Extensions over a garage in Dumfries

What we'd confirm first for a project in Dumfries.

Postcode districts: DG1 and DG2
County / area: Dumfries and Galloway, Scotland
Price region: Scotland
Guide price: £29,500–£43,000 (£1,640–£2,400 per m²)
Approval route: Planning permission is usually needed: Class 1B permitted development only applies if every part of the extension is at least 10 m from all boundaries. A building warrant is needed before work starts.
Nearest towns: Locharbriggs (2.6 miles), Lockerbie (10.7 miles), Dalbeattie (12.6 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 Dumfries (DG1 and DG2) and the places around it, including Locharbriggs (2.6 miles), Lockerbie (10.7 miles) and Dalbeattie.

What it costs in Dumfries

Guide prices for extensions over a garage in Scotland are around £1,640–£2,400 per m² of new floor space, including VAT. For a typical project with 3 m × 6 m of new first-floor space (18 m²), that's roughly £29,500–£43,000. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

Spec	Per m²	3 m × 6 m of new first-floor space (18 m²)
Essential	£1,510–£2,210 per m²	£27,000–£39,500
Standard	£1,640–£2,400 per m²	£29,500–£43,000
Premium	£1,970–£2,880 per m²	£35,500–£52,000

Planning and building standards in Dumfries

In Scotland, a room over a garage makes the extension more than one storey, so Class 1B applies, which needs at least 10 m to every boundary for permitted development. Attached garages are rarely that far from the boundary, so expect a householder application (£371, decided within two months) and a building warrant.

Approval in Scotland: Householder planning application: £371. Councils have two months to decide a local planning application.

Building standards: A building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks.

Design points for Dumfries homes

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.

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 standards. 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 Dumfries 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 Dumfries.
Detail and price
Construction drawings, engineer's calculations and building warrant approval, 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.

Questions about extensions over a garage in Dumfries

Who handles building standards for a project in Dumfries?

We handle it as part of the project. What's needed in Scotland: a building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

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

Dumfries is in Scotland. Planning permission is usually needed: Class 1B permitted development only applies if every part of the extension is at least 10 m from all boundaries. A building warrant is needed before work starts.

How long does an extension over a garage take?

Allow 4 to 8 weeks for survey and design, then the approval period (councils have two months to decide a local planning application), 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.

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 Dumfries? We work across the area, including:

Other extensions in Dumfries

All two-storey extension services in Dumfries · Extensions over a garage across Dumfries and Galloway

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