Extensions over a garage in the West Midlands

West Midlands at a glance

Nation: England
Price region: West Midlands
Postcode areas: B, CV, DY, WS, WV
Towns covered: 33 listed below, plus surrounding villages
Approval route: Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.
Site visits: Free, no obligation

What an extension over a garage involves

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.

Across West Midlands we cover Birmingham (B1), Coventry (CV1), Wolverhampton (WV1), Dudley (DY1), Walsall (WS1) and Solihull (B91), plus the smaller places around them.

Guide price in the West Midlands

For budgeting in the West Midlands, allow around £31,500–£46,000 for an extension over a garage with 3 m × 6 m of new first-floor space (18 m²). That's based on £1,750–£2,550 per m² including VAT for the West Midlands. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

Spec	Per m²	Typical project
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

Rules in England

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.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

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.

Floor levels and headroom

Garage floors are often lower than the house, and the new first floor may not line up with the existing landing. We set the floor level to avoid awkward steps upstairs, while keeping enough headroom in the garage below for a car or storage.

How we work in the West Midlands

Visit and first ideas
One of our team visits your house in the West Midlands, checks the walls, roof and drains, and sketches out options with you.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Detail and price
Construction drawings, engineer's calculations and building control sign-off, then a written fixed price for the build.
Build
Foundations, walls, floor, roof, windows, then first and second fix. We break through into the house as late as we can.

Towns we cover in the West Midlands

Extensions over a garage in the West Midlands: questions

How much does an extension over a garage cost in the West Midlands?

In the West Midlands our guide is £1,750–£2,550 per m² including VAT, so about £31,500–£46,000 for 3 m × 6 m of new first-floor space (18 m²). Essential and Premium specs move that by roughly 8% down or 20% up.

Can I add an en-suite above the garage?

Yes, and it is a common choice for a main bedroom. The en-suite needs an extract fan under Part F, a route for the soil pipe down to the drains and enough fall for the waste, which can be harder over a garage. We plan the pipe route through the garage or an outside wall early.

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.

Will I need planning permission in the West Midlands?

West Midlands is in England. Planning permission is needed: in England, permitted development only allows single-storey extensions to the side.

Neighbouring areas

All extension services in the West Midlands · About extensions over a garage