Extensions over a garage in Kearsley

Useful details for planning an extension over a garage in Kearsley.

Postcode districts: BL4
County / area: Greater Manchester, England
Price region: North West England
Guide price: £30,000–£43,500 (£1,660–£2,420 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Walkden (1.3 miles), Farnworth (1.3 miles), Little Hulton (1.4 miles)
Distance to Manchester: about 7 miles
First visit: Free, no obligation

About an extension over a garage

An extension over a garage is a new first-floor room built on top of an existing attached garage, usually a bedroom, en-suite or study. It uses a footprint you already have, so it adds floor space without taking any garden. The garage walls and foundations often need strengthening or replacing to carry the new floor.

Around Kearsley we also work in Walkden, Farnworth and Little Hulton, and across the rest of Greater Manchester. Postcode district in and near Kearsley: BL4.

What it costs in Kearsley

A guide price for Kearsley: around £30,000–£43,500 for 3 m × 6 m of new first-floor space (18 m²). That works out at £1,660–£2,420 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.

Spec	Per m²	3 m × 6 m of new first-floor space (18 m²)
Essential	£1,530–£2,230 per m²	£27,500–£40,000
Standard	£1,660–£2,420 per m²	£30,000–£43,500
Premium	£1,990–£2,910 per m²	£36,000–£52,500

Planning and building regulations in Kearsley

In England, most garages sit beside the house, so building over one makes a two-storey extension beyond a side wall, which always needs planning permission. If the garage is at the rear, the 3 m and 7 m rules for two-storey rear extensions apply, measured from the original house. A householder application costs £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 Kearsley homes

Matching the house

A room over a garage usually sits beside the front of the house in full view, so roof form, ridge height, windows and brick matter. Setting the front wall and ridge back slightly from the main house usually helps it look as if it belongs.

Fire separation

If the garage stays a garage, the floor between it and the room above, and any door into the house, must give fire separation under building regulations. That usually means fire-resisting plasterboard ceilings, sealed gaps and a fire door, which we design in from the start.

How we'd run your project

Look at the house
We start in Kearsley with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Kearsley.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Questions about extensions over a garage in Kearsley

How much does an extension over a garage cost in Kearsley?

Our guide for North West England, which covers Kearsley, is £1,660–£2,420 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £30,000–£43,500. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

How long does an extension over a garage 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.

Which postcodes do you cover around Kearsley?

We cover Kearsley (BL4) and nearby places including Walkden, Farnworth and Little Hulton, plus the rest of Greater Manchester. The first site visit is free.

Do I need to convert the garage as well?

No. You can keep the garage for parking or storage and build only the room above, as long as the floor between them and any door into the house meet fire separation rules. Converting the garage at the same time is often good value, because the walls and foundations may be upgraded anyway.

How do I get into a room over the garage?

Usually through a new opening off the existing landing or a bedroom, so the stairs stay where they are. If the floor levels do not match, a step or two may be needed inside the new room. Where a landing opening is not practical, a new stair from a converted garage is an option.

Nearby

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

Other extensions in Kearsley

All two-storey extension services in Kearsley · Extensions over a garage across Greater Manchester

Want a figure first? Try our guide price tool, then book a free visit to firm it up.