Extensions in Orpington: design, planning and build
Every type of house extension in Orpington, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsBR5, BR6
- Price regionLondon (×1.3)
- Planning rulesEngland
- Site visitFree, no obligation
Popular extension prices in Orpington
We publish guide prices so you can budget before anyone visits. For Orpington they are adjusted by ×1.3, the factor we use across London.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Kitchen extensions | 20 m² | £54,500 – £69,000 |
| Extensions over a garage | 12 m² | £32,500 – £42,500 |
| Side return extensions | 11 m² | £34,000 – £43,000 |
| Double-storey extensions | 32 m² | £74,500 – £98,000 |
| Single-storey rear extensions | 20 m² | £53,000 – £68,000 |
| Wraparound extensions | 25 m² | £74,500 – £94,500 |
| Orangery extensions | 16 m² | £58,000 – £73,000 |
Approvals for an extension in Orpington
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 return infill is often permitted development if it stays within the height limits and is no wider than half the width of the original house. Conservation areas, listed buildings and flats always need an application, and the boundary wall usually brings in the Party Wall Act.
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).
Choosing the right extension in Orpington
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.
Depending on the plot, side return extensions and kitchen extensions are often the strongest options, with glass box extensions worth considering where there is room.
Where we work near Orpington
Site visits are available across Orpington (BR5, BR6). Nearby, we also take on projects in Chislehurst (3 miles), Bexley (5 miles), Eltham (6 miles), Beckenham (6 miles), Welling (6 miles). For homes towards Kent, Swanley is around 4 miles away.
Choose an extension type
- Wraparound extensions · from £46,500
- Conservatory replacement extensions · from £26,000
- Timber frame extensions · from £27,000
- Annexe extensions · from £71,500
- Double-storey extensions · from £49,000
- Side return extensions · from £23,000
- Extension plans and drawings · from £1,550
- Planning permission for extensions · from £450
- Bedroom extensions · from £33,500
- Home office extensions · from £20,500
- Kitchen extensions · from £35,000
- Glass box extensions · from £39,000
- Side extensions · from £28,500
- Single-storey rear extensions · from £27,000
- Utility and boot room extensions · from £18,000
- Bungalow extensions · from £34,000
- Building regulations for extensions · from £1,150
- Flat roof extensions · from £27,000
- Pitched roof extensions · from £28,500
- Porch extensions · from £5,200
- Extensions over a garage · from £31,000
- Orangery extensions · from £39,000
Free site visit
We visit your Orpington home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Questions about extensions in Orpington
How much does an extension cost in Orpington?
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.
Do you handle building regulations?
Yes. We prepare the drawings and calculations, submit them and book inspections, ending with a completion certificate.
Do I need planning permission for an extension in Orpington?
Not always. It depends on the size, position and your property's history. Many single-storey rear extensions in England are permitted development or can use prior approval.
Do you cover all of Orpington?
Yes, including the surrounding parts of Greater London. Site visits are free and there is no obligation.
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.
Book a free site visit in Orpington
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.