Chimney Breast Removal Highgate

A capped flue still has to breathe. We fit a cap at the head and an air brick low down, so the disused shaft in your Highgate house stays dry rather than pushing damp through fresh plaster. The rest is methodical: engineer's beam, careful propping, and the wall brought back flush and finished.

In Highgate, removing a breast on one floor typically costs £2,200 to £3,250 on a steel beam, and £3,000 to £5,000 across two floors (indicative London ranges, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Highgate.

How the job runs

1. Free site survey at your Highgate address: which floors the breast runs through, a shared stack, any live flue.
2. The engineer we appoint designs the support, and the work is registered with Camden Council building control or an approved inspector. On a shared wall you serve the party wall notice as building owner; we supply the drawings.
3. The floor above is propped and the breast comes down in courses from the top; what remains sits on the support the engineer specified.
4. Building control inspects the support before it is covered. We make good, and the completion certificate follows.

Removing a chimney breast in Highgate

Most of Highgate's period homes still carry their original chimney breasts, often several per house across the reception rooms and bedrooms of these tall houses. Because the breast helps carry the masonry stack above, it can never simply be knocked out; we start every job with a structural engineer confirming what is being supported and how the retained stack will be held once the breast below is gone.

Where a breast is removed on a lower floor, the stack above is carried on a steel beam bearing on padstones, sized by the engineer we appoint. Gallows brackets are used only where the engineer and building control both accept them for that stack. In the taller N6 houses, where the stack runs the full height, it is often more sensible to remove the whole stack and make the roof good rather than leave masonry hanging.

Housing in Highgate

Highgate's housing, as the Council Tax list records it, is about 10,090 homes: 31% houses, 69% flats, with 47% pre-1919, 24% interwar and 28% built since 1945. Where most homes are flats, a chimney breast in a flat in Highgate often supports the breasts in the flats above, so removal needs the freeholder's licence and designed support.

Which Camden route a Highgate chimney breast removal takes

The route depends on whether you own a house or a flat. 69% of Highgate homes are flats and 31% are houses. The owner of a whole house can use a Camden building notice, with no detailed plans, and start within 2 days of applying, but gets no formal approval. For a breast whose stack stays in place above, that means the support detail is first judged on site, with the masonry already open. A full plans application gets the steel or bracket design approved before the first brick comes out, which is the safer order where a stack serves several floors.

A leaseholder does not have that choice. In Camden a leaseholder must have the freeholder's consent and must make a full plans application rather than a building notice. In a converted Highgate house the stack is usually part of the common structure that also carries the flats above, so the freeholder's consent is needed even though the breast is inside your flat. Where the stack above the roof is to come down, a planning application in a Camden conservation area must include a heritage statement describing the significance of what is affected.

Party wall and building control in N6

Where a Highgate house adjoins its neighbour, the chimney stack almost always sits within the shared party wall. Removing the breast, or bearing new steel into that wall, affects the neighbour's structure, so it is notifiable under the Party Wall Act and you serve notice on the adjoining owner before any work begins. We give you the engineer's drawings for it.

The support to the retained stack is structural work under the Building Regulations, so building control at Camden or Haringey, depending on the address, inspects it and issues the completion certificate. We handle the whole sequence: appointing the engineer, safe removal and propping, capping any redundant flue with ventilation to stop damp, and replastering so the room is left flat and finished.

Working through a house with several stacks

A Highgate house of any size often has four or six breasts spread across three or four floors, and very few owners want to lose all of them. The useful question is which ones actually cost you space. A breast in a small back bedroom or a top-floor room is usually worth removing, while one in a large reception with an original surround is worth keeping and restoring, because it still earns its place in the room.

Where several are coming out, the order matters. Breasts stacked directly above one another are more efficient to remove together than one at a time, because the support only has to be designed once, at the highest point that remains. We normally work from the top of the run downwards, floor by floor, so the house is never left in a half-finished structural state, and we phase the rooms so you can stay living in N6 throughout.

• Bedroom breast removal to reclaim usable floor space
• Structural engineer's calculations arranged and followed
• Loft inspection of the retained stack before work starts

VOA Council Tax stock of properties, March 2025, for Highgate West, Highgate East and Highgate Wood. Counts rounded by the VOA.

Related reading for Highgate homeowners planning chimney breast removal: home renovation in Highgate, chimney breast removal across Camden, builders across London, the Party Wall Act for a breast in a shared wall, chimney breast removal anywhere in London and Party Wall Act Explained.

Why Highgate Homeowners Choose GS Renovation

Highgate homeowners choose GS Renovation because we never leave a stack unsupported. You get a steel beam designed by the engineer we appoint, with gallows brackets only where building control accepts them, the drawings for the party wall notice you serve, building control sign-off, flues capped and ventilated against damp, and tidy working in an occupied home, all backed by our founder's 30+ years on the tools.

Checked by Abdelaaziz Saaid, founder and director of GS Renovation Ltd (Companies House no. 14611254). Structural design is by the consulting engineer appointed to your project.