Removing a Chimney Breast: Why You Need a Party Wall Agreement

Thinking of knocking out a chimney breast to make a room bigger? It might seem like a simple DIY job—sledgehammer, rubble bags, a bit of plaster, and boom, extra space.

But hold up. It’s not that easy. Chimney breasts are structural, meaning if you remove one without the right support, you could be compromising your house’s stability—or worse, your neighbour’s house too!

And here’s the kicker… if it’s on a shared wall, you’ll need a Party Wall Agreement before you can even start.

Let’s break it down.

How Easy Is It to Remove a Chimney Breast?

In short? Not very.

A chimney breast isn’t just a decorative feature—it’s part of the building’s structure. If you take out the ground floor chimney breast, you’ll have several tonnes of masonry above it (first floor, attic, and chimney stack). And that all needs proper support.

Think of it like removing the bottom of a Jenga tower—without proper reinforcement, the whole lot could come crashing down.

Why You Shouldn’t DIY This Job

Technically, you could take a sledgehammer to it, but here’s what could go wrong:

🚩 Bricks become loose – You might damage your neighbour’s property.
🚩 Chimney collapse risk – If the remaining chimney isn’t supported, it could fall.
🚩 Legal & resale issues – A surveyor will spot dodgy work when you try to sell.

💡 Bottom line: Get professional help. This is not a DIY project!

How to Remove a Chimney Breast Properly

Here’s how a professional will handle it:

1️⃣ Remove the chimney breast carefully – Usually done by hand to minimise vibration and prevent bricks coming loose on your neighbour’s side.
2️⃣ Provide structural support – Typically, a steel beam is installed to support the weight of the remaining chimney. In some cases, gallows brackets might be used (but only with Building Control approval).
3️⃣ Get structural calculations – A structural engineer will need to design the support system to comply with building regulations.

❌ What NOT to do:

• Rest the chimney on timber nailed to joists (yep, we’ve seen this before!)
• Use a metal plate across the joists
• Hope for the best and just leave it unsupported

💡 Pro tip: Before starting, check with Building Control in your area to make sure your support method is approved.

Do I Need Building Control Approval to Remove a Chimney Breast?

Yes! Because this is structural work, you’ll need building regulation approval.

If you don’t get approval, you could run into major problems when selling your house. A buyer’s solicitor will check for consent—and if you haven’t got it, you’ll need to either:

✔ Apply for retrospective approval (which may require opening up ceilings/walls to prove the work was done safely).
❌ Or put things right—which could cost thousands!

💡 Tip: Always get the proper approvals before starting work. It’ll save you a massive headache later.

Do I Need a Party Wall Agreement to Remove a Chimney Breast?

If the chimney breast is on a shared or party wall, then yes, you will need a Party Wall Agreement.

Why?

Because removing a chimney breast affects the structural integrity of the shared wall. The last thing you want is for bricks to come loose and cause damage to your neighbour’s home—or worse, collapse their chimney entirely.

When Do I Need to Serve a Party Wall Notice?

Under the Party Wall etc. Act 1996, you must serve a Party Wall Notice at least two months before starting work if:

• The chimney breast is on a shared wall (e.g., in a semi-detached or terraced house).
• The work involves cutting into the party wall (to install support beams).
• The chimney removal could affect the neighbour’s structure.

👉 Not sure if you need an agreement? Check out our guide: Do I Need a Party Wall Agreement?

What If I Live in a Flat?

🚨 Removing a chimney breast in a flat is even more complicated.

• If there are flats above or below you, you’ll need to serve notice on all affected neighbours.
• You’ll also need permission from the freeholder.
• If your removal affects their ability to use their chimney (e.g., they want a log burner in the future), they might object—and there’s very little you can do about it.

💡 If you live in a flat, get legal advice first before making any plans.

What Should I Include in My Party Wall Notice?

The Party Wall Act sets out exactly what needs to be in a notice. A quick chat with your neighbour does not count—you must put it in writing.

A Section 3 Party Structure Notice is needed, which should include:

✔ Your name and address
✔ The address of the property where work will happen
✔ A full description of the work (including plans if possible)
✔ The start date (minimum 2 months after notice)
✔ A statement that the work is being done under Section 2 of the Party Wall Act

💡 Need a template? We provide free Party Wall Notice templates—get in touch, and we’ll send one over!

What If My Neighbour Objects?

If your neighbour doesn’t consent, you’ll need a Party Wall Surveyor to resolve the dispute.

Here’s what happens next:

1️⃣ They appoint their own surveyor, or agree to use yours.
2️⃣ The surveyor(s) agree on a fair approach (e.g., ensuring your work doesn’t weaken their wall).
3️⃣ A Party Wall Award is issued, allowing work to go ahead.

💡 The cheapest option? Get them to use the same surveyor as you!

👉 Check out our Fixed Fee Party Wall Service to keep costs low.

Can I Remove the Whole Chimney Stack If My Neighbour Doesn’t Use It?

Only if they give written permission.

Even if they don’t use their chimney, they don’t have to agree to its removal. If they refuse, you’ll have to leave their part intact.

And if they do agree? You’ll likely be responsible for making good their roof once the stack is removed.

Final Thoughts

Removing a chimney breast isn’t just about swinging a sledgehammer—it’s a serious structural job.

✅ Get Building Control approval so your work is legal.
✅ Serve a Party Wall Notice if it’s on a shared wall.
✅ Use a professional surveyor to keep things safe and compliant.

💡 Need a Party Wall Agreement?

👉 Contact Fixed Price Party Wall today—we’ll make the process simple and stress-free!