (Section 3, for works under Section 2)
Use this when you intend to work on an existing party wall or party structure, such as:
- Cutting in steel beams or a damp-proof course.
- Removing a chimney breast from the party wall.
- Raising, underpinning, demolishing/rebuilding a party wall or party fence wall.
- Cutting flashings where your new wall abuts the party wall.
- Enclosing on a party fence wall that stands astride the boundary.
Serve at least 2 months before the planned start.
2) Line of Junction Notice (Section 1)
Use this when building a new wall on the line of junction (the boundary) or up to it on your land. If you want the new wall to sit astride the boundary, you must obtain the Adjoining Owner’s written consent; otherwise you must place it wholly on your land.
Common example: a rear extension that spans the full width and runs up to (or seeks to sit astride) the boundary.
Serve at least 1 month before the planned start.
3) Adjacent Excavation Notice (Section 6)
Use this when you’ll excavate near a neighbour’s structure:
- Within 3 metres and deeper than the bottom of their foundations, or
- Within 6 metres where your excavation would intersect a 45° line drawn down from the bottom of their foundations.
This applies to substructure works, foundations (including piles), drains, manholes, and trial holes. If you don’t know the neighbour’s foundation depth, proceed cautiously and serve notice—Section 6 exists to prevent destabilisation.
Serve at least 1 month before the planned start, and include plans and sections showing the location and depth of your excavation relative to the neighbour’s structure. Omitting these drawings will invalidate a Section 6 notice.
What happens after you serve notice?
The Adjoining Owner has 14 days to respond by consenting or dissenting.
- Consent: you can proceed (after the statutory lead-in).
- Dissent (or no reply): a dispute is deemed to have arisen and a Party Wall Award is needed—either via an Agreed Surveyor (one impartial surveyor acting for both) or two surveyors (one for each owner). The Award sets how and when the works are done and provides a route to resolve issues fairly.
Common pitfalls that invalidate notices
- Using the wrong notice for the work.
- Missing/incorrect owner names and addresses (both building and adjoining owners).
- Vague descriptions (e.g., “loft works”) instead of clear particulars of the party work.
- For Section 6, no excavation drawings (plan and section with depths).
- Serving too late—or letting the 12-month validity lapse.
Getting the notice right first time saves weeks. If a notice is invalid, you’ll have to re-serve and restart the clock.
If you want help identifying which sections apply and having compliant notices prepared and served quickly (with the right drawings where required), a specialist Party Wall surveyor can keep your programme on track and neighbour relations positive.
Make it easy: have Simple Survey serve your notices
We prepare and serve correct, fully compliant notices across England & Wales, keep neighbour communications friendly, and—if there’s a dissent—coordinate the next steps so a fair Party Wall Award is agreed quickly.
Transparent, low pricing:
- 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 and number of notices/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)
Ready to get this right first time?
Email team@simplesurvey.co.uk and we’ll take it from here—fast, friendly, and fully compliant.