Kitchen extensions with bedrooms above in Harrow
If you live in Harrow and need more room without moving, a kitchen extension with bedrooms above is worth a serious look. We handle the drawings, approvals, structure and build.
Before you start in Harrow, here's what applies.
- Postcode districts
- HA1
- 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
- Harrow on the Hill (0.5 miles), Wealdstone (1.5 miles), Sudbury (Greater London) (1.6 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.
Around Harrow we also work in Harrow on the Hill, Wealdstone and Sudbury (Greater London), and across the rest of Greater London. Postcode district in and near Harrow: HA1.
What it costs in Harrow
In London, which includes Harrow, we'd expect a kitchen extension with bedrooms above to cost 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), or £2,400–£3,240 per m² including VAT. Design fees, structural calculations and approval fees are separate and listed on our prices page.
| 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 Harrow
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 Harrow homes
Services and drainage
Sinks, dishwashers and an upstairs bathroom all need waste routes to the drains, often near where the extension goes. We check the drains early and plan soil stacks, gas and electrical supplies so the kitchen layout is not limited later.
Glazing and the Part L 25% rule
In England, new windows, roof lights and glazed doors in an extension are normally limited to 25% of the extension's floor area plus the area of any windows or doors removed. Larger glazing is possible, but needs SAP or compensating calculations, so we plan the rear doors around this from the start.
How we'd run your project
Look at the house
We start in Harrow with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in England before drawing in detail.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.
Questions about kitchen extensions with bedrooms above in Harrow
Who handles building regulations for a project in Harrow?
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 Harrow?
Harrow 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.
How long does a kitchen extension with bedrooms above take?
Allow 4 to 8 weeks for survey and design, then the approval period (councils should decide householder applications within 8 weeks of validation), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.
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
We also cover places near Harrow, including:
Other extensions in Harrow
All two-storey extension services in Harrow · Kitchen extensions with bedrooms above across Greater London
The quickest next step is a visit. We'll look at your house in Harrow and give you an honest view of the options.