When works affect a party wall/party structure, the Building Owner must usually serve a Party Structure Notice under Section 2 of the Party Wall etc. Act 1996. Below are the most common categories—what they involve, why they’re notifiable, and practical notes to keep projects safe and compliant.
1) Cutting Into a Party Wall
Typical examples include:
- Steel beams, posts, and box-frames: Common in open-plan layouts, chimney breast removals, large openings (e.g., bi-folds), or loft conversions. Seating or pocketing steel into a party wall is a classic Section 2 trigger.
- Chasing for weathering or moisture control: Cutting grooves to install lead flashings or a damp-proof course (DPC) alters the fabric of the party wall and is generally notifiable.
- Joist seats / wall plates / hangers: If the work cuts into the party wall or alters its load path, it’s typically notifiable. Where fixings are superficial and do not involve cutting/structural change, the duty may be less clear—get specific advice for your detail.
- Recesses, niches, alcoves: Creating openings in a party wall is cutting-in and therefore notifiable.
2) Cutting Off Projections From a Party Wall
- Chimney breast alterations/removals on a party wall are notifiable. Works often require temporary support, make-good, and careful coordination where live flues exist next door.
- Other projections (e.g., nibs, pilasters, corbels) fixed into or forming part of the party wall are likewise notifiable when removed or trimmed.
3) Raising, Lowering, Underpinning, Demolishing & Rebuilding a Party Structure
- Raising or reducing height of a party wall;
- Underpinning (strengthening foundations beneath a shared wall);
- Demolition and reconstruction (either like-for-like, or rebuilding as a new party wall).
Compliance Snapshot (for Building Owners)
- Serve a Party Structure Notice (Section 2) at least 2 months before the intended start.
- If the Adjoining Owner consents, that is the end of the matter.
- If the Adjoining Owner dissents (or doesn’t reply), appoint surveyor(s) and obtain a Party Wall Award before starting.
- Keep design unchanged from what was notified. Material changes usually require a fresh notice.
- Coordinate with planning and building control—these are separate from the Party Wall process.
Want a fast check on whether your detail is notifiable?
Email team@simplesurvey.co.uk—the lowest-cost party wall surveyors across England & Wales—for a quick compliance review, properly drafted notices and efficient Party Wall Awards.