Extensions in Chislehurst: design, planning and build
Looking to extend your home in Chislehurst? Start here: extension types, guide prices for Chislehurst, the planning rules that apply and how a project runs.
- Postcode districtsBR7
- Price regionLondon (×1.3)
- Planning rulesEngland
- Site visitFree, no obligation
Which extension suits a Chislehurst home?
Across London, terraced houses with narrow side returns and tight access are the norm, which shapes everything from party wall notices to how materials reach the back garden.
The types we would usually look at first for a home in Chislehurst are glass box extensions, kitchen extensions and side return extensions, depending on the garden and how the house is laid out.
Popular extension prices in Chislehurst
Prices on this page use our London factor of ×1.3, include VAT at 20% and cover the build; your written price follows a survey and agreed drawings.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Double-storey extensions | 32 m² | £74,500 – £98,000 |
| Extensions over a garage | 12 m² | £32,500 – £42,500 |
| Kitchen extensions | 20 m² | £54,500 – £69,000 |
| Side return extensions | 11 m² | £34,000 – £43,000 |
| Wraparound extensions | 25 m² | £74,500 – £94,500 |
| Single-storey rear extensions | 20 m² | £53,000 – £68,000 |
| Conservatory replacement extensions | 14 m² | £39,000 – £50,500 |
Chislehurst and surrounding towns
Our survey diary covers Chislehurst, including BR7. The same team covers Eltham (2 miles), Orpington (3 miles), Welling (4 miles), Bexley (4 miles), Beckenham (4 miles), all within easy reach. Just over the Kent border, Swanley is about 5 miles away.
Do extensions in Chislehurst need planning permission?
In England a single-storey rear extension can usually go up to 3 m beyond the original rear wall of a semi-detached or terraced house, or 4 m on a detached house, without a planning application, provided it is no more than 4 m high, keeps eaves to 3 m within 2 m of a boundary and, with other buildings, covers no more than half the land around the original house. The larger home extension prior approval scheme raises those depths to 6 m and 8 m, with neighbours notified and a 42-day decision.
In England a single-storey side extension can be permitted development if it is no more than 4 m high and no wider than half the width of the original house. Two-storey side extensions, and any side extension on designated land such as a conservation area, need a householder planning application.
In a conservation area, national park, National Landscape, the Broads or a World Heritage Site the permitted development limits are tighter (no side or two-storey extensions without an application). Listed homes need listed building consent, and if permitted development rights have been removed, any extension needs an application.
Building regulations approval is separate from planning. In England you can use the council's building control team or a registered building control approver; a full plans application gets the drawings checked before work starts, and the inspector signs the work off with a completion certificate.
Applications are decided by the local planning authority (your district, borough or unitary council).
Every extension type in Chislehurst
- Single-storey rear extensions · from £27,000
- Home office extensions · from £20,500
- Planning permission for extensions · from £450
- Bedroom extensions · from £33,500
- Timber frame extensions · from £27,000
- Wraparound extensions · from £46,500
- Side extensions · from £28,500
- Utility and boot room extensions · from £18,000
- Kitchen extensions · from £35,000
- Double-storey extensions · from £49,000
- Building regulations for extensions · from £1,150
- Annexe extensions · from £71,500
- Side return extensions · from £23,000
- Extensions over a garage · from £31,000
- Pitched roof extensions · from £28,500
- Orangery extensions · from £39,000
- Extension plans and drawings · from £1,550
- Porch extensions · from £5,200
- Flat roof extensions · from £27,000
- Conservatory replacement extensions · from £26,000
- Bungalow extensions · from £34,000
- Glass box extensions · from £39,000
Free site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Questions about extensions in Chislehurst
How much does an extension cost in Chislehurst?
Using our London factor (×1.3), a standard-spec single-storey extension of 20 m² is a guide £53,000 to £68,000 including VAT, and a 32 m² two-storey extension £74,500 to £98,000. Your written price follows the survey.
Who do I contract with?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Will my neighbours need to be told?
If you apply for planning or prior approval the council notifies them, and in England party wall notices may be needed for work near a shared boundary.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Chislehurst, and the guide-price tool gives a range for your own size and finish in about a minute.
How long does an extension take in Chislehurst?
Usually 2 to 4 months of design and approvals, then 10 to 16 weeks on site for a single-storey extension or 16 to 24 weeks for two storeys.
Book a free site visit in Chislehurst
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.