Extensions over a garage in Washwood Heath

Quick reference for homeowners in Washwood Heath.

Postcode districts: B8, B9, B23 and B24
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 (1.8 miles), Aston (2.4 miles), Birmingham (3.4 miles)
Distance to Birmingham: about 3.4 miles
First visit: Free, no obligation

About an extension over a garage

An extension over a garage suits you if you have an attached single garage beside the house and need an extra bedroom or a larger main bedroom with an en-suite. You get an inspection of the garage structure, a design that matches the house, the approvals your nation needs, structural design, building regulations approval and the build, carried out by vetted teams working under S&K.

We cover Washwood Heath (B8, B9, B23 and B24) and the places around it, including Castle Vale (1.8 miles), Aston (2.4 miles) and Birmingham.

What it costs in Washwood Heath

Most of the cost of an extension over a garage is set by its size and specification. For Washwood Heath and the rest of 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). Keep a contingency of around 10% for things nobody can see until the ground is opened up.

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 Washwood Heath

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 Washwood Heath homes

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.

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

Visit and first ideas
One of our team visits your house in Washwood Heath, checks the walls, roof and drains, and sketches out options with you.
Get it approved
Once you're happy with the design we submit it to the council for Washwood Heath 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.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the building control completion certificate at the end.

Questions about extensions over a garage in Washwood Heath

Which postcodes do you cover around Washwood Heath?

We cover Washwood Heath (B8, B9, B23 and B24) and nearby places including Castle Vale, Aston and Birmingham, plus the rest of the West Midlands. The first site visit is free.

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 Washwood Heath?

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.

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

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Other extensions in Washwood Heath

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