Extending your home in Streatham
Every type of house extension in Streatham, from single-storey kitchen extensions to two-storey additions, side returns and orangeries. We design, handle the approvals and build.
- Postcode districtsCR4, SE27, SW2, SW12, SW16, SW17
- Price regionLondon (×1.3)
- Planning rulesEngland
- Site visitFree, no obligation
Which extension suits a Streatham 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 Streatham are side return extensions, wraparound extensions and kitchen extensions, depending on the garden and how the house is laid out.
Do extensions in Streatham 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 two-storey rear extension is permitted development only if it projects no more than 3 m from the original rear wall, sits at least 7 m from the rear boundary, matches the roof pitch and uses obscure, non-opening side windows upstairs. Most two-storey extensions therefore go through a householder planning application, which costs £548 from 1 April 2026 and normally takes about 8 weeks.
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).
Popular extension prices in Streatham
We publish guide prices so you can budget before anyone visits. For Streatham they are adjusted by ×1.3, the factor we use across London.
| Extension type | Example size | Standard spec (inc VAT) |
|---|---|---|
| Extensions over a garage | 12 m² | £32,500 – £42,500 |
| Wraparound extensions | 25 m² | £74,500 – £94,500 |
| Side return extensions | 11 m² | £34,000 – £43,000 |
| Double-storey extensions | 32 m² | £74,500 – £98,000 |
| Orangery extensions | 16 m² | £58,000 – £73,000 |
Covering Streatham and nearby
Postcode districts we cover around Streatham include CR4, SE27, SW2, SW12, SW16, SW17. Nearby, we also take on projects in Norbury (1 mile), Tooting (1 mile), Upper Norwood (2 miles), Mitcham (2 miles), Earlsfield (3 miles). Ewell, in Surrey, is roughly 7 miles from Streatham and also on our list.
Choose an extension type
- Home office extensions · from £20,500
- Flat roof extensions · from £27,000
- Utility and boot room extensions · from £18,000
- Double-storey extensions · from £49,000
- Glass box extensions · from £39,000
- Kitchen extensions · from £35,000
- Side extensions · from £28,500
- Conservatory replacement extensions · from £26,000
- Building regulations for extensions · from £1,150
- Orangery extensions · from £39,000
- Pitched roof extensions · from £28,500
- Bungalow extensions · from £34,000
- Single-storey rear extensions · from £27,000
- Extensions over a garage · from £31,000
- Annexe extensions · from £71,500
- Bedroom extensions · from £33,500
- Wraparound extensions · from £46,500
- Planning permission for extensions · from £450
- Side return extensions · from £23,000
- Porch extensions · from £5,200
- Timber frame extensions · from £27,000
- Extension plans and drawings · from £1,550
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions about extensions in Streatham
How much does an extension cost in Streatham?
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.
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.
Do you cover all of Streatham?
Yes, including the surrounding parts of Greater London. Site visits are free and there is no obligation.
Do I need planning permission for an extension in Streatham?
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.
Can I get a price before anyone visits?
Yes. This page shows guide prices adjusted for Streatham, and the guide-price tool gives a range for your own size and finish in about a minute.
Book a free site visit in Streatham
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.