Legal or procedural basis
Section 1 of the Party Wall etc. Act 1996.
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Line of Junction & New Walls
Guidance and notices for building a wall up to, or with written consent astride, the boundary line.
Service overview
What this service covers.
Extensions, outbuildings and new construction close to the legal boundary.
Section 1 deals with specified work at the line of junction. Building a new wall astride the boundary requires written consent; if consent is not given, the design may need to remain wholly on the Building Owner’s land.
When this service may be relevant
- An extension or outbuilding wall is proposed on or next to the boundary.
- The design proposes a new party wall astride the boundary.
- Foundations or special foundations may project beneath adjoining land.
Who this is for
Extensions, outbuildings and new construction close to the legal boundary.
How the instruction is approached
A clear route, matched to the facts.
The Act’s requirements and any boundary procedure depend on the actual documents, ownership and site relationships. These are the usual working stages.
- 01
Check the facts
Review the drawings, ownership interests, neighbouring structures and intended start date before deciding which notice route is relevant.
- 02
Prepare the documents
Describe the work accurately, attach the information required for that notice type and identify every owner who may need to be notified.
- 03
Serve and record
Serve the notice by an authorised method, retain evidence of service and track the statutory response and notice periods.
Questions about Line of Junction & New Walls
Useful context before you instruct.
General information only. Advice on a particular property requires the relevant documents and facts.
01Can an owner insist on building astride the boundary?
No. The adjoining owner’s written consent is needed for an astride wall. Without it, the Building Owner may have a route to build wholly on their own land, subject to the Act and other law.
02Does a Party Wall surveyor determine the legal boundary?
Not generally. If the boundary position is uncertain or disputed, separate title and boundary advice may be needed before setting out the wall.
Authoritative references
Further reading
These public sources support the general explanations on this page. They do not replace advice on the facts of a particular property.
Line of Junction & New Walls
Request an assessment or call back.
Describe the work, notice or concern and tell us which drawings or documents you already have. You do not need to decide the statutory route before contacting the team.
Call 020 8050 0443