Chelsfield · Greater London

Kitchen extensions with bedrooms above in Chelsfield

For a kitchen extension with bedrooms above in Chelsfield, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Greater London.

Useful details for planning a kitchen extension with bedrooms above in Chelsfield.

Postcode districts
BR6
County / area
Greater London, England
Price region
London
Guide price
£67,000–£90,500 (£2,400–£3,240 per m²), kitchen units and worktops priced separately
Approval route
It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission.
Nearest towns
Orpington (1.7 miles), Farnborough (Greater London) (2.5 miles), Swanley (3.3 miles)
First visit
Free, no obligation

About a kitchen extension with bedrooms above

A kitchen extension with bedrooms above is a two-storey extension designed so the ground floor becomes a larger, usually open-plan kitchen and dining space, with one or two bedrooms or a bathroom on the first floor. It is a natural fit for a two-storey rear extension. The key design issues are the steel beams that open up the house, glazing and ventilation.

We cover Chelsfield (BR6) and the places around it, including Orpington (1.7 miles), Farnborough (Greater London) (2.5 miles) and Swanley.

What it costs in Chelsfield

A guide price for Chelsfield: around £67,000–£90,500 (kitchen units and worktops priced separately) for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). That works out at £2,400–£3,240 per m² of new floor space, including VAT at 20%. Keep a contingency of around 10% for things nobody can see until the ground is opened up.

SpecPer m²A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential£2,210–£2,980 per m²£62,000–£83,500
Standard£2,400–£3,240 per m²£67,000–£90,500
Premium£2,880–£3,890 per m²£80,500–£109,000

Planning and building regulations in Chelsfield

In England, a two-storey rear kitchen extension can be permitted development if it goes no more than 3 m beyond the rear wall of the original house and stays at least 7 m from the rear boundary, with matching materials and roof pitch, outside protected areas. No balconies are allowed. Deeper designs need planning permission, costing £548 (or £575 for applications made from 8 December 2026).

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

Design points for Chelsfield homes

Bedrooms over a kitchen

Bedrooms above need an escape window or a protected route to the stairs, plus good sound insulation from the kitchen below. We position the stairs, landing and bedroom doors so the new rooms connect naturally to the existing first floor.

Steel beams and the open-plan opening

Removing the old rear wall to make one large room means a steel beam, sometimes several, to carry the first floor and roof. The engineer sizes the steel and its supports, and we decide early whether you want a flush ceiling with the beam hidden or a downstand, as this affects ceiling heights.

How we'd run your project

  1. Measure and listen

    A visit to Chelsfield to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.

  2. Get it approved

    Once you're happy with the design we submit it to the council for Chelsfield and deal with any questions from the planning officer.

  3. Structure and building control

    A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.

  4. Finish and certify

    Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about kitchen extensions with bedrooms above in Chelsfield

Do I need planning permission for a kitchen extension with bedrooms above in Chelsfield?

Chelsfield is in England, so England planning rules apply. It may be permitted development if it goes no more than 3 m beyond the original rear wall (counting any single-storey part) and stays 7 m from the rear boundary; otherwise it needs planning permission. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

Which postcodes do you cover around Chelsfield?

We cover Chelsfield (BR6) and nearby places including Orpington, Farnborough (Greater London) and Swanley, plus the rest of Greater London. The first site visit is free.

Who handles building regulations for a project in Chelsfield?

We handle it as part of the project. What's needed in England: building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

Is it cheaper to build a kitchen extension and bedrooms at the same time?

Yes, in most cases. Building both floors at once means one set of foundations, one roof, one scaffold and one set of approvals. Adding a first floor later means removing the original roof, possibly strengthening the foundations and disrupting the kitchen again. If you think you will need the bedroom, build it now.

Can I keep using my kitchen during the build?

For part of it. The new structure can be built while your existing kitchen stays in use, but when the rear wall is opened and the new kitchen is fitted there will be several weeks without one. We plan when this happens and help you set up a temporary kitchen elsewhere in the house.

Nearby

Nearby towns we cover for kitchen extensions with bedrooms above:

Other extensions in Chelsfield

All two-storey extension services in Chelsfield · Kitchen extensions with bedrooms above across Greater London

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