How to Price Chimney Breast Removal: Labour, Materials and Margin Guide

Quick Answer: Removing a chimney breast in a typical UK home costs roughly £1,500–£3,500 for a single-floor (ground or first floor) removal, and £3,000–£6,500+ where you take out the full stack including the chimney above roof level. The two costs that make or break the job are structural support (how you carry the breast left standing above the removal — gallows brackets or a steel beam) and Building Control approval under Part A, which almost always requires a structural engineer's calculations. Price these in properly or the job loses money fast.

Summary

Chimney breast removal is deceptively simple to describe and structurally serious to deliver. The breast is load-bearing for everything above it — the masonry chimney, the stack on the roof, sometimes a party wall flue shared with next door. Whenever you remove a section of breast lower down and leave masonry standing above, that retained mass has to be supported. Get this wrong and you have an unsupported tonne of brickwork sitting over a living space. This is why the job is notifiable to Building Control under Part A (structure) and why a structural engineer's calculations are effectively mandatory, not optional.

For pricing, the single biggest variable is the support method. Two routes exist: gallows brackets (steel brackets bolted into the retained party/flank wall, cantilevering a small concrete or steel lintel under the breast above) which are cheap but only acceptable for limited loads in sound brickwork with engineer sign-off; or a steel beam / RSJ spanning to padstones, which costs more but carries far heavier loads and is what Building Control will demand for first-floor and full-stack removals. The wrong assumption here can swing the quote by £1,000+.

Beyond support, the quote must cover making good (floor, ceiling, walls, plaster, skirting), dealing with the now-redundant flue and any ventilation requirement, waste removal, and — on semi-detached and terraced homes where the chimney sits on a shared wall — a Party Wall etc. Act 1996 agreement. Many tradespeople under-quote by ignoring making-good and the party wall process, then absorb the cost. This guide breaks every element down so the quote stands up.

Key Facts

Quick Reference Table

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Element Typical Cost Notes
Structural engineer calcs £350–£750 Mandatory in practice; more for full report
Building Control fee £300–£600 Building Notice or Full Plans; varies by authority
Gallows brackets (pair) £80–£250 Limited loads only; needs engineer + BCO sign-off
Steel beam (RSJ) + padstones £600–£1,400 installed Default for first-floor / full-stack support
Single-floor breast removal (all-in) £1,500–£3,000 Ground floor, support + making good + waste
First-floor breast removal (all-in) £1,800–£3,500 More retained masonry above
Full breast + stack removal £3,000–£6,500+ Scaffold + roof works dominate
Party Wall agreement £0–£2,000+ Free if consented; surveyor fees if dissent
Skip (6–8 yd) £220–£380 Heavy masonry — watch weight limits
Scaffolding (2-storey) £600–£1,500 Required for stack removal
Plastering recess wall £350–£700 Per affected wall
Floor/ceiling making-good £200–£600 Hearth removal, joist infill, patch
Roof making-good (stack) £400–£1,200 Re-tile, leadwork, felt the gap
Builder/bricklayer day rate £200–£320 Regional; London higher
Plasterer day rate £180–£280

Detailed Guidance

Partial vs Full Removal

The scope defines almost everything else in the quote.

Always confirm with the client which fireplaces (if any) elsewhere in the property remain in use, because a shared flue or a retained breast above changes the support design.

Supporting the Breast Above (Gallows Brackets vs Steel)

When you remove a lower section and leave masonry above, you transfer that load into the retained wall (usually the party wall in a terrace/semi, or the flank/gable wall). Two methods:

Gallows brackets. A pair of welded steel brackets bolted to the retained wall, cantilevering out to support a concrete or steel lintel on which the breast above sits. They are cheap and quick, but they are only acceptable for limited loads — typically supporting the first-floor breast and stack of a modest two-storey house — and only where the retained brickwork is sound, well-bonded, and thick enough to take the bolt fixings. Crucially, gallows brackets are not a guaranteed approval: the structural engineer must calculate that the load is within limits and that the host wall can carry it, and the Building Control surveyor must accept the design. Some authorities are reluctant to accept gallows brackets for heavier loads and will insist on a beam. Never quote gallows brackets as a foregone conclusion — quote it as "subject to engineer's calculations and Building Control acceptance," and price the steel-beam fallback so you are not exposed if they reject brackets.

Steel beam (RSJ) and padstones. A steel beam spans the opening and bears onto padstones (concrete or high-strength engineering bricks) built into the supporting walls at each end. This carries far heavier loads than brackets and is the default for first-floor breast removal, full-stack-retained jobs, or any case where the engineer's numbers exceed bracket capacity. It costs more — steel, padstones, needling/propping to insert it, and often a wider builder's opening — but it is robust and rarely refused by Building Control.

The decision is the engineer's, not yours. The quoting risk is assuming brackets and being told to use a beam. Build a clear provisional sum or a clause that the support method is confirmed by the engineer's calculations.

Building Control, Structural Engineer and Party Wall

Building Control (Part A — Structure). Removing a load-bearing chimney breast is notifiable building work. You submit either a Building Notice (simpler, no detailed plans up front, suited to straightforward jobs) or a Full Plans application (plans and calcs submitted and approved before work starts). The surveyor inspects the support installation before it is covered up and issues a completion certificate. Skipping this leaves the homeowner with unauthorised structural work that surfaces on sale — a real liability you should warn them about.

Structural engineer. In practice every breast removal needs a chartered/qualified structural engineer to produce calculations for the chosen support, specify the steel section or bracket detail, and size the padstones. Building Control will want to see these. Budget £350–£750 for the calc package; more if a full report or repeat visit is needed. The engineer's fee is usually a pass-through cost on the quote, clearly itemised.

Party Wall etc. Act 1996. On a semi-detached or terraced property the chimney breast almost always sits on the party wall shared with the neighbour. Cutting into, removing, or fixing brackets/beams into that wall is notifiable work under the Act. You must serve a Party Structure Notice on the adjoining owner (typically two months before work). If they consent in writing, cost is nil. If they dissent or don't respond, the dispute resolution process kicks in and surveyors are appointed — fees of £700–£2,000+ per surveyor, usually paid by the building owner (your client). This is the most commonly forgotten line in a chimney quote. Flag it explicitly for any non-detached property.

Making Good

The destructive part is fast; making good is where time and money go, and where under-quoting happens.

A realistic making-good allowance is often 30–40% of the total job. Builders who quote only the demolition and steel lose this margin.

The Redundant Flue and Ventilation

When a chimney breast is removed but a flue is retained anywhere in the system (e.g. you take out the ground floor but a flue still serves an upstairs fireplace, or the stack stays), the flue must be ventilated to prevent damp and condensation building up in the disused void. Standard practice is to fit air bricks/vents top and bottom of the retained flue. Where the stack is fully removed, the roof opening is capped and weathered. Any retained working appliance flue must still comply with Approved Document J (combustion appliances and fuel storage systems) for ventilation and flue requirements. Itemise a vent allowance — it's cheap (£20–£60 in materials) but skipping it causes callbacks for damp staining.

Labour and Materials

Typical labour mix for a ground-floor breast removal:

Materials: steel beam or gallows brackets, padstones, props/Acrow and strongboys for temporary support, plasterboard, bonding/skim, sand and cement, lintels, air bricks, fixings. Plus skip(s) — chimney masonry is heavy, so budget by weight; a single breast can fill a 6-yard skip with brick and a builder's worth of waste.

Margin and Quoting

Common Mistakes

Frequently Asked Questions

How much does it cost to remove a chimney breast?

A single-floor (ground or first floor) removal in a typical UK home runs £1,500–£3,500 all-in, including structural support, making good and waste. Removing the full chimney including the stack above the roof is £3,000–£6,500+ because of scaffolding and roof reinstatement. Structural engineer (£350–£750) and Building Control (£300–£600) fees sit on top and are usually itemised separately.

Do I need Building Regulations approval?

Yes. A chimney breast is load-bearing, so removing it is notifiable building work under Approved Document A (structure). You'll submit a Building Notice or Full Plans application and the surveyor will inspect the support before it's hidden, then issue a completion certificate. Doing the work without this leaves unauthorised structural alterations that cause problems when the property is sold.

Gallows brackets or a steel beam?

It depends entirely on the load and the condition of the supporting wall — and it's the structural engineer's decision, not yours. Gallows brackets are cheaper but only acceptable for limited loads in sound, well-bonded brickwork, and the Building Control surveyor must accept the design. For first-floor removals, full-stack-retained jobs, or heavier loads, a steel beam (RSJ) on padstones is the norm. Never quote brackets as a certainty — price the beam fallback.

Do I need a party wall agreement?

If the property is semi-detached or terraced and the chimney sits on the wall shared with the neighbour (it almost always does), then yes — work to that wall is notifiable under the Party Wall etc. Act 1996. You serve notice on the neighbour roughly two months ahead. If they consent in writing it costs nothing; if they dissent, surveyors are appointed and fees of £700–£2,000+ apply, usually paid by your client.

How long does it take?

A ground-floor breast removal is typically 2–4 days on site plus drying time before final decoration. A full chimney and stack removal is 5–10 days including scaffold erection and strike, roof making-good and internal finishing.

Regulations & Standards