Chimney Breast Removal: What's Involved and What It Costs

A Victorian or Edwardian chimney is typically a continuous masonry stack that runs from the foundations through all floors of the house and exits through the roof. In a typical two-storey London terrace:

• •**Ground floor chimney breast**: the lowest visible section in the ground floor reception room, containing one or two fireplace openings
• •**First floor chimney breast**: the section directly above on the first floor, often in a bedroom
• •**Stack above roof level**: the section that exits through the roof and terminates in chimney pots

The critical structural point: if only the ground floor chimney breast is removed and the first floor breast and stack above remain, the weight of the first floor breast and stack must be transferred to a new support. The remaining breast above cannot just 'hang in the air' — it requires an RSJ (steel beam) inserted at first floor level to carry the load of the masonry above.

**Three common removal scenarios**:

• *Ground floor removal only*:
• •Most common scenario — removes the chimney breast from the ground floor room while retaining the first floor and above
• •Requires an RSJ installed at first floor level to carry the load of the first floor breast and stack
• •The RSJ sits in the party wall (or gable wall) at each end — requiring padstones and potentially party wall notice
• •The first floor floorboards and structure must be temporarily propped during steel installation

• *Ground floor and first floor removal*:
• •Both chimney breasts removed, leaving only the stack above the first floor ceiling
• •Requires an RSJ at second floor level (or at the base of the roof structure) to carry the stack above
• •More complex, more expensive, more intrusive — but frees maximum space on both floors

• *Full removal (including stack)*:
• •All chimney breast and stack removed from the property — including the section above roof level
• •The roof where the stack exits must be carefully made good — the stack exit is usually via a purpose-formed penetration in the roof, which must be properly flashed and waterproofed after removal
• •No structural steel required if no chimney breast remains (no weight to transfer), but the opening left in the roof requires specific attention
• •Most invasive and most expensive — typically only justified on major refurbishments

**Structural engineer requirement**: Chimney breast removal requires a structural engineer to design the new load path — specifically the RSJ required to carry the remaining structure above. Building Control will not approve the work without an engineer's design and calculation.

• The engineer will specify:
• •The RSJ section (depth, weight per metre) adequate for the load
• •Padstone size and specification at each end of the beam
• •Temporary propping arrangement during installation
• •Any implications for the party wall at the beam bearings

• **Building Regulations (Part A — Structure)**:
• Chimney breast removal is notifiable under Building Regulations — a structural alteration affecting a load-bearing element. Approval is required:
• •Either through Full Plans Approval (FPA) before work starts — which gives a formal approval notice from Building Control
• •Or through a Building Notice — which allows work to start sooner but requires regular on-site inspections by the Building Control officer

• Building Control inspections for chimney breast removal typically include:
• •Inspection before the propping is put in place (to confirm the temporary works arrangement)
• •Inspection before the RSJ is positioned and masonry made good (to confirm steel size and padstones match the specification)
• •Final inspection after making good

**Party Wall implications**: In a mid-terrace Victorian property, the chimney breast is typically on the party wall — shared with the adjacent property. The RSJ required to carry the remaining stack above will bear on the party wall at each end.

• This constitutes 'work on the party wall' under the Party Wall etc. Act 1996 — specifically Section 2 (works to a party wall). A Party Wall Notice must be served on the adjoining owner before the works start. The neighbour has 14 days to:
• •Consent in writing (the work can proceed)
• •Dissent (triggering the party wall award process — appointment of surveyors, production of a schedule of condition and award)
• •Not respond (deemed dissent after 14 days — surveyor appointment follows)

For chimney breast removal in mid-terrace properties, assume a Party Wall Notice will be required — budget for it (surveyor fees £1,000–£2,500 per surveyor) and allow the 14-day notice period in your programme.

**Typical costs (London 2025)**:

• *Ground floor chimney breast removal only (RSJ at first floor level)*:
• •Structural engineer (calculation + specification): £500–£1,200
• •Building Control (Building Notice or Full Plans): £400–£800
• •Contractor works (demolition of breast, temporary propping, RSJ installation, padstones, making good): £2,500–£5,500
• •Party wall surveyors (if required): £1,000–£2,500
• •Decoration making good: £500–£1,500
• **Total: £5,000–£11,500 approximately (all in)**

• *Ground floor and first floor chimney breast removal*:
• •More extensive — typically £3,000–£7,000 for the contractor works element; total £7,000–£15,000 all-in

• *Full chimney breast and stack removal*:
• •Roof making good significant — typically £8,000–£20,000 all-in depending on property size and specification

• **Programme**:
• •A straightforward ground floor breast removal with an efficient contractor: 3–6 working days for the structural works, plus decoration making good
• •Allows for Party Wall Notice period (minimum 1 month before work starts after the notice is served and agreed) in the overall programme

**Does it add value?** In a typical London Victorian terrace, removing the chimney breast from the ground floor reception room creates a materially more spacious and usable open-plan living area. This generally adds value — a well-executed removal on a narrow-fronted Victorian terrace (14–16ft wide typical) can transform the feel of the ground floor and increase sale value.

• However:
• •Retain the fireplace opening if you can — original fireplaces with period surrounds are valued by buyers and can be retained even after chimney breast removal by creating a false breast or recessing behind the RSJ line
• •The quality of making good matters — a poorly patched ceiling or wall around the removed breast is an obvious tell and reduces the perceived quality
• •An unsupported stack (where a breast has been removed without proper RSJ support) is a serious defect that will be caught by a building survey and can prevent a mortgage and sale — always use a structural engineer