The short answer
Yes. Taking out a chimney breast always needs building control approval, since the breast forms part of the structure. The stack above it, and the load it carries, must be supported or taken down properly. Speak to your building control body before work begins, and serve a party wall notice if the breast is on a party wall.
What approval is needed to take out a chimney breast, how the stack above is dealt with, and what changes when the breast is shared.
Why approval is always needed
The breast is the section of chimney standing proud of the room wall, rising from the fireplace through each floor. It looks like a boxed-in lump of wall, but it is built into the house and carries load. The Planning Portal's guidance on removing chimney breasts says approval always applies for that reason: they belong to the structure.
This is a firm rule and not a matter of how big the breast is. A single-storey breast in a small bedroom needs the same approval as a double-height one in a living room. Taking a breast out without it risks an unsafe structure and a problem when you come to sell, since a buyer's solicitor can ask to see the completion certificate.
Approval comes from building control. In Crawley the local authority service is Crawley Building Control. For other places, the council's own team deals with it, or a registered building control approver, the private route that has existed alongside councils for years and has been under a registration regime since April 2024. Our answer on permission to remove a chimney explains how that differs from planning permission, which is a separate check.
Always ask before any bricks are touched.
What happens to the stack above
When the breast is removed from a room, whatever sat on top of it must be held up another way. That may be the rest of the breast on the floor above, the chimney stack through the loft, or the stack above the roof, with its pots and flaunching, which weighs a good deal.
There are two broad routes. In one, the stack is taken down to below the roof line and the roof is made good, which removes the load but leaves a patch of roof to repair. In the other, the stack stays and is supported, often by steel such as a beam or a bracket fitted by a builder under the direction of a structural engineer or building control. Which suits you depends on the house.
An engineer or building control surveyor decides the support, not the roofer, and it must be in place before the breast comes out. We deal with the roof end: the stack above the roof, the flashing, the flaunching and the weatherproofing when a stack is lowered or taken away. Our guide to chimney stack removal describes that work.
Checkatrade's October 2026 table lists stack removal at £260 to £340 per metre, with a breast removal where the stack stays at around £2,500. Treat both as national yardsticks.
A breast shared with the neighbour
In semis and terraces the breast often sits against the party wall, serving fireplaces on both sides. Removing your half cannot be treated as a private job in that case. The stack above is shared in effect, and cutting it away is work the Party Wall etc. Act 1996 covers, which requires written notice to the neighbour at least two months ahead.
Speak to the neighbour well before you plan anything. Ask whether they use their fire and whether they have altered their own breast. Our answer on the Party Wall Act and roof work explains when notice applies, and our answer on who repairs a shared chimney stack covers cost.
The neighbour may already have removed their breast, leaving the stack above resting on yours, or the reverse. Look in the loft to see what the stack is sitting on, and tell the building control surveyor what you find.
Do not assume a missing breast next door means yours can go. Each case needs its own check by a structural engineer or surveyor. If your neighbour's fireplace still works, your half of the flue must not be left open to theirs.
Order of work and what to ask
Plan the job in the right order. Contact building control first and agree what drawings or calculations they want. Then arrange the structural support, remove the breast, and deal with the roof end. If the stack above the roof is coming off, the roofer should be involved from the start, so the roof is weathertight as soon as it is opened.
Ask each tradesperson a few direct questions. Who is getting the approval, and who holds the certificate? Who designs the support? What happens to the flue and pots? And does the written price include scaffolding, making good the roof and taking the rubble away?
A single written price from the roofer should cover the stack end only, with the building work priced by the builder. We survey first, share photos of the stack and the loft, and give one written total, and we are happy to work alongside your builder and engineer.
If the stack is staying and only needs repair, our chimney repairs page covers that,.
More on this in Chimney Repairs in Crawley
Two more breast removal questions
Can I take out the breast but keep the stack on the roof?
Sometimes. The stack must then be carried by steelwork or another support designed for the load, and the design needs approval. It is a larger job than removing both, so it is worth pricing each route. A structural engineer or your building control surveyor will say whether keeping the stack is practical.
Do I need approval if I only remove the breast in the loft?
Yes, the same rule applies. The loft section carries the stack above it, so removing it changes the support in just the same way. Tell your building control body what you plan, and let them decide what information they need. Do not start on the basis that a hidden section is exempt.