Notes
Removing a chimney breast, and what holds up the chimney that stays
Take the breast out downstairs and the chimney above it is still there, and still heavy. Something else has to carry it.
Drawing made for this site. True proportion, not a design.
Key to the drawings
- Existing masonry A flat tone: everything already there, cut or seen.
- Concrete Aggregate triangles and fine dots, scattered at random: foundations, slabs, padstones, lean-mix cavity fill, encasement.
- Undisturbed ground Basket weave, as a band that follows the ground line and fades out.
- Hardcore Large open zigzag, the depth of its own layer.
- Timber, cut A box with a cross. Seen along its length, an outline only.
- Steel, cut Solid, at the section's true proportion.
- DPC Heavy dashed line, as Approved Document C draws it.
- Load path Where the load goes, from the roof to the ground; dashed where it runs beyond the cut.
- Load marks Arrows at the symbol weight: loads down onto a member, bearing up under a foundation.
- Hidden, beyond or removed Out of the cut, beyond it, or taken out.
- Cloud Confirm on site. Never a revision mark.
- Break line The drawing stops; the building does not.
What does a chimney breast hold up?
A chimney breast is the brick casing round the flues, built out from the wall into the room. Everything above stands on it: the breast upstairs, the brickwork gathering the flues in the loft, and the stack on the roof. Take the bottom out and the rest hangs on whatever it is bonded to, which was never built to carry it. Some breasts also stiffen the wall behind them, so we check that too.
How is the chimney above held up?
Usually with steel: a beam, or a pair side by side, under the breast that stays, each end on a padstone in a wall with its own foundation. In the drawing it spans the room inside the floor, so the ceiling stays flat. Each bearing is checked all the way down, because a wall that carried little may now be carrying a chimney. Nothing passes through the party wall: a bearing that has to go into it stops in your half. The steel is then protected from fire, usually boxed in with fire-rated board.
Are gallows brackets still allowed?
Gallows brackets are steel angle brackets bolted to the party wall under the breast that stays. They are quick and cheap to fit, and were once the usual answer. But they hang the chimney on bolts in old brickwork, and everything depends on the mortar.
Drawings made for this site. True proportion, not a design.
Building Control now treats them warily. Harrow's guidance still shows a bracket, but not on a party wall where next door's chimney is already on brackets. Redbridge wants a structural design and pull-out tests on the fixings. In January 2026 the expert panel of CROSS, the structural safety reporting scheme, found brackets hard to justify in older brickwork laid in lime mortar, and preferred properly designed steel. So we start from a beam.
Sources: Harrow Council Building Control, “Removal of Chimney Breasts in Dwellinghouses”, October 2024; Redbridge Council, “Chimney breasts removal”; CROSS-UK, report 1501, 20 January 2026.
Do I need a party wall notice to remove a chimney breast?
Yes, if the breast is on the party wall, as it usually is in a terrace or a semi. The Party Wall etc. Act 1996 gives you the right to cut away a chimney breast projecting from it on your side, as long as you make good any damage next door. Notice goes at least two months before the work starts, and if next door does not agree, surveyors settle it with a party wall award. We do party wall surveys.
What about next door's flue?
The party wall is also the fire wall between the two houses, so it is made good where the breast came off. If next door still uses a flue in the same chimney, the brickwork between the flues matters most: damaged, it can let fumes, carbon monoxide included, into either house. Redbridge asks for it to be rebuilt and, where possible, next door's flue smoke tested. Where the flues cross over between the houses inside the chimney, it says the breast cannot come out at all.
Sources: The Building Regulations 2010, Schedule 1, requirement B3(2); Redbridge Council, “Chimney breasts removal”, sections 1.5 and 6.1.
Source: Party Wall etc. Act 1996, sections 2(2)(g), 2(5) and 3(2)(a). Drawing made for this site, not a design.
Do I need Building Regulations approval to remove a chimney breast?
Yes. Taking out a breast that carries anything is a material alteration, because at some stage it would leave the house short of Part A, the structure requirement, and a material alteration is building work. With the council you apply with full plans, checked before work starts, or give a building notice and are inspected as you go; a private building control firm works through an initial notice instead. Either way they need the same from us: calculations for the beam and its bearings, and a drawing of where it goes.
Selling, where a breast went years ago without approval? The council can issue a regularisation certificate, and may want the support opened up to see it.
Sources: The Building Regulations 2010 (England), regulations 3, 12 and 18; Building Act 1984, section 47.
Could you take the whole chimney down instead?
Yes, and then nothing is left to hold up: the stack comes down below the roof, the roof is made good, and the breasts come out floor by floor. A stack shared on the party wall needs next door's side left sound and weathertight, and removing a chimney from a party wall is work you must tell them about. On a listed house, works that affect its character need consent first.
Sources: GOV.UK, “Party walls and building work”; Planning (Listed Buildings and Conservation Areas) Act 1990, section 7.
What we need from you
- Photographs of the breast in each room, and of the stack from outside.
- A photograph in the loft, where the chimney passes through.
- Floor plans, or a sketch showing the rooms and the walls.
- Whether a fire, stove or boiler still uses the chimney, yours or next door's.
- Whether next door has already taken their breast out.