The short answer
A structural engineer for a chimney breast removal in the UK typically costs around £250–£600, because it is usually a single, well-defined calculation rather than a full design package. The engineer designs how to support the chimney that remains above — commonly gallows brackets bolted to the party wall, or a steel beam where the brickwork above is heavy or the wall cannot take brackets. A removal across two floors or one that takes out a load-bearing chimney needs more design and sits higher, often £400–£800. The fee buys the calculations and a sketch that Building Control needs under Part A. A site visit, if required to check the existing brickwork, may add £150–£300. The honest figure depends on how much chimney is left to support and what it bears on.
Removing part of a chimney leaves brickwork above that was previously carried by the part you take out, so the remaining stack must be supported by design — not guesswork. The figures below are typical ranges for guidance, not quotations.
Typical UK chimney fees
- Single-floor breast removal£250–£500
- Two-floor removal£400–£800
- Gallows bracket designcommon solution
- Site visit (if needed)£150–£300
- Building Controlcalculations required
Why the remaining stack must be supported
When you remove a chimney breast on the ground or first floor but leave the stack and chimney above, that upper masonry loses the support it was sitting on. The engineer's job is to design a replacement support so the remaining chimney does not crack, drop or pull away. The two usual solutions are gallows brackets — steel brackets bolted into the party wall to carry the stack — or a steel beam spanning to pick up the load where brackets are not suitable. Removing the chimney completely, from base to roof, removes that problem but is a bigger job and may affect a neighbour's shared stack.
- Gallows brackets: common where the party wall is sound brickwork.
- Support beam (RSJ): used where loads are heavy or brackets unsuitable.
- Full removal: avoids supporting the stack but is more disruptive.
- Calculations and sketch for Building Control under Part A.
What moves the price
Chimney removal design is usually a small, focused piece of work, which is why the fee is lower than for an extension or loft. The number rises when more chimney is removed (across two floors rather than one), when the brickwork above is heavy, or when the engineer has to attend site to confirm the wall can take gallows brackets. A shared stack on a party wall can also add a Party Wall Act notice — a separate cost.
| Scope | Typical engineer fee | Notes |
|---|---|---|
| Ground-floor breast only | £250–£500 | often gallows brackets |
| First-floor breast | £300–£550 | support for stack above |
| Both floors | £400–£800 | more load to support |
| Site visit (if needed) | £150–£300 | checks existing brickwork |
Indicative UK figures for guidance. Sources: Checkatrade structural engineer cost guide; typical 2025/2026 ranges.
Building Control and party walls
Removing a chimney breast is notifiable to Building Control because it alters how the building carries load. The engineer's calculations are submitted as part of the Building Regulations application under Part A (structure), and Building Control will want to see how the remaining stack is supported. Where the chimney sits on a party wall shared with a neighbour — very common in terraces and semis — you usually also need to serve notice under the Party Wall Act 1996, because gallows brackets bolt into that shared wall. That is a separate surveyor matter, but the engineer's design feeds into it.
Where chimney removal fits the wider budget
The structural engineer is one line in the total chimney removal cost, alongside the builder who does the work, any scaffolding for stack access, making good the roof and walls, and the Building Control fee itself. Because the engineering is a small, defined task, it is almost always quoted as a fixed fee rather than hourly. If you are removing the breast on more than one floor, or if the property is older with soft lime mortar, expect the engineer to want a site visit before finalising the design — soft or perished brickwork changes which support method is safe.
Full removal versus partial removal
There are two broad ways to deal with a chimney, and they carry different engineering and cost implications. Partial removal takes out the breast on one or more floors but leaves the stack and chimney above — this is the option that needs gallows brackets or a beam to support the masonry left in place, and it is usually chosen to free up internal space while keeping the external roofline intact. Full removal takes the chimney down from the base right through the roof; it avoids having to support a remaining stack, but it is a larger, more disruptive job involving roof works, weatherproofing where the stack passed through, and often scaffolding. On a shared stack in a terrace or semi, full removal also affects your neighbour's flue, so it cannot be done unilaterally. The engineer will advise which approach suits your property, and the choice has a bigger effect on the overall cost than the engineering fee itself.
- Partial removal: needs designed support for the stack above; keeps the roofline.
- Full removal: no stack to support, but roof works and weatherproofing add cost.
- Shared stack: full removal affects a neighbour's flue and needs agreement.
- Engineer's role: advises the safe method and designs any support needed.
Frequently asked questions
Do I need a structural engineer to remove a chimney breast?
Yes. Removing a chimney breast changes how the remaining stack is supported, so Building Control requires structural calculations from a competent engineer showing how the masonry above will be held up, usually with gallows brackets or a beam.
What are gallows brackets?
Gallows brackets are steel brackets bolted into the party wall to carry the weight of a chimney stack after the breast below has been removed. They are a common, economical solution where the wall is sound, designed and sized by the structural engineer.
Is removing a chimney breast a party wall matter?
Often, yes. If the chimney sits on a wall shared with a neighbour and you fix gallows brackets into it, the Party Wall Act 1996 usually applies and you should serve notice. This is separate from the structural engineer's fee.
Sources & further reading
- Checkatrade — structural engineer cost guide
- GOV.UK — Party Wall etc. Act 1996 explanatory booklet
- IStructE — find a chartered structural engineer
Figures on this page are typical UK ranges drawn from published sources and depend on your specific project. They are guidance, not a quotation.