Wraparound extensions in Beckenham: design, approvals and build
From the first sketch to final sign-off, we plan and build wraparound extensions in Beckenham and the surrounding Greater London area.
- Guide price in BeckenhamFrom £46,500 inc VAT
- PlanningUsually a householder application
- Build time14–20 weeks on site
- Postcode districtsBR1, BR3, SE6, SE20, SE25
Is a wraparound extension right for your house?
- Semi-detached houses with a side passage
- Families who want kitchen, dining and living in one space
- Terraced houses that want the largest ground floor possible
The corner is where wraparounds succeed or fail. We usually use a single steel goalpost or a corner post hidden in a pier, and set the glazing so the new room reads as one space rather than two boxes.
Covering Beckenham
We cover Beckenham and the postcode districts BR1, BR3, SE6, SE20, SE25, SE26. Neighbouring towns we cover include South Norwood (2 miles), Catford (3 miles), Upper Norwood (3 miles), Croydon (4 miles).
For homes towards Kent, Swanley is around 9 miles away. 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.
Planning and approvals in Beckenham
In England a wraparound extension is assessed as both a side and a rear extension, and the combination usually falls outside permitted development, so most need a householder planning application (£548 from 1 April 2026).
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 over or within 3 m of a public sewer needs the water company's consent, usually through a build-over agreement, before the foundations go in.
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).
Guide prices for Beckenham
For Beckenham we adjust our national guide rates by ×1.3, the factor we use for London. Figures include VAT; your written quote after the survey replaces them.
Typical rates in Beckenham: £2,600 to £4,810 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Compact L-shape 18 m² | £46,500 – £56,500 | £53,500 – £68,000 | £67,500 – £87,000 |
| Medium L-shape 25 m² | £65,000 – £78,000 | £74,500 – £94,500 | £94,000 – £120,500 |
| Large L-shape 32 m² | £83,000 – £100,000 | £95,500 – £121,000 | £120,500 – £154,000 |
For a figure based on your own dimensions, use our guide-price tool.
Our process, step by step
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Beckenham home, measure up, talk through what you want and check the planning position.
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.
Common questions in Beckenham
How long does a wraparound extension take to build in Beckenham?
On site, typically 14 to 20 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Do I need building regulations approval in Beckenham?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Beckenham, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do wraparound extensions need planning permission?
Usually, yes. In England the side element counts as a side extension and the rear element as a rear extension, and the combination normally falls outside permitted development. A householder application costs £548 in England from 1 April 2026.
Will I need to move a drain?
Often. Side returns frequently contain a manhole or a shared drain. Building near or over a public sewer needs the water company’s consent in England and Wales, which we arrange.
Book a free site visit in Beckenham
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.