Boundary Disputes: When the Neighbour Says You've Built on Their Land

SiteKiln gives you plain-English information, not legal advice. Boundary disputes are land law -- if one blows up on your job, your client needs a solicitor and a surveyor, not a builder's opinion.

‍‌​​‌‌‌​​‌​​​​‌​‌‌​‌‌​​‌​​‌‌​​‌​‍# Boundary Disputes, When the Neighbour Says You've Built on Their Land

Short answer: it's your client's land problem, but if you keep building once the row starts, you can get dragged into an expensive mess. Your job is to spot trouble early, freeze the work, and get the owners and their surveyors talking.

1. What a boundary dispute actually is

On a domestic job, a boundary dispute usually starts when:

• You put in foundations, a fence, a wall or a driveway near the edge of the plot
• A neighbour says "that's on my land" or "you've moved the boundary"

Legally, the boundary between two properties is where the legal titles say it is, not where the latest fence or hedge happens to be. But:

• HM Land Registry title plans show "general boundaries" only
• Under the general boundaries rule (Land Registration Act 2002, s60), the red line on the plan is approximate, not a precise surveyed line
• The true boundary can be slightly inside or outside that red line, depending on old deeds, physical features and historic agreements

So waving a title plan and saying "look, the red line" doesn't actually settle the argument.

You usually need:

• The title plans and, if they exist, old paper deeds with measurements or descriptions
• A look at what's on the ground -- fences, walls, ditches, hedges
• Sometimes, a measured survey and a specialist boundary surveyor to piece it together

2. Where your responsibility starts and stops

You are generally not the landowner. You're the builder doing what you've been told.

If you build something that turns out to be over the line:

• The core dispute is between the two neighbours -- your client and the person next door
• The neighbour's claim is usually against your client as the owner, for trespass or to move/alter the encroaching structure

Could they come after you?

In law, trespass is entering or placing things on someone else's land without permission. If you knowingly put foundations, walls or fences on their land, that's technically your trespass too.

In practice, neighbours usually sue the landowner, who may then come after you under your contract if they say you ignored instructions or were negligent.

The key word is knowingly:

• If you bulldoze on the neighbour's side after they've clearly objected, and you "crack on" regardless, a court can treat that as deliberate or reckless trespass and take a dim view
• If you stop when the complaint arises and tell both parties to sort the boundary, you're in a far safer position

Plain version: it's mainly the client's problem, until you ignore red flags -- then it can become yours too.

3. Before you start near a boundary -- how to stay out of trouble

You can save yourself a lot of grief with a 10-minute pre-start routine:

Check the title plan. Ask the client for their Land Registry title plan and any old deeds. Use them to get a rough idea, not an exact line -- remember "general boundaries" only.

Walk the boundary. Look for fences, walls, hedges, pegs, manholes. Note anything weird -- double fences, dog-legs, "extra" strips of garden, physical features that don't match the red line.

Ask about history. "Have you and next door ever had issues about this fence or this strip of land?" If there's history, treat the job as high-risk and advise the client to get a boundary surveyor involved before you dig.

Document the starting position. Take photos of the boundary from multiple angles before you touch it. If you're building tight to the line, mark out and photograph the proposed line relative to existing features.

Party Wall vs boundary. If you're building on or near a shared wall or excavating next to the neighbour's foundations, that's a Party Wall etc. Act 1996 issue -- notices, surveyors, awards. A boundary dispute is about who owns what land, not about movement or damage risk -- different law, different process.

If your gut says "this is tight" or "the neighbour already hates them", advise your client to talk to a RICS surveyor or solicitor before you become the meat in the sandwich.

4. When the neighbour says "you're on my land"

If you're mid-job and the neighbour kicks off:

Stop work at the boundary line. Don't pour concrete, don't lay another course, don't sink posts closer to the disputed line. Carry on with other parts of the job away from the argument if you safely can.

Don't take sides. You're not the judge. Say: "This is between you two as owners -- I need you and my client to agree the boundary before I continue."

Tell your client immediately. Explain the risk: if you carry on and it is over the line, they could face an order to alter or demolish at their cost, and you may be dragged in.

Don't move existing markers. Don't pull out fences, pegs or walls that look like they're part of the current boundary unless both neighbours have clearly agreed in writing.

Record everything. Photos of the area, any old markers, and any notes or emails about what was agreed. Note down what the neighbour said, and what instructions your client gave you.

If the client says "just build it there, I'll deal with them": make it clear in writing that there is a boundary objection and that you advise stopping until the boundary is resolved. If they still insist, you need to think hard about whether you want to be part of it -- at that point it's not "accidental" any more.

5. Trespass, remedies and how bad this can get

Building over someone's boundary is usually a civil trespass to land.

Neighbour remedies include:

• Injunctions -- court orders to stop further work or to remove or cut back what crosses the boundary
• Damages -- compensation for the loss of land or nuisance; in some cases payment to keep the encroachment
• In rare cases, claims about overhead cranes, scaffolds or oversailing can also be trespass, needing specific agreements

Courts can and do order developers to reduce or alter buildings that cross the line, especially where the encroachment is significant and not truly accidental.

From your perspective: you're unlikely to be the first name on the claim form, but you could be joined by your client if they say you went outside instructions, or facing a claim under your PI/PL if your design or setting-out was negligent.

This is why stopping and telling the owners to sort it is the safest move.

6. Boundary vs Party Wall -- don't mix them up

It's easy for clients (and some builders) to mash these together, but they're different:

Boundary dispute: "Whose land is this line on?" Driven by title plans, old deeds, what's on the ground, and sometimes adverse possession (long-term occupation).

Party Wall etc. Act 1996: applies when you work on a shared wall/structure or excavate near neighbouring foundations. It's about structural movement, access and damage, not ownership of land. Needs formal party wall notices, possible surveyors, and an award.

You can have both at once -- e.g. arguing whose wall it is, and at the same time needing party wall procedures if you're touching it -- but the legal routes are different.

7. Adverse possession -- when "we've always used that bit" matters

Adverse possession (often called "squatter's rights") can crop up in boundary rows:

• If someone has treated land as their own for many years -- fenced it, gardened it, used it exclusively -- they may claim title by adverse possession
• For registered land after the Land Registration Act 2002, they normally need 10 years of such occupation and must apply to Land Registry; the neighbour is notified and can object

You don't need to become an expert, but you should know:

• Long-standing fences and use might not match the red line -- and that can change who actually owns that strip
• If a neighbour hints at "we've had that bit for 20 years", that's a sign your client needs legal and surveyor advice, not DIY boundary setting

Again, it's a landowner problem -- but you don't want to be digging or building while that argument runs.

8. Bringing in surveyors and staying out of court

Boundary court fights are expensive, slow and miserable. It's common to see £5k-£50k+ in legal and expert fees and 1-2 years of stress over a strip you couldn't park a wheelbarrow on.

Better routes:

RICS boundary dispute services. RICS run boundary dispute mediation services -- you get an independent mediator/surveyor to help both sides agree a line. It's informal, faster and much cheaper than court.

Measured survey and expert report. A RICS surveyor can do a measured survey, compare it to the title plan and deeds, and produce a report that often helps settle things.

Mediation. Even outside RICS schemes, boundary disputes are ideal for mediation -- you're balancing slivers of land and relationship, not massive damages.

Your role: suggest your client gets a surveyor and a solicitor if the dispute isn't trivial. Make clear you'll wait for their joint instruction once they've agreed where the line is.

9. Practical builder rules when a boundary row appears

In simple terms:

• Don't move the line -- don't shift fences, walls or pegs off your own back
• Don't play lawyer -- don't tell one side they're right and the other is wrong
• Do stop work near the disputed boundary until it's resolved
• Do protect your own position -- photos, emails, notes of what you were told

If a neighbour is aggressive or starts interfering with your work or kit: stay calm, don't respond in kind. Let your client and, if needed, the police handle any safety issues.

Remember, you're contracted to the client, not the neighbour -- they're the ones who must take the legal lead.

What to do next

• Before starting near a boundary: run through the pre-start routine in section 3 -- it takes 10 minutes and could save you months
• If a neighbour has objected: stop work at the boundary, tell your client, and put your advice in writing (section 4)
• Read the Party Wall Act guide if you're working on or near a shared wall -- boundary and party wall issues often overlap
• Read the mediation guide -- boundary disputes are prime candidates for mediation rather than court
• Download from the Doc Hub: the Neighbour Notification Letter template

Boundary dispute solicitors typically charge £250-400/hour. A surveyor report costs £500-2,000. This guide is free. If SiteKiln helped, buy us a brew.

Sources

• Land Registration Act 2002, Section 60 -- legislation.gov.uk/ukpga/2002/9 -- general boundaries rule
• Party Wall etc. Act 1996 -- legislation.gov.uk/ukpga/1996/40 -- duties when working on or near party walls (separate from boundary ownership)
• Land Registration Act 2002, Schedule 6 -- adverse possession for registered land
• HM Land Registry Practice Guide 40 -- Land Registry plans and the general boundaries rule
• RICS Professional Standards: Boundaries -- guidance on boundary surveying and dispute resolution

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