Need a schedule of condition? Get a fee proposal the same working day.
Fast Track Quotation →Line of Junction Notice
A line of junction notice is served under section 1 of the Party Wall etc. Act 1996. It is the formal document a building owner serves on a neighbour when they intend to build a new wall either astride the boundary line or up to it. It is a commonly missed step in extension and boundary-wall projects.
Section 1 is narrower than section 2 and section 6, but its scope is wider than most homeowners expect. New garden walls, new outbuildings, and new external walls of extensions frequently fall within it. This page covers what the notice is, when it applies, what it must contain, and how the neighbour may respond. For the wider framework, see the Party Wall etc. Act 1996 guide.
What It Is
A statutory notice served under section 1 of the Party Wall etc. Act 1996 where a new wall is to be built at the boundary.
When It Applies
New walls astride or up to the line of junction — extensions, outbuildings, and garden or boundary walls.
Why It Matters
Without a section 1 notice the works are not lawful under the Act, and the building owner is exposed to injunction risk.
The key point
The line of junction is a physical feature on the ground, not simply the legal boundary shown on a title plan. Where a new wall is being built up to or across it, the Act requires a written notice even if the neighbour is content in principle.
If your design includes a new boundary wall, outbuilding, or extension flanking a neighbour, send us the drawings. We will confirm whether a section 1 notice is required and draft it to the correct standard.
Contact us →What a line of junction notice is
Section 1 of the Party Wall etc. Act 1996 deals with the situation where no wall currently exists at the line of junction, and the building owner wishes to build one. The Act gives the building owner two routes — a wall astride the line, or a wall wholly on their own land up to the line — and sets out how each must be notified.
Existing party walls, and works on or to them, are governed by section 2 and discussed in the party wall notice page. Excavation triggers under section 6 are discussed in the section 6 guide.
When a section 1 notice is required
The following are common situations in which a section 1 notice is required, though the list is not exhaustive — a surveyor should confirm whether your specific works fall within the Act.
- Building a new wall astride the boundary line with a neighbour, so the wall sits partly on each property.
- Building a new wall up to the boundary line, wholly within the building owner's land.
- Constructing new boundary walls where none currently exist in that form.
- Projects where a garden or outbuilding wall is being created at the junction between two titles.
How the adjoining owner may respond
On receipt of a valid section 1 notice, the adjoining owner has 14 days to respond. There are three possible outcomes.
- Consent in writing to the proposed wall as described in the notice.
- Dissent in writing, in which case surveyors must be appointed and a Party Wall Award produced.
- Do nothing within 14 days, which is treated as a deemed dispute under the Act.
Where an award is required, it is produced under the same procedure as any other party wall award.
Astride the line versus up to the line
Section 1 distinguishes between two kinds of proposed wall.
Astride the line
The wall sits partly on each property. Requires the adjoining owner's consent to proceed. If refused, the building owner can fall back to a wall up to the line.
Up to the line
The wall is built wholly on the building owner's land, right up against the boundary. The adjoining owner cannot prevent this, though they can still require the statutory process to be followed.
Common mistakes
- Serving a section 2 party wall notice when the proposed wall is new and sits at the line of junction. Section 1 is the correct route.
- Ignoring the notice requirement on boundary garden walls or outbuildings, where it still applies.
- Confusing the line of junction with the legal boundary shown on a title plan. The Act's line of junction is a physical location on the ground.
- Starting foundations before the one month notice period has expired.
- Failing to record the neighbour's existing boundary features before works start, which weakens later damage arguments.
Building a new wall at the boundary?
If your drawings show any new wall at or close to the line of junction, a section 1 notice is almost certainly required. A short review at design stage ensures the project programme absorbs the notice period cleanly rather than being held up by a late realisation.
See our party wall surveyor service or compare this page with the guides on the Party Wall Act, party wall notice, and party wall award.
Related knowledge
Compare this article with the nearest matching pages if you want to follow the topic into related surveying questions.
Plain-English guide to the Party Wall etc. Act 1996 — what the legislation covers, which works are notifiable under sections 1, 2 and 6, how the notice and award process runs, the role of the surveyor, and the consequences of proceeding without compliance.
Plain-English guide to the party wall notice under the Party Wall etc. Act 1996 — when it is required, how it must be served, statutory notice periods, and the options open to the adjoining owner on receipt.
Plain-English guide to party wall awards under the Party Wall etc. Act 1996 — when an award is required, what it contains, how it is produced by appointed surveyors, how it is appealed, and how it governs works on site.
Plain-English guide to party wall agreements under the Party Wall etc. Act 1996 — what the agreement is, when one is needed, what it contains, and the process of getting one in place through written consent or a formal Award.
Key Services
Need a surveyor rather than another article?
If this article relates to a live property issue, one of these service pages is likely to be the most useful next step.
Lease-end claims
Dilapidations
Landlord and tenant advice on schedules, quantified demands, lease interpretation, and negotiated settlement.
Explore DilapidationsNeighbourly matters
Party wall matters
Notices, adjoining owner response, schedules of condition, awards, and practical support before works start.
Explore Party wall mattersLease protection
Schedules of condition
Condition recording for lease commencement, pre-works evidence, and later protection against dispute over pre-existing condition.
Explore Schedules of condition