Planning a new flank wall close to, up to, or astride your boundary line? Section 1 of the Party Wall etc. Act 1996 is the bit you need to understand.
Here’s a clear, practical explainer so you can design and programme with confidence.
Section 1 in plain English
Section 1 governs new walls at the line of junction (the boundary). There are two common scenarios you’ll see on drawings:
1) Section 1(5) — Build up to the boundary (wholly on your land)
- You can build a new flank wall up to the boundary line, provided every part of it (including footings and foundations) remains entirely on your land.
- You must serve a valid Section 1 Notice in advance.
- Typical use cases: side/rear extensions where the new wall hugs the boundary but does not cross it.
Key practicals
- Your structural design must keep foundations within your title (e.g., trench fill kept inside, or ground-bearing slab with returns designed to avoid trespass).
- You’re still entitled to Section 8 access onto the Adjoining Owner’s land if reasonably necessary to build the wall (see “Access” below). This access is controlled via an Award.
2) Section 1(2) — Build astride (on) the boundary as a new party wall
- You may propose to build a wall astride the boundary so it becomes a new party wall.
- This requires the Adjoining Owner’s written consent. If consent is refused (or not given), you cannot build astride; your fallback is a Section 1(5) wall wholly on your side.
- If there is already a party fence wall (a shared garden wall) on the line, different rights under Section 2 (works to existing party structures) will often apply. However, you still do not gain a unilateral right to place a new wall astride the boundary without consent.
Why owners sometimes refuse astride walls
- An astride wall encroaches on their land; they may prefer you to build on your side and keep control of their boundary. That’s their statutory right.
Notice, timings & drawings
- Serve the correct notice (Section 1) with accurate descriptions and clear plans that show wall alignment and foundation extents.
- Respect statutory lead-in: Section 1 Notices must be served at least one month before the planned start (plus a postal allowance if posting).
- If you’re also excavating within 3–6m deeper than the neighbour’s foundations, you’ll likely need a Section 6 Notice as well.
Access: your statutory right
Both 1(2) and 1(5) scenarios may engage Section 8 (Access):
- If access onto the Adjoining Owner’s land is reasonably necessary to build the wall (e.g., to erect a safe working platform, install temporary protection, or finish the external face), a Party Wall Award can grant time-limited, safeguarded access.
- Access isn’t open-ended; it’s strictly defined in the Award (scope, timings, protection measures, making-good).
- The Adjoining Owner cannot refuse properly awarded access under the Act, but they are protected by the Award’s conditions.
Common design & delivery pitfalls
- Foundation trespass on a 1(5) wall
- Fix: detail footings to remain on your land; show this on your structural drawings.
- Assuming astride consent
- Fix: treat 1(2) as a proposal only. If consent isn’t forthcoming, revert to 1(5) without delay to protect your programme.
- Serving only one notice when two apply
- Fix: if you’re both building at the boundary and excavating deeper/nearby, serve Section 1 and Section 6 Notices.
- Vague access requests
- Fix: explain why access is needed, how long for, and what protections you’ll install. Awards move faster when specifics are clear.
- Late service
- Fix: serve early. If dissent arises, surveyor appointments and an Award will take time—especially on engineered schemes.
Quick examples
- Single-storey side extension with a wall tight to boundary:
Section 1(5) notice (wall wholly on your land). If excavating within 3–6m deeper than neighbour’s foundations, add Section 6. Access likely via Award. - Joint party wall proposal for a shared new boundary wall:
Section 1(2) notice seeking consent. If refused, default to 1(5). If a party fence wall already exists, relevant Section 2 rights may apply for alteration/rebuild—but there is still no unilateral right to place a new wall astride the boundary without consent.
Make Section 1 Simple
Need certainty before you lock your drawings?
Email team@simplesurvey.co.uk for a free plan check (we’ll confirm which notices apply and outline the cleanest route to an Award).
Simple Survey — Fixed Nationwide Fees (RICS-Qualified)
| Service | What’s included | Fixed price* |
|---|---|---|
| Party Wall Notice (per Adjoining Owner) | Drafting, validity checks, correct service & response tracking | £25 |
| Agreed Surveyor Award | Single impartial surveyor; tailored protections; service of Award | from £300 |
| Building Owner’s Surveyor (two-surveyor route) | Liaison, protections, drafting & service of Award | from £325 |
*Complex foundations/deep excavations may require additional specialist input. We’ll flag this up-front—no surprises.
Nationwide • Fixed fees • RICS-qualified • Basement/loft/extension specialists
FAQ
Q1: If my neighbour refuses an astride wall under 1(2), can I insist?
No. An astride wall needs the Adjoining Owner’s written consent. Without it, your lawful route is a 1(5) wall wholly on your land (with access as awarded if needed).
Q2: We already have a brick garden wall on the line. Does that change things?
Possibly. An existing party fence wall brings Section 2 (works to existing party structures) into play. You’ll still need proper notice and, where relevant, an Award—but you do not gain a unilateral right to plant a new wall astride without consent.
Q3: Can I get access if I’m building a 1(5) wall on my side only?
Yes—if access is reasonably necessary to do the notifiable works, Section 8 access can be awarded (with safeguards and defined timings).
Q4: Do I need both Section 1 and Section 6 notices?
Often, yes. Section 1 covers the new wall at the boundary. Section 6 covers adjacent excavation within 3–6m deeper than your neighbour’s foundations. Many extensions trigger both.
Q5: How soon should I serve Section 1 notices?
At least one month before works (plus postal allowance). If dissent/awards are likely, serve earlier to avoid programme slippage.
Have drawings ready and want a sanity check?
team@simplesurvey.co.uk — fast, friendly, and RICS-qualified.