Chimney Breast Removal Forest Hill

Forest Hill's Victorian houses, and the flats carved out of them, have generous rooms, but a breast in a bay-fronted front room still eats the one wall you would put a piano or a bookcase against. Take it out and that wall is yours again. We appoint the structural engineer, install the beam carrying the stack above, and do the plastering ourselves.

In Forest Hill, 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 Forest Hill.

How the job runs

1. Free site survey at your Forest Hill 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 Lewisham 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.

Supporting the stack in Forest Hill terraces

In Forest Hill's terraces the chimney breasts sit against the party wall, with flues shared through it with the house next door. When we remove a breast at ground or first floor, the masonry stack above still needs carrying, and it must never be left hanging. We assess exactly what is above before any brickwork is cut, because a stack left unsupported is a serious hazard.

The usual solution is a steel beam on padstones, designed by the engineer to catch the retained stack; gallows brackets bolted into the party wall are used only where the engineer and building control accept them for that wall. On the taller SE23 houses where the stack runs full height and is redundant, we more often remove the whole stack and make the roof good with matching tiles and sound weatherproofing.

Housing in Forest Hill

Forest Hill has around 11,040 homes on the Council Tax list: 30% post-war, 13% interwar and 54% predate 1919, with 58% flats and 42% houses. Since most homes here are flats, a chimney breast in a flat in Forest Hill often supports the breasts in the flats above, so removal needs the freeholder's licence and designed support.

Taking a Forest Hill chimney stack off the roof needs a planning check

Removing a chimney breast inside is a building control matter, but taking the stack down above the roof changes the outside of the house. The Forest Hill conservation area was originally designated in 1976 and extended in 1994 and in 2010, so a house that stood outside it when an earlier owner altered the roof may be inside it now. Where an Article 4 direction applies, Lewisham lists alterations to the roof of a house among the changes needing planning permission. We check the current boundary and any direction for your address before the scaffold is booked.

Whether you own a house or a flat changes the answer. Lewisham's Article 4 directions in conservation areas only apply to houses in use as a single dwelling house. A flat is caught by a wider rule: Lewisham says flats or subdivided houses in conservation areas do not have permitted development rights for exterior changes. In a Forest Hill villa split into flats inside a conservation area, a stack coming down changes the exterior of the whole building, so the application, the freeholder's consent and any flues other flats still use are dealt with together. Where the stack stays and only a breast comes out, the question returns to building control.

Party wall and building control in SE23

Because Forest Hill's terraces are built tight against each other, the chimney stack almost always sits within the shared party wall. Removing the breast, and bearing a beam or fixing brackets into that wall, affects your neighbour's structure, so the work is notifiable under the Party Wall Act and you serve notice as building owner before starting. It is a routine step, and we give you the drawings the notice needs.

The structural support is notifiable under the Building Regulations, so Lewisham Council's building control inspects the brackets or beam and signs the work off; this internal work needs building control, not planning permission, though a listed home also needs listed building consent. We cap any redundant flue with ventilation to keep it dry, make good the floor and ceiling line, and replaster so there is no trace the breast was ever there.

Scaffolding and taking a stack down safely

If the stack is coming off the roof, the work happens outside as well as in, and that means scaffolding. On Forest Hill's steep streets a scaffold often has to be built off sloping ground or over a front lightwell, which takes longer to design and sometimes needs a licence from Lewisham Council where it stands on the pavement. A mobile tower is rarely enough for anything beyond the smallest stack.

The brickwork is then taken down by hand, course by course, and lowered rather than pushed in. Dropping a stack down the inside of the flue sounds quicker, but it fills the house with soot and can break through a ceiling below. Once the masonry is below roof level, the opening is framed, membraned and tiled from the scaffold while it is still standing, which is why the roofing follows straight on rather than waiting for a second visit.

• Programme planned around party wall notice periods for a shared stack
• Ventilated caps and airbricks to disused flues
• Chimney breast removal on one floor or on every floor

VOA Council Tax stock of properties, March 2025, for Forest Hill West, Forest Hill East and Honor Oak. Counts rounded by the VOA.

If this is your first project in Forest Hill, these are worth a look: home renovation in Forest Hill, chimney breast removal across Lewisham, builders across London, party walls and chimney breasts, our London chimney breast removal page and Party Wall Act Explained.

Trusted Chimney Breast Removal in Forest Hill

Forest Hill homeowners choose GS Renovation because we treat a chimney breast as the structural job it is. You get an engineer-checked support solution, a steel beam, or gallows brackets where the engineer and building control accept them, properly fixed, the drawings for the party wall notice you serve on your neighbour, and Lewisham building control handled end to end, plus tidy working and a fully replastered finish, 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.