The short answer
Yes — in almost every case you need a chartered structural engineer to remove a chimney breast. Taking out the breast on the ground or first floor leaves a heavy section of chimney stack and brickwork above it that was previously carried straight down to the foundation. That load has to be redirected, normally onto gallows brackets bolted to the party or flank wall, or a steel beam. The engineer produces structural calculations proving the support and the wall it fixes to can take the weight, and the work is notifiable under Part A of the Building Regulations, so Building Control must inspect and sign it off. Removing the whole stack from roof to floor is simpler structurally but still usually needs an engineer to confirm nothing above is left unsupported.
A chimney breast looks like a feature you can just knock out, but the brickwork it carries is real weight. The engineer's job is to prove the leftover masonry will not drop. Here is what is actually involved and where the cost goes.
Chimney breast removal
- Engineer neededYes — almost always
- Typical supportGallows brackets or steel beam
- Building RegsNotifiable under Part A
- Engineer fee£300–£700 for calcs
- Party Wall ActOften applies on shared wall
Why a chimney breast cannot just be knocked out
A chimney breast is the projecting column of brickwork that houses the flue. In a typical terraced or semi-detached house it runs from the ground floor up through the bedrooms and into the roof space, where it becomes the stack you see above the roofline. When you remove the breast on a lower floor, everything above it — often a tonne or more of brick, plus the stack itself — loses its direct path to the ground.
That remaining masonry has to be caught and carried back onto something solid. The two standard solutions are gallows brackets (steel angle brackets bolted to the party or flank wall that cantilever out to support the breast above) and a steel beam spanning between walls. Which one suits your house depends on how much weight sits above, the condition and thickness of the supporting wall, and whether your neighbour's chimney shares the same wall. The engineer makes that call and sizes the support.
What the engineer actually produces
For a chimney breast removal the engineer visits or works from your measurements, then prepares structural calculations covering the load above, the chosen support method, and the fixings or padstones needed. The pack is what Building Control checks before signing off the work. It typically includes the bracket or beam specification, the bolt sizes and spacing, and a note on how the masonry above is to be tied and made good.
- Calculations proving the gallows brackets or beam carry the load with the required safety margin.
- A sketch or detail showing the support arrangement and fixings.
- Specification of the steel, brackets, bolts and any padstones.
- Guidance on temporary support (acrow props and needles) while the breast is taken down.
Engineer fees for a single chimney breast are commonly £300–£700 for the calculations, rising if multiple breasts or floors are involved or a full site visit and report is needed.
Building Control, party walls and the build itself
Removing a chimney breast is notifiable work under Part A (structure) of the Building Regulations. You submit a building notice or full plans application to your local authority Building Control or a private approved inspector, pay the fee, and an inspector visits at key stages — typically once the support is installed and again on completion before issuing a completion certificate. Skipping this leaves you without the certificate a buyer's solicitor will ask for later.
Where the chimney sits on a shared (party) wall between you and a neighbour — common in terraces and semis — the Party Wall etc. Act 1996 usually applies, because you are cutting into or fixing brackets to a wall you share. You normally have to serve a party wall notice on the neighbour before work starts. Many homeowners overlook this and only discover it when a dispute or a later house sale brings it up.
| Item | Typical UK figure | Notes |
|---|---|---|
| Engineer calculations | £300–£700 | single breast, one floor |
| Building Control fee | £300–£500 | building notice / approval |
| Removal & making good | £1,500–£3,500 | labour, beam/brackets, plaster |
| Party wall notice | £0 self-served | surveyor fees if dispute |
Indicative UK figures for guidance, 2025–2026. Sources: HomeOwners Alliance and Checkatrade cost guides; gov.uk Building Regulations.
When you might not need full engineering input
There is one case that is structurally simpler: removing the whole chimney from roof to floor, including the stack. If nothing is left hanging above, you are not redirecting load mid-height, so the structural challenge is smaller. Even then, an engineer should confirm the roof and any remaining masonry are not relying on the chimney for lateral stability, and you must make the roof watertight and weatherproof where the stack passed through. Removing only a flue gathering or fire surround that carries no masonry above it may not be structural at all. The safe rule is: if any brickwork sits above what you are taking out, treat it as structural and get the calculations — the cost of an engineer is small against the cost of a sagging bedroom floor or a refused completion certificate.
One detail that catches people out is that chimney breasts are often removed on one floor at a time over the years, by different owners, without anyone keeping the paperwork. A previous occupier may have taken out the ground-floor breast and left the one above, or vice versa, and the support they used (if any) may be unknown. If you are buying or already own a house where a breast has clearly been removed but there is no completion certificate or engineer's calculation on file, it is worth having an engineer inspect what is actually holding the remaining masonry up — occasionally they find a breast left sitting on nothing more than the lath-and-plaster of the floor below, which is precisely the hidden danger this work exists to prevent. Where you are removing a breast yourself, keep the engineer's calculation and the Building Control completion certificate together with your house papers, because the next owner's surveyor will look for exactly that evidence, and a documented, signed-off removal is worth far more at sale than an undocumented one that raises a red flag.
Frequently asked questions
Can I remove a chimney breast without a structural engineer?
Not safely or legally where masonry remains above. The work is notifiable under Part A of the Building Regulations and Building Control will want to see structural calculations for the gallows brackets or beam supporting the chimney above. Doing it without them risks a refused completion certificate and a dangerous structure.
What are gallows brackets?
Gallows brackets are steel angle brackets bolted to a solid party or flank wall that cantilever outwards to catch and support the chimney breast left above after you remove the lower section. They are a common, economical solution but are only accepted by Building Control where the supporting wall is sound and thick enough.
Does the Party Wall Act apply to chimney breast removal?
Usually yes, where the chimney is on a wall shared with a neighbour. Cutting into or fixing brackets to a party wall is notifiable work under the Party Wall etc. Act 1996, so you should serve a party wall notice on the affected neighbour before starting.
Sources & further reading
- HomeOwners Alliance — chimney breast removal
- Planning Portal — Building Regulations
- gov.uk — Party Wall etc. Act 1996 explanatory booklet
Figures on this page are typical UK ranges drawn from published sources and depend on your specific project. They are guidance, not a quotation.