Keynsham · Somerset

Kitchen extensions with bedrooms above in Keynsham

Want to stay in Keynsham 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.

The basics for Keynsham at a glance.

Postcode districts
BS31
County / area
Somerset, England
Price region
South West England
Guide price
£57,500–£78,000 (£2,060–£2,780 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
Kingswood (2.7 miles), Whitchurch (Bristol) (2.8 miles), Publow (3.1 miles)
Distance to Bath
about 6.5 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.

Keynsham sits about 6.5 miles from Bath. Closer to home, Kingswood is 2.7 miles away and Whitchurch (Bristol) 2.8 miles.

What it costs in Keynsham

A guide price for Keynsham: around £57,500–£78,000 (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 £2,060–£2,780 per m² of new floor space, including VAT at 20%. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

SpecPer m²A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential£1,900–£2,560 per m²£53,000–£71,500
Standard£2,060–£2,780 per m²£57,500–£78,000
Premium£2,470–£3,340 per m²£69,000–£93,500

Planning and building regulations in Keynsham

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 Keynsham 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.

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

  1. Understand the brief

    At your home in Keynsham we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.

  2. Get it approved

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

  3. Detail and price

    Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.

  4. Build

    Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.

Questions about kitchen extensions with bedrooms above in Keynsham

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

Keynsham 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 much does a kitchen extension with bedrooms above cost in Keynsham?

Our guide for South West England, which covers Keynsham, is £2,060–£2,780 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 £57,500–£78,000 (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.

Which postcodes do you cover around Keynsham?

We cover Keynsham (BS31) and nearby places including Kingswood, Whitchurch (Bristol) and Publow, plus the rest of Somerset. The first site visit is free.

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 Keynsham

All two-storey extension services in Keynsham · Kitchen extensions with bedrooms above across Somerset

Book a free site visit in Keynsham and we'll tell you what's possible, what approvals you need and what the design stage would cost.

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