Section 1 of the Party Wall etc. Act 1996 deals with new walls at the boundary line, often called the line of junction. It is a crucial part of the Act for extensions, infill builds and other projects where a new wall is proposed at or on the boundary. Homeowners frequently assume they can simply build astride the line because it looks efficient on a drawing. In law, the position is more controlled than that. This guide explains the practical distinction between a new wall built astride the boundary and one built wholly on your own land up to the boundary, and how Section 1 usually operates in London projects.
What does “line of junction” actually mean?
The line of junction is essentially the boundary line between land in different ownership. Section 1 is engaged where the building owner proposes a new wall at that line rather than works to an existing party wall. That makes it different from the usual Section 2 party structure route and different again from Section 6 excavation procedures.
In practice, Section 1 questions often arise on side return extensions, rear extensions near the boundary, replacement boundary walls and some new-build situations. That is why Section 1 often overlaps in real life with boundary interpretation, excavation planning and neighbour communication. Our boundary wall service and rear extension Party Wall service are commonly relevant when Section 1 needs careful handling.
Section 1 issues that commonly cause confusion
Assuming a new wall can always be built astride the boundary without neighbour consent.
Confusing a new boundary wall with works to an existing party wall.
Overlooking the possibility of projecting foundations under the adjoining owner’s land.
Missing the difference between a wall astride the boundary and a wall wholly on your own land.
Treating Section 1 timing as if it were identical to all other Party Wall routes.
Failing to coordinate Section 1 issues with wider extension or excavation notices.
Astride the boundary or wholly on your own land?
Proposal
Practical meaning
Key point
Wall astride the boundary line
The new wall would sit across land in different ownership
Written consent is important; if the adjoining owner does not agree, the building owner usually cannot insist on this route.
Wall wholly on your own land up to the boundary
The new wall remains entirely within the building owner’s land
This is often the fallback route where astride-boundary consent is not given.
Notice timing and practical planning
Section 1 matters usually require one month’s notice. That sounds simple, but the design implications are often more significant than the timetable alone. If a wall has to be redesigned to sit wholly within the building owner’s land, that can affect floor area, structure, drainage and the coordination of foundations. This is one reason boundary questions should be checked early rather than after the extension layout has been fixed.
If projecting foundations are proposed or the works interface closely with excavation, separate technical and statutory considerations may also arise. For some projects, a Section 6 excavation review is needed alongside the Section 1 analysis.
Why Section 1 disputes are often avoidable
Many Section 1 disputes are not caused by hostility so much as surprise. A neighbour receives a drawing showing a wall on the boundary and feels they are being asked to give away rights or accept a design they do not understand. Good early explanation, clear plans and a realistic fallback position can make these matters much easier to manage.
If the project is likely to be neighbour-sensitive, it is often sensible to involve a specialist surveyor before the notice goes out. Hourican Associates can advise on the correct route and prepare valid notice documentation through our Party Wall notice service.
Frequently Asked Questions
It is essentially the boundary line between land in different ownership.
You should not assume so. A wall astride the boundary raises a different issue from a wall built wholly on your own land up to the boundary.
The project may need to proceed, if at all, with the new wall built wholly on the building owner’s own land instead.
Section 1 matters usually require one month’s notice.
No. Section 1 is about new building on the line of junction, not works to an existing party wall or party structure.
Yes. A boundary build can also involve excavation issues, depending on the foundations and the position of neighbouring structures.
Planning a wall at or on the boundary line?
Hourican Associates advise on boundary wall and Section 1 matters, including valid notice drafting, design implications and neighbour communication for London extensions and infill works.
General information only. The Party Wall etc. Act 1996 applies in England and Wales. This article is not legal advice and does not replace project-specific advice from a suitably qualified surveyor, structural engineer, building control professional, or solicitor where required.
Are you planning a building project – perhaps an extension, loft conversion or basement – that is on or adjacent to your property’s boundary line? Or has a ‘Party Wall’ notice dropped on the doormat informing you of a neighbour’s impending works?
It’s essential to understand all the implications of building plans. If you don’t, it could cost thousands. Our job is to ensure everything is done correctly – and that it doesn’t!
Great fast response and the party wall award was received in good time before the build. Thank you
Miguel Rios
14 May 2024
We had a party wall issue that Hourican & Associates assisted us with. They're knowledge was excellent with great communication advising us every step of the way. Very happy to have worked with them.
Katrina Pirner
02 May 2024
Richard was fantastic. He was responsive, professional, and very helpful with all the questions I had throughout the process. I can highly recommend him!
Gregg May
20 Mar 2024
Richard dealt with a lengthy and complicated set of several simultaneous party wall awards relating to our recent building project. He was professional and personable which was a great help to us in what was a difficult situation. He brought all matters to a happy conclusion for us.
Helen Booth
18 Mar 2024
It was a pleasure working with Richard of Hourican Associates. He was very professional and responsive throughout a stressful time for us. I’d have no hesitation recommending him and their services.
Jena Mihalovic
26 Feb 2024
We had the pleasure of working with Richard Hourican and his team at Hourican & Associates for our party wall agreement, and the experience was nothing short of exceptional. From start to finish, Richard exhibited a level of professionalism and expertise that surpassed our expectations.
Communication was a standout aspect of our collaboration with Hourican & Associates. Richard kept us informed every step of the way, ensuring that we were always in the loop regarding the progress of our party wall agreement. Any queries or concerns we had were promptly addressed, contributing to a seamless and transparent process.
The timeliness of their work is commendable. Unlike some experiences we've heard about, there was no unnecessary delay or dragging out of the process. Richard and his team efficiently navigated the complexities of our party wall agreement, demonstrating a commitment to meeting deadlines without compromising on the quality of their work.
In summary, if you're in need of a reliable, communicative, and efficient team to handle your party wall agreement, look no further than Hourican & Associates. Richard's professionalism and the team's dedication to client satisfaction make them a top choice in their field. We wholeheartedly recommend their services and would gladly work with them again in the future.
Robert Lines
31 Jan 2024
Hourican Associates handled a complex set of party wall agreements for us with a range of stakeholders including both leasehold and freehold owners. From our first conversation, Richard's vast knowledge of this process was evident; he explained the whole process clearly and answered all my questions thoroughly. Communication was extremely prompt the whole way through with Richard always making time to chat on the phone to keep us updated. I would highly recommend Hourican Associates.
Marwan Bateh
26 Jan 2024
The team at Hourican Associates were exceptional. They were very helpful professional in handling my party wall consents. Thank you! Highly recommend them to anyone.
Chris V
27 Nov 2023
Absolutely first class. Helpful and kind. I would very much recommend Hourican Associates.
V FitzGerald
18 Nov 2023
Richard is fantastic, understands the situation and helps sort the PWA quickly. He’s also very responsive. We have used Hourican twice now and would definitely use again.
Victoria Chapman
03 Nov 2023
Had a brilliant experience working with Richard Hourican. The service was amazing and he went above and beyond to explain everything to me and also to make sure that things were completed as soon as possible. Overall I was so extremely happy and would recommend Richard and Hourican Associates to everyone!
