If you’re planning building work in London—like a loft conversion, rear extension, or excavation for foundations—you may need to serve a Party Wall Notice under the Party Wall etc. Act 1996. The notice is a formal way to tell adjoining owners what you plan to do, when you plan to do it, and how the work could affect shared structures or nearby foundations.
This guide explains the most common notice types, typical timelines, who must receive notice, and how to avoid the mistakes that cause delays.
When Do You Need a Party Wall Notice?
You may need to serve a party wall notice if your work involves:
- Working on a shared wall between two properties (party wall)
- Building on or near a boundary line (new wall at the line of junction or boundary wall works)
- Excavating near a neighbour’s foundations (often within 3 metres, sometimes 6 metres depending on depth)
In London, this comes up frequently because homes are close together—terraces, semis, and flat conversions often share walls or sit near boundaries.
The 3 Common Types of Party Wall Notice
1) Party Structure Notice (works to a party wall)
Used when you’re doing work directly to a shared structure, such as:
- Cutting into a party wall for steel beams (common with loft conversions)
- Removing chimney breasts attached to a party wall
- Raising, thickening, or repairing a party wall
2) Notice of Adjacent Excavation (excavation near foundations)
Used when excavating for foundations close to a neighbour’s building, typically for:
- Rear/side extensions
- Deeper footings
- Basement or underpinning works
3) Line of Junction Notice (new wall at the boundary)
Used when you plan to build a new wall on the line of junction (boundary line). This can apply to garden/boundary walls as well as certain extension layouts.
When to Serve a Party Wall Notice (Timing)
Timing depends on the notice type, but a practical rule is: start early. Even when neighbours are friendly, you need time for responses and (if needed) surveyor steps.
- Party Structure Notice: typically served at least 2 months before works begin
- Adjacent Excavation Notice: commonly at least 1 month before excavation begins
- Line of Junction Notice: commonly at least 1 month before building begins
Note: If a neighbour dissents or doesn’t respond, the process can take longer because surveyors may need to agree an Award.
Who Must Receive the Notice?
This is where many people go wrong. You must serve notice on the correct legal owners, which can include:
- Freeholders
- Leaseholders (often if leases are long)
- Multiple owners in flat buildings
If you serve the wrong person, the notice can be treated as invalid—leading to delays and re-serving.
What Should the Notice Include?
A typical notice should include:
- Your name and address (building owner)
- The neighbour’s name and address (adjoining owner)
- Clear description of the proposed works
- Proposed start date
- Relevant drawings (recommended, especially for excavation/structural work)
For excavation notices, details like foundation depth and distance can be essential.
What Happens After the Notice?
A neighbour can:
- Consent (in writing)
- Dissent (surveyors are appointed and an Award is usually agreed)
- Not respond (the process can still continue, but becomes more formal)
Even when neighbours consent, many owners still choose a Schedule of Condition to record the neighbour’s property condition before works start.
Common Mistakes That Cause Delays
- Serving the notice too late (builder booked before paperwork)
- Serving the wrong owner (especially flats/leasehold)
- Unclear work descriptions (“extension” without details)
- No drawings for excavation work
- Not keeping written records of consent
Need a Surveyor in Your Area?
Compare local surveyors by borough:
- Party Wall Surveyor London
- Party Wall Surveyor Islington
- Party Wall Surveyor Camden
- Party Wall Surveyor Hackney
- Party Wall Surveyor Southwark
FAQs
Do I need a surveyor to serve a notice?
Not always, but many homeowners use a surveyor to avoid invalid notices and to keep the process organised—especially for excavation and flats.
What if my neighbour refuses?
A neighbour can dissent, which triggers the surveyor process and usually leads to a Party Wall Award. Dissent doesn’t automatically stop work—it formalises the protections and rules.
Can I start work once I serve the notice?
No. You must allow the required notice period and handle any dissent/Award steps before starting the relevant works.
Next read: Party Wall Award Explained