Extensions over a garage in Gretna
For an extension over a garage in Gretna, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Dumfries and Galloway.
Useful details for planning an extension over a garage in Gretna.
- Postcode districts
- DG16
- 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
- Annan (7.6 miles), Lockerbie (14.6 miles), Locharbriggs (21.9 miles)
- Distance to Dumfries
- about 22.2 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 Gretna we also work in Annan, Lockerbie and Locharbriggs, and across the rest of Dumfries and Galloway. Postcode district in and near Gretna: DG16.
What it costs in Gretna
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. 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 | £1,510–£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 Gretna
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 Gretna homes
Checking the garage foundations
Garages are often built on shallow strip footings sized for a single-storey wall and a light roof. A trial hole shows their depth and condition, and the engineer decides whether they can carry two storeys or need underpinning or new foundations inside the garage.
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'd run your project
Measure and listen
A visit to Gretna to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Drawings, then consent
We draw the scheme, check it against the rules in Scotland, and take it through the right consent with the council.
Engineer it
Foundations sized for two floors, steels for any openings, and a building warrant, all before anyone starts on site.
Finish and certify
Second fix, plastering and making good, then the council's final building standards inspection and the completion paperwork.
Questions about extensions over a garage in Gretna
Who handles building standards for a project in Gretna?
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 Gretna?
Gretna 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.
Which postcodes do you cover around Gretna?
We cover Gretna (DG16) and nearby places including Annan, Lockerbie and Locharbriggs, plus the rest of Dumfries and Galloway. The first site visit is free.
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.
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.
Nearby
Close to Gretna? We work across the area, including:
Other extensions in Gretna
- Rear
- Side
- Wraparound
- Part two-storey
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Gretna · Extensions over a garage across Dumfries and Galloway
Book a free site visit in Gretna and we'll tell you what's possible, what approvals you need and what the design stage would cost.