Kitchen extensions with bedrooms above in Collier Row
Want to stay in Collier Row but need more space? A kitchen extension with bedrooms above adds floor area on two levels without giving up much garden. Here's what's involved.
Collier Row: the key facts for this kind of project.
- Postcode districts
- RM5
- 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
- Romford (1.8 miles), Chadwell Heath (2.4 miles), Harold Wood (2.9 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 Collier Row (RM5) and the places around it, including Romford (1.8 miles), Chadwell Heath (2.4 miles) and Harold Wood.
What it costs in Collier Row
Most of the cost of a kitchen extension with bedrooms above is set by its size and specification. For Collier Row and the rest of London, our guide is £2,400–£3,240 per m² including VAT, so about £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). Keep a contingency of around 10% for things nobody can see until the ground is opened up.
| 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 Collier Row
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 Collier Row homes
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.
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 Collier Row 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.
Engineer it
Foundations sized for two floors, steels for any openings, and building control approval, all before anyone starts on site.
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 Collier Row
How much does a kitchen extension with bedrooms above cost in Collier Row?
Our guide for London, which covers Collier Row, 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 Collier Row?
Collier Row 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 Collier Row?
We cover Collier Row (RM5) and nearby places including Romford, Chadwell Heath and Harold Wood, 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 Collier Row, including:
Other extensions in Collier Row
All two-storey extension services in Collier Row · Kitchen extensions with bedrooms above across Greater London
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Collier Row.