Blackburn · Lancashire

Kitchen extensions with bedrooms above in Blackburn

For a kitchen extension with bedrooms above in Blackburn, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Lancashire.

Blackburn: the key facts for this kind of project.

Postcode districts
BB1 and BB2
County / area
Lancashire, England
Price region
North West England
Guide price
£53,000–£72,000 (£1,900–£2,560 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
Darwen (3.7 miles), Great Harwood (3.9 miles), Accrington (5.1 miles)
Distance to Preston
about 9.1 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 Blackburn (BB1 and BB2) and the places around it, including Darwen (3.7 miles), Great Harwood (3.9 miles) and Accrington.

What it costs in Blackburn

A guide price for Blackburn: around £53,000–£72,000 (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 £1,900–£2,560 per m² of new floor space, including VAT at 20%. Professional fees for drawings and the structural engineer are listed separately on our prices page.

SpecPer m²A 4 m × 3.5 m footprint on two floors (28 m² of new floor space)
Essential£1,750–£2,360 per m²£49,000–£66,000
Standard£1,900–£2,560 per m²£53,000–£72,000
Premium£2,280–£3,080 per m²£64,000–£86,000

Planning and building regulations in Blackburn

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 Blackburn 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

  1. Understand the brief

    At your home in Blackburn 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 Blackburn and deal with any questions from the planning officer.

  3. Structure and building control

    A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.

  4. Build and hand over

    We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about kitchen extensions with bedrooms above in Blackburn

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.

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

Our guide for North West England, which covers Blackburn, is £1,900–£2,560 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 £53,000–£72,000 (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 Blackburn?

We cover Blackburn (BB1 and BB2) and nearby places including Darwen, Great Harwood and Accrington, plus the rest of Lancashire. 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

Close to Blackburn? We work across the area, including:

Other extensions in Blackburn

All two-storey extension services in Blackburn · Kitchen extensions with bedrooms above across Lancashire

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