house-extension.uk

Bedroom extensions for homes in Greater London

We design and build bedroom extensions for houses in Greater London, with a written price once the survey and design are done and one point of contact throughout.

  • Guide priceFrom £33,500 inc VAT
  • PlanningUsually a householder application
  • Towns covered105
  • Site visitFree, no obligation
Bedroom in an extension with a roof window and an en-suite shower room

Extensions in and around Greater London

Towns we cover in Greater London include Bexley, Barking, Sutton, Croydon, Ilford, Enfield, Harrow, Tottenham. 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.

How much does a bedroom extension cost in Greater London?

Prices below are for Greater London, using the London factor of ×1.3. They are guide ranges including VAT for the build only, not a quote.

Typical rates in Greater London: £2,080 to £4,160 per m² including VAT, depending on specification.

SizeEssentialStandardPremium
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.

Planning rules that apply in Greater London

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.

Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.

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.

If the work involves a shared wall, building on the boundary, or digging foundations within 3 m (sometimes 6 m) of a neighbour's building, the Party Wall etc. Act 1996 applies and notice must be served before work starts: two months for work to a party wall, one month for new walls on the boundary and for excavations.

Applications are decided by the local planning authority (your district, borough or unitary council).

What we take care of

  • Heating extended to the new rooms
  • Planning drawings and application
  • Fire safety: escape windows and smoke alarms to building regulations
  • Structure, roof, insulation and finish
  • Layout options: two-storey, over-garage or ground floor
  • En-suite drainage and ventilation design

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.

  1. Free site visit

    It starts with a visit to your house to measure, check access and talk through ideas and budget.

  2. 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.

  3. Fixed written price

    You receive a written, itemised price and programme. Nothing starts until you are happy with it.

  4. Build and sign-off

    We build it with one project manager, book the building control inspections and hand over the completion certificate.

Your questions about a bedroom extension in Greater London

Can I see a price before committing to anything?

Yes. The guide prices on this page are adjusted for Greater London, 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 you cover all of Greater London?

Yes, across the whole of Greater London. Site visits are free and there is no obligation.

Do I need building regulations approval in Greater London?

Yes. Almost every extension needs it, whatever the planning route. We prepare the drawings and book the inspections.

Will a new bedroom need planning permission?

Upstairs additions usually do. Ground-floor rooms may fall within permitted development, depending on size and position.

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 Greater London

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 .

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