Kitchen extensions with bedrooms above in Hayes

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

Postcode districts: UB3 and UB4
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: Hillingdon (1.7 miles), West Drayton (2.2 miles), Southall (2.3 miles)
First visit: Free, no obligation

About a kitchen extension with bedrooms above

This service suits you if your kitchen is too small and you also need another bedroom. Building both floors at once costs less than a single-storey kitchen extension now and a first floor later. You get a layout that works for cooking, eating and the garden, a bedroom plan that works upstairs, the approvals your nation needs and the build, carried out by vetted teams working under S&K. Kitchen units are priced separately.

We cover Hayes (UB3 and UB4) and the places around it, including Hillingdon (1.7 miles), West Drayton (2.2 miles) and Southall.

What it costs in Hayes

Guide prices for kitchen extensions with bedrooms above in London are around £2,400–£3,240 per m² of new floor space, including VAT. For a typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that's roughly £67,000–£90,500 (kitchen units and worktops priced separately). 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	£2,210–£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 Hayes

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 Hayes homes

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.

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.

How we'd run your project

Look at the house
We start in Hayes with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Drawings, then consent
We draw the scheme, check it against the rules in England, and take it through the right consent with the council.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
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 Hayes

How much does a kitchen extension with bedrooms above cost in Hayes?

Our guide for London, which covers Hayes, is £2,400–£3,240 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £67,000–£90,500 (kitchen units and worktops priced separately). Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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

Hayes 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 Hayes?

We cover Hayes (UB3 and UB4) and nearby places including Hillingdon, West Drayton and Southall, plus the rest of Greater London. The first site visit is free.

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

We also cover places near Hayes, including:

Other extensions in Hayes

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

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