Extensions over a garage in Chelmsley Wood

Before you start in Chelmsley Wood, here's what applies.

Postcode districts: B33, B37 and B40
County / area: West Midlands, England
Price region: West Midlands
Guide price: £31,500–£46,000 (£1,750–£2,550 per m²)
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Nearest towns: Castle Vale (3.7 miles), Acocks Green (3.8 miles), Washwood Heath (4 miles)
Distance to Birmingham: about 6.8 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.

We cover postcode districts B33, B37 and B40 in and around Chelmsley Wood, along with neighbouring Castle Vale, Acocks Green and Washwood Heath.

What it costs in Chelmsley Wood

A guide price for Chelmsley Wood: around £31,500–£46,000 for 3 m × 6 m of new first-floor space (18 m²). That works out at £1,750–£2,550 per m² of new floor space, including VAT at 20%. Steelwork for wide openings is the item most likely to move the figure; we'll know once the engineer has designed it.

Spec	Per m²	3 m × 6 m of new first-floor space (18 m²)
Essential	£1,610–£2,350 per m²	£29,000–£42,000
Standard	£1,750–£2,550 per m²	£31,500–£46,000
Premium	£2,100–£3,060 per m²	£38,000–£55,000

Planning and building regulations in Chelmsley Wood

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 Chelmsley Wood 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 Chelmsley Wood with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Get it approved
Once you're happy with the design we submit it to the council for Chelmsley Wood and deal with any questions from the planning officer.
Structure and building control
A structural engineer sizes the foundations and steels, and we get building regulations approval before work starts.
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 Chelmsley Wood

Who handles building regulations for a project in Chelmsley Wood?

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 much does an extension over a garage cost in Chelmsley Wood?

Our guide for the West Midlands, which covers Chelmsley Wood, is £1,750–£2,550 per m² including VAT. A typical project with 3 m × 6 m of new first-floor space (18 m²) comes to about £31,500–£46,000. 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.

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.

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

Nearby towns we cover for extensions over a garage:

Other extensions in Chelmsley Wood

All two-storey extension services in Chelmsley Wood · Extensions over a garage across the West Midlands

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Chelmsley Wood.