House Extensions Chislehurst

GS Renovation builds extensions across Chislehurst, adding space to its mostly post-war semis and detached houses, its terraces and the substantial period homes near the common. We manage the whole project, from foundations and steelwork to the final fit-out.

In Chislehurst, a single-storey rear extension typically starts from £40,000, or £2,000 to £2,800 per m² (indicative London ranges, Architecture for London, Resi, MyBuilder and Checkatrade, 2026). GS Renovation Ltd, a building contractor based in Potters Bar, does the work in Chislehurst: the structural engineer we appoint designs the structure, we build it, and building control signs it off.

Kitchen extensions on Chislehurst semis and detached houses

A kitchen extension is one of the most common ways Chislehurst families gain space. On a semi or detached house the usual scheme is a single-storey rear extension across the back of the house, with the old rear wall opened on a steel beam so the kitchen, dining and family area become one room onto the garden. Wider plots also allow a side extension beside the house or a wraparound that joins the two. The work involves new foundations, a steel beam over the opening, and a roof, usually with rooflights or a lantern to bring light into the middle of the plan.

A single-storey rear extension often falls within permitted development, including in a conservation area, but that depends on your property, so it is never a given. Semi-detached houses get three metres of depth and detached houses four, or double that under the prior approval route. Side extensions and anything two storeys high lose permitted development in a conservation area, and earlier extensions count against the allowance, so those may need a planning application to Bromley Council. Where the new foundations run near a neighbour's house, the Party Wall Act applies too. We check the planning position first and tell you honestly which route your house needs before we start.

Housing in Chislehurst

Chislehurst has about 10,240 homes on the Council Tax list: 12% pre-1919, 19% interwar and 67% post-war, with flats making up 22% and houses 78%. 30% of homes here are detached; a detached house in Chislehurst often extends far enough from the boundary that no party wall notice is needed.

Planning a Chislehurst extension inside or near the conservation area

According to Bromley's Urban Design Guide SPD, a large part of Chislehurst falls within the Chislehurst Conservation Area, the largest in the borough. So the first thing to establish for a Chislehurst extension is whether the address is inside the boundary, because the planning route follows from that. Inside it, a side extension, a rear extension of more than one storey, any enlargement of the roof and cladding on the walls all need planning permission. A single storey rear extension within the normal limits can still be permitted development, unless an Article 4 direction for the address has removed that right.

Bromley says it cannot advise informally whether proposals fall within permitted development, so an answer comes in writing or not at all. Its written pre-application advice covers householder proposals, including extensions to an existing dwelling, and on a house in a conservation area it tests a design before the full application. For a two storey scheme, put Policy 8 into the first sketch: Bromley normally wants at least a 1 metre gap to the side boundary, kept for the whole height and length of the addition. On a narrow side garden that can decide whether an upper floor is possible at all.

Double storey extensions for Chislehurst homes

The detached houses and larger semis across Chislehurst often have room to grow both down and up, so we build double storey rear extensions that add a larger kitchen below and an extra bedroom or en-suite above. Deeper foundations carry the extra load, and steel beams tie the new structure back into the original walls. Matching the brick, the roof tiles and the roofline to the existing house matters as much as the space itself, in a post-war close as much as a period street.

A two storey extension is more likely to need planning permission than a modest single storey one, and we coordinate the application to Bromley Council where it is required. Every extension, whatever its size, must meet building regulations for foundations, structure, insulation and fire safety, inspected as the build progresses. We coordinate the trades and the fit-out so you deal with one team from the first drawing to the finished rooms.

Side return extensions in Chislehurst

Side returns belong to Victorian and Edwardian terraces, and only 12% of homes in Chislehurst predate 1919, so they are the exception here; most extensions run across the full rear width instead. Our side return extension page covers the build in detail, with build rates of £2,400 to £3,200 per m².

• Full fit-out, finishing and making good
• Side-return and rear extensions
• Levels, drainage and landscaping made good around the new build

VOA Council Tax stock of properties, March 2025, for Chislehurst North, Chislehurst West & Elmstead and Chislehurst East & Hoblingwell Wood. Counts rounded by the VOA.

For the wider picture around house extensions in Chislehurst, see RSJ and steel beam installation in Chislehurst, house extensions across Bromley, basement extensions, the Party Wall Act process for extensions, how we handle house extensions across London and Crittall Doors Guide.

The GS Renovation Difference in Chislehurst

Chislehurst homeowners choose GS Renovation because we build extensions that suit the house, not generic boxes. We advise honestly on whether your project is permitted development or needs a planning application to Bromley Council, plan the programme around any party wall notice you serve, and keep the brickwork sympathetic to BR7 streets. One team, led by a founder with 30+ years on the tools, handles groundworks, steel and finish.

• Weathertight shell reached before the fit-out begins
• Dust screens and floor protection in occupied homes
• Brick and mortar matched to the existing elevation

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.