Removing a chimney breast: building regulations, support and the paperwork
The breast is the easy part. What holds up the chimney above it is what building control cares about.
Removing a chimney breast is structural work, and the Planning Portal says building regulations approval always applies. Whatever is left above has to be properly supported, usually on a steel beam or gallows brackets designed for the load. If the breast is in a wall you share with next door, the Party Wall Act requires two months’ notice.
The short version
- Make the building control application before anyone touches a brick. Taking the breast out without support for the stack above is the classic way a chimney ends up hanging off the wall.
- Gallows brackets are not automatically accepted. Some councils now accept them only with an engineer’s calculation and pull-out tests, and not at all where next door’s breast is already on brackets. Ask your building control team which they will accept before you get quotes.
- On a party wall, serve a party structure notice at least two months before work starts.
- Any gas fire or boiler using the flue should be disconnected by a Gas Safe registered engineer first. Nobody working in the course of a business can legally do that unless they are registered.
- Keep the completion certificate. Without it, a buyer’s solicitor may treat the work as unapproved.
Building regulations
Why a chimney breast needs approval when an internal wall might not
A chimney breast is the bottom of a column of brickwork that runs up through every floor and out through the roof. Take it out of a ground floor room and the brickwork above has nothing under it.
That is why the work counts as building work in law. Under regulation 3 of the Building Regulations 2010, a material alteration is building work, and an alteration is material if at any stage it would leave a building not complying with a relevant requirement where previously it did. The first requirement on the list is Part A, structure.
The Planning Portal is plain about it: building regulations approval will always apply when removing chimney breasts, because they are part of the building’s structure, and it advises getting a structural engineer to provide drawings and calculations for the application. Planning permission is a different matter. It is not needed to remove an internal chimney breast, because the outside of the house does not change. The exceptions are a listed building, which needs listed building consent, and taking the stack down above the roof, or a house in a conservation area, where the rules can differ.
If you are not sure which of those three permissions applies to your house, planning permission, building regulations and listed building consent sets out the difference, and building notice or full plans explains the two ways to apply. For structural work, full plans gets the design checked before the steel is bought.
Supporting what is left
Gallows brackets or a steel beam
The chimney that stays is carried either on steel brackets bolted to the wall under it or on a steel beam bearing on walls either side. Which one depends on the wall, the stack, next door, and what your building control team will accept.
Gallows brackets
A gallows bracket is a triangle of steel angle anchored into the wall, with a plate on top for the chimney to sit on. It needs no bearing on another wall, but it puts the whole stack into a handful of bolts in old brickwork, which is why some councils have tightened up.
Redbridge building control now says it will no longer accept gallows brackets unless its guidance is followed, that brackets must be justified with a structural design or calculation, and that pull-out testing has to be provided before the work is finished. Its conditions include a party wall of at least 215mm of sound brickwork, a house of no more than two storeys, a chimney breast no wider than 1200mm and projecting no more than 340mm, and next door’s breast still in place. If next door’s has already gone, it says the chimney above the roof should come down or a steel beam be used.
Harrow’s guidance note goes the same way: gallows brackets are not permitted on a party wall if the chimney on the other side has already been removed and is sitting on brackets, and at least two thirds of the height of the stack that is kept should stay within the loft. Those are two London councils, and yours may be looser or tighter, so ring building control before you collect quotes rather than compare prices for a method they will not sign off.
A steel beam
A beam spans under the chimney and bears on walls that can take the load, or on posts down to foundations. Richmond’s guidance says a beam can be used instead of brackets provided it is supported on suitable load-bearing walls, and that corbelling the brickwork out below the stack is not enough. A beam needs an engineer’s calculation for its size and its bearings. Redbridge also asks for at least 30 minutes’ fire protection to brackets or beams unless they are wholly in the roof space, so expect the steel to be boxed in and plastered.
| Option | When it tends to suit | What building control is likely to want | The catch |
|---|---|---|---|
| Gallows brackets | A modest stack on a sound, solid brick wall, with next door’s breast still in place. | An application, and on some councils a calculation and pull-out tests on the anchors. | Some councils restrict or refuse them. Ask first. |
| Steel beam, or beam and posts | Wider or heavier stacks, thinner walls, or where brackets are not accepted. | An application with a structural engineer’s calculations and fire protection to the steel. | More disruption, because the beam needs bearings, often in the loft or the rooms either side. |
| Take the whole chimney down | Every breast and the stack are coming out anyway, or the stack is in poor condition. | Ask building control. The roof and possibly a party wall are affected, and a stack that acts as a buttress needs the wall checked. | The roof has to be made good, and the stack may need planning permission to remove. |
| Leave it, cap it and vent it | The real problem is damp, draughts or an unused fireplace. | Nothing, for capping and venting a flue. | You keep the breast, but nothing structural changes. |
The engineer
What the structural engineer’s calculation is for
The engineer’s calculation is the heart of what building control checks. A structural engineer looks at the brickwork that stays, what it will sit on and the wall it is fixed to, then specifies the steel, the fixings and the bearings. You send that with the application, and the inspector checks the work against it on site.
It also catches the jobs that should not go ahead as planned. Redbridge warns that some chimneys act as a buttress for a long wall, and that where that is the case you should consult a structural engineer. Richmond puts a number on it: on a two storey house a wall must not exceed 9m without a buttress, 12m on a single storey building. Some older terraces have cross-over flues, where a flue from next door’s fireplace runs up through the breast on your side of the wall. Redbridge says that in that case the breast cannot be removed. Narrow stacks with the pots in a single line are the clue.
On an upstairs breast, Redbridge also says the concrete hearth should come out and new joists go in, properly carried by the trimmers either side. Boarding over the hole leaves a soft spot in the floor.
Next door
If the breast is on a party wall
Most chimney breasts in terraced and semi-detached houses are on the wall you share with next door, and that makes the work notifiable. Section 2 of the Party Wall etc. Act 1996 gives a building owner the right to cut away from a party wall any projecting chimney breast, jamb or flue, and section 3 says a party structure notice must be served at least two months before the work begins.
Building control does not administer the Act, so they will not check the notice for you. Plan the two months into the start date, and read the Party Wall Act for a chimney, a garden wall and an extension for what happens if your neighbour says nothing or dissents. You can serve the notice yourself, and if your neighbour consents in writing no surveyors need to be appointed.
Redbridge also warns that damaged brickwork between flues can let carbon monoxide through from next door’s flue, and asks for a smoke test where possible, so find out whether next door uses that chimney before the job starts.
The stack
Leaving the stack in place, or taking the whole chimney down
Taking out one breast keeps everything above it, which is why it needs support. Taking out every breast and the stack removes the problem rather than holding it up, but it means opening the roof, filling the hole and tiling or slating it in to match.
The Planning Portal says the rules may differ for removing a stack and in a conservation area, so ask the planning department before you commit. A row of matching stacks along a terrace is often exactly what a conservation area or an Article 4 direction is there to protect.
Where a stack on an outside wall is only partly removed, for instance on the end house of a terrace, Richmond recommends cutting it down to no more than 1m above where it comes out of the roof. And whether building control needs an application for removing the whole chimney is a question to put to them directly: the roof and any party wall are still affected, so do not assume it is exempt.
If the stack is leaning, cracked or losing its pointing, price the chimney repairs alongside the removal, because supporting a stack that is falling apart from the top is money in the wrong place.
Before anything is demolished
Gas, asbestos and the flue that stays
Gas first. If a gas fire, boiler or any other gas appliance uses the flue, it should be disconnected and made safe by a Gas Safe registered engineer before any demolition starts.
Under regulation 3 of the Gas Safety (Installation and Use) Regulations 1998, no employer or self-employed person may carry out work on a gas fitting unless they belong to the class of persons approved by the HSE, and the HSE explains that this means being on the Gas Safe Register. Ask to see the engineer’s ID card.
Asbestos is the other thing to check in a house built before 2000. The HSE says buildings constructed after 2000 are unlikely to contain it. Around a fireplace one place to look is an old flue pipe from a gas fire or back boiler, since the HSE lists cement flues in domestic boiler systems among asbestos cement products. If you suspect it, get it sampled before anyone breaks it up.
Whatever stays of the flue has to be looked after. A flue capped solid at the top and blocked at the bottom becomes a cold, still shaft lined with damp soot, and it condenses. Redbridge asks for the pot to be capped with a ventilated cowl and an air brick fitted at low level, so air keeps moving through what is left. If the breast upstairs is damp, a damp patch on a chimney breast walks through the causes. Plenty of breasts are taken out to cure damp that a vented cap and an air brick would have cured on their own.
Selling or remortgaging
The completion certificate, and what happens without one
The certificate is the proof a buyer’s solicitor will ask for. The government’s guidance warns that without approval you will not have the certificates of compliance you may need when you sell your home. With a full plans application, you will usually get a completion certificate within 8 weeks of the work being finished, as long as it complies. Keep it with the engineer’s calculations and the party wall paperwork.
If a previous owner removed a breast and there is no paperwork, look in the loft or the room above: the stack should be sitting on steel, not hanging off the wall or propped on timber. Cracks in the breast upstairs, or doors starting to bind, can be signs that the support is not doing its job.
A local authority building control team can issue a regularisation certificate for work done without approval after 11 November 1985. The gov.uk guidance says you may have to make alterations first, and expect the support to be opened up for inspection. Do it before a sale, not during one.
What to do next
The order to do it in
- Decide whether you need the breast out at all. If the problem is damp or draughts, cap and vent the flue first and see.
- Ring your building control team and ask whether they accept gallows brackets for your house, or want a beam.
- Get a structural engineer to design the support and submit a full plans application with the calculation.
- If the breast is on a party wall, serve the party structure notice at least two months before the start date.
- Have a Gas Safe registered engineer disconnect any gas appliance, and get anything that might be asbestos sampled.
- Get quotes that name the support method, the fire protection, the joists, the making good, and the capping and venting of the flue that stays. Anything missing will be an extra later.
- Keep the completion certificate.
Chimney breast removal and the support work that goes with it is part of our bricklaying and repointing work, and the boxing in and making good afterwards is plastering. Where the stack is coming down, the roof is made good as part of our roofing work.
Thomas Hannen comes out to look at the chimney himself, from the room and the loft, and you get a free written itemised quote that lists each of the steps above that applies to your house, including what the engineer and building control still have to decide.
Questions
Common questions
Do I need building regulations approval to remove a chimney breast?
Yes. The Planning Portal says building regulations approval will always apply, because a chimney breast is part of the structure. The chimney left above has to be supported, and a structural engineer's calculation usually goes with the application.
Do I need planning permission to remove a chimney breast?
Not to remove an internal chimney breast, because the outside of the house does not change. A listed building needs listed building consent, and taking the stack down above the roof or working in a conservation area can need permission, so ask the planning department.
Are gallows brackets still allowed?
Often, but on conditions that vary between councils. Some now ask for an engineer's calculation and pull-out tests on the anchors, and some do not allow them on a party wall where next door's breast is already on brackets. Ask your building control team before choosing.
Do I need a party wall agreement to remove a chimney breast?
If the breast is on a wall you share with next door, you must serve a party structure notice at least two months before work starts. If your neighbour consents in writing, no surveyors are needed. If they dissent or do not reply, surveyors settle the terms.
What if a previous owner removed the chimney breast without approval?
Check that the stack above is sitting on steel and not hanging off the wall. Then ask the council's building control team about a regularisation certificate, which covers work done after 11 November 1985 and may need the support opened up for inspection.
Read next
Related advice
The guides below pick up where this one leaves off, and the bricklaying and repointing page covers the work itself and the places we cover, if you would rather have the job looked at.
- The Party Wall Act for a chimney, a garden wall and an extension
- A damp patch on a chimney breast: leak, condensation or salts?
- Building notice, full plans or a competent person: which applies to your job
- Planning permission, building regulations, listed building consent: which one you actually need
Bricklaying and repointing, and where we cover All advice articles
Who wrote this
Thomas Hannen
Thomas owns Bournemouth Roofing & Building and prices every job himself instead of sending somebody else. The company is Bournemouth Roofing & Building Ltd, number 15471719, registered in England and Wales. If you want to talk something through before you commit to anything, the site visit and the written itemised quote are both free.
Free quote
Thinking about taking a chimney breast out?
Thomas comes out, looks at the breast, the loft and the stack, and puts what he found in a written, itemised quote, including what the engineer and building control still need to settle and whether removal is the right answer at all.