Extensions over a garage in Great Harwood

What we'd confirm first for a project in Great Harwood.

Postcode districts: BB6
County / area: Lancashire, 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: Accrington (3 miles), Blackburn (3.9 miles), Padiham (4 miles)
Distance to Preston: about 12.2 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 Great Harwood we also work in Accrington, Blackburn and Padiham, and across the rest of Lancashire. Postcode district in and near Great Harwood: BB6.

What it costs in Great Harwood

A guide price for Great Harwood: 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%. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

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 Great Harwood

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 Great Harwood 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.

Garage walls and the door opening

Garage walls are often a single skin of brick or block with piers, and the wide door opening needs a beam over it. Many over-garage extensions need new inner walls or a steel frame to carry the floor and to insulate properly, which we confirm before the design is fixed.

How we'd run your project

Start at your house
We come to your home in Great Harwood, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Great Harwood.
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 extensions over a garage in Great Harwood

Do I need planning permission for an extension over a garage in Great Harwood?

Great Harwood is in England, so England planning rules apply. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side. If in doubt, a lawful development certificate or a planning application gives you certainty before you build.

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.

Who handles building regulations for a project in Great Harwood?

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.

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.

Can my garage take a room on top?

Sometimes, but it needs checking. Many garages are built on shallow footings with thin walls, designed only for a single storey. We dig a trial hole and inspect the walls, and the structural engineer decides whether to reuse them, strengthen them, underpin the footings or build new foundations inside the garage.

Nearby

Close to Great Harwood? We work across the area, including:

Other extensions in Great Harwood

All two-storey extension services in Great Harwood · Extensions over a garage across Lancashire

Tell us about your house in Great Harwood and we'll call you back to arrange a free, no-obligation visit.