Chimney Breast Removal: Cost, Rules & Process (2026)

Key Takeaways

Removing a chimney breast frees up valuable space in tight London rooms.
The chimney above must be supported, usually with gallows brackets or a steel beam.
It requires a structural engineer and Building Control sign-off.
Often a party wall matter, as chimney stacks are usually shared.
Typical cost is £1,500 to £4,000+ depending on extent and support method.

A chimney breast can eat up valuable floor space in a tight London room, and removing it is a popular way to reclaim it. But it is structural work that must be done properly. Here is the cost, the rules and the process.

Why remove it?

In a compact London bedroom or reception room, a redundant chimney breast projects into the room and limits how furniture and fittings can be arranged. Removing it reclaims that space and squares off the room, which is why it is such a common request in renovations.

It must be supported

The crucial point is that a chimney breast holds up the chimney stack above it. Remove the lower section and the upper part must be carried by new support, usually steel gallows brackets bolted to the party wall, or a steel beam. This must be designed by a structural engineer and signed off by Building Control. It is never a simple knock-out job.

Cost

Scope	Typical cost
One floor, gallows bracket support	£1,500 to £2,500
Multiple floors	£2,500 to £4,000
Full stack removal	£4,000+

Building Control and party wall

The work needs Building Regulations approval, and because chimney stacks are usually built into the shared party wall in terraces and semis, the Party Wall Act normally applies, so notice must be served. We manage the engineering, building control and party wall process. For a free quote, contact us or call 07472 424 226.

The GS Renovation Team

GS Renovation & Home Improvements has delivered kitchen, bathroom, structural and extension projects across London for over 30 years. This guide reflects current UK industry pricing and our hands-on site experience.

Frequently Asked Questions

How much does it cost to remove a chimney breast?

Removing a chimney breast typically costs £1,500 to £4,000 or more, depending on how much you remove (one floor or the full height), the support method, access and making good. Removing the breast on one floor and supporting the chimney above with gallows brackets is at the lower end; full removal of the entire stack costs more.

Do I need permission to remove a chimney breast?

You need Building Regulations approval, because the structure above must be properly supported, but you do not normally need planning permission for internal removal. If the chimney is shared with a neighbour, which is common in terraces, the Party Wall Act also applies and notice must be served.

Can you remove a chimney breast on one floor only?

Yes, but the chimney breast and stack remaining above must be supported, because you are removing what held it up. This is usually done with steel gallows brackets bolted to the party wall, or a steel beam, all designed by a structural engineer. You cannot simply remove the lower section and leave the upper unsupported.

Is a chimney breast load-bearing?

A chimney breast supports its own weight and the chimney stack above, and sometimes floor or roof loads. Removing it therefore always requires structural support for what remains, designed by a structural engineer and signed off by Building Control. It should never be removed without calculations.

Do I need a party wall agreement to remove a chimney breast?

Usually, yes, in a terraced or semi-detached home, because chimney stacks are typically built into the shared party wall. Removing the breast or fixing gallows brackets affects that wall, so the Party Wall Act applies and you must serve notice on the affected neighbour.

Chimney Breast Removal