Lets Discuss Party Wall Matters Relating To Extensions

If you’re planning an extension, you’ve probably heard about the Party Wall Act—but do you actually need a Party Wall Agreement?

Short answer: it depends. If your extension affects a shared boundary or structure, then yes, you’ll need to serve a Party Wall Notice to your neighbour before work starts. If they agree—great! If they don’t, you may need a Party Wall Award sorted by a surveyor.

In this guide, I’ll walk you through everything you need to know about Party Wall Agreements for extensions—when you need one, what happens if your neighbour objects, and how to avoid unnecessary costs.

What is a Party Wall?

A party wall is any wall that separates two properties owned by different people. The most common example? The shared walls between semi-detached and terraced houses.

If your extension involves:

✅ Building on or near the boundary
✅ Changing a shared wall (cutting into it, removing chimney breasts, etc.)
✅ Excavating near your neighbour’s foundations

…then the Party Wall Act comes into play, and you’ll likely need to serve a Party Wall Notice.

What is the Party Wall Act & How Does it Affect My Extension?

The Party Wall Act 1996 is there to protect both you and your neighbour during construction. It ensures any work that might affect a shared boundary is done fairly and legally.

When Do You Need to Serve a Party Wall Notice?

If your extension involves any of the following, you’ll need to send a Party Wall Notice at least two months before starting work:

• Building on the boundary line (e.g., a side extension)
• Cutting into a party wall (e.g., removing a chimney breast)
• Excavating within 3m of your neighbour’s foundations (e.g., deep footings for a rear extension)

What Happens After Serving Notice?

Your neighbour has three options:

✅ They agree – No further action is needed! You can crack on with your extension.
🤝 They agree, but request a Party Wall Agreement – A surveyor will draft an official agreement.
❌ They dissent (object) – Now you’ll need a Party Wall Award, and surveyors will get involved.

💡 Tip: If your neighbour is happy to use the same surveyor as you, this will cut costs and speed up the process.

What If My Neighbour Ignores the Party Wall Notice?

If your neighbour doesn’t respond within 14 days, you must send a final notice giving them 10 more days to reply.

Still no response? You are now “in dispute.” But don’t panic! A surveyor can be appointed on their behalf to keep things moving. This way, your neighbour is still protected, but your project doesn’t get stuck in limbo.

Can You Build an Extension Without a Party Wall Agreement?

Technically, yes. But not having one is a massive risk.

Here’s what could go wrong:

🚩 Fraudulent Claims: Without an agreement, your neighbour could claim damage that wasn’t caused by your work—and you’d have no proof to dispute it.
🚩 Legal Action: Your neighbour could apply for an injunction to stop your project. This could delay your build indefinitely (and you’d have to pay their legal fees!).
🚩 Project Delays: If you don’t get the agreement sorted early, a last-minute dispute could throw your timeline out the window.

💡 A Party Wall Agreement protects you from all of this.

What is a Party Wall Award?

If your neighbour objects to your plans, a Party Wall Award is the legally binding document that settles the dispute.

A surveyor (or surveyors) will:

✅ Assess the plans
✅ Consider any risks
✅ Set out how and when the work can be done
✅ Record the condition of the neighbour’s property beforehand (so false damage claims can’t be made later!)

Once the Party Wall Award is finalised, work can legally go ahead.

What Happens If a Party Wall Dispute Arises?

Let’s say your neighbour objects to your extension and demands extra work (like strengthening their foundations).

What now?

1️⃣ Surveyor Negotiation – If you and your neighbour have different surveyors, they’ll try to agree on a fair solution.
2️⃣ Third Surveyor Involvement – If they can’t agree, a Third Surveyor is brought in to make the final decision.
3️⃣ Work Continues – Once the Party Wall Award is finalised, you can legally start building.

Costs of a Party Wall Agreement for an Extension

💡 The cheapest option? Get your neighbour to agree to one surveyor!

How to Keep Party Wall Costs Down

✅ Talk to your neighbour early – Get them on board before serving notice.
✅ Use an Agreed Surveyor – This keeps costs low.
✅ Choose a fixed-fee surveyor – No surprises! (That’s exactly what we do at Fixed Price Party Wall).

Why Choose Fixed Price Party Wall?

At Fixed Price Party Wall, we make the process simple, fair, and cost-effective.

✔ Fixed Fees – No hidden surprises!
✔ Expert Knowledge – We know the Party Wall Act inside out.
✔ Hassle-Free Process – We handle everything for you.

Need a Party Wall Agreement for your extension?

👉 Get in touch today and let’s get it sorted!