Bedroom extensions in Orpington
From the first sketch to final sign-off, we plan and build bedroom extensions in Orpington and the surrounding Greater London area.
- Guide price in OrpingtonFrom £33,500 inc VAT
- PlanningUsually a householder application
- Build time14–22 weeks on site
- Postcode districtsBR5, BR6

Do I need planning permission in Orpington?
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.
Homes in conservation areas, national parks, National Landscapes (formerly AONBs), the Broads and World Heritage Sites have tighter rules, so we always check the property's status and planning history before design starts.
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.
Applications are decided by the local planning authority (your district, borough or unitary council).
How much does a bedroom extension cost in Orpington?
For Orpington 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 Orpington: £2,080 to £4,160 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| One bedroom 12 m² | £33,500 – £41,500 | £33,500 – £44,000 | £37,000 – £50,000 |
| Bedroom and en-suite 18 m² | £37,000 – £46,000 | £44,000 – £57,500 | £56,000 – £75,000 |
| Two rooms 30 m² | £62,000 – £76,500 | £74,000 – £96,000 | £93,500 – £125,000 |
Try the guide-price tool to see a range for your own size and finish.
Extensions in and around Orpington
Across BR5, BR6, we can visit, measure and advise. We also work in nearby Chislehurst (3 miles), Bexley (5 miles), Eltham (6 miles), Beckenham (6 miles).
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.
What we take care of
- Layout options: two-storey, over-garage or ground floor
- Structure, roof, insulation and finish
- En-suite drainage and ventilation design
- Planning drawings and application
From first visit to completion
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Bedroom extension questions answered
How long does a bedroom extension take to build in Orpington?
On site, typically 14 to 22 weeks once approvals are in place. Before that, allow 8–14 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Orpington, 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 I need building regulations approval in Orpington?
Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.
Does an en-suite need a window?
No, but it needs mechanical extraction that meets the building regulations. We design the duct route at the drawing stage.
Can I add a ground-floor bedroom for a relative?
Yes. A ground-floor bedroom with an accessible shower room is a common request. If it will be lived in as a self-contained home, planning treats it differently, so tell us how it will be used.
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.