Kitchen extensions with bedrooms above in Swanley

Before you start in Swanley, here's what applies.

Postcode districts: BR8 and DA4
County / area: Kent, England
Price region: South East England
Guide price: £61,500–£83,000 (£2,200–£2,970 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: Bexley (3.2 miles), Chelsfield (3.3 miles), Orpington (3.6 miles)
Distance to Maidstone: about 17.4 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 Swanley (BR8 and DA4) and the places around it, including Bexley (3.2 miles), Chelsfield (3.3 miles) and Orpington.

What it costs in Swanley

Using our South East England rates, a kitchen extension with bedrooms above with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £61,500–£83,000 (kitchen units and worktops priced separately), including VAT. Bigger or more glazed designs cost more per m². These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

Spec	Per m²	A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential	£2,020–£2,730 per m²	£56,500–£76,500
Standard	£2,200–£2,970 per m²	£61,500–£83,000
Premium	£2,640–£3,560 per m²	£74,000–£100,000

Planning and building regulations in Swanley

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 Swanley 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

Look at the house
We start in Swanley with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
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 Swanley

Which postcodes do you cover around Swanley?

We cover Swanley (BR8 and DA4) and nearby places including Bexley, Chelsfield and Orpington, plus the rest of Kent. The first site visit is free.

Who handles building regulations for a project in Swanley?

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.

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

Swanley 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.

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.

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.

Nearby

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Tell us about your house in Swanley and we'll call you back to arrange a free, no-obligation visit.