Extra bedroom and en-suite extensions in Castle Douglas
Homes in Castle Douglas with a bit of space to the side or rear can often take an extra bedroom and en-suite extension. We'll tell you honestly whether yours can, and what approvals it needs.
What we'd confirm first for a project in Castle Douglas.
- Postcode districts
- DG7
- County / area
- Dumfries and Galloway, Scotland
- Price region
- Scotland
- Guide price
- £52,500–£71,000 (£1,880–£2,540 per m²), plus £5,500–£11,000 for the en-suite
- 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
- Dalbeattie (4.2 miles), Kirkcudbright (8.6 miles), Dumfries (15.4 miles)
- Distance to Dumfries
- about 15.4 miles
- First visit
- Free, no obligation
About an extra bedroom and en-suite extension
An extra bedroom and en-suite extension is a two-storey extension planned around a new double bedroom with its own shower room on the first floor, with a ground-floor room below. It is one of the most effective ways to add space for a growing family. Nationwide's 2025 research linked adding a double bedroom and bathroom to a three-bed, one-bathroom house with value gains of up to 24%.
We cover Castle Douglas (DG7) and the places around it, including Dalbeattie (4.2 miles), Kirkcudbright (8.6 miles) and Dumfries.
What it costs in Castle Douglas
Our guide for Scotland is £1,880–£2,540 per m² including VAT. On a project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that puts an extra bedroom and en-suite extension in Castle Douglas at roughly £52,500–£71,000 (plus £5,500–£11,000 for the en-suite). Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,730–£2,330 per m² | £48,500–£65,500 |
| Standard | £1,880–£2,540 per m² | £52,500–£71,000 |
| Premium | £2,260–£3,050 per m² | £63,000–£85,500 |
Planning and building standards in Castle Douglas
In Scotland, an extra bedroom on a new first floor makes the extension more than one storey, so Class 1B applies, needing at least 10 m to every boundary. Most plots need a householder application, which costs £371 and is decided within two months. The building warrant then covers the escape window, ventilation and drainage.
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 Castle Douglas homes
Escape window and fire safety
A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and high, and the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs. We design the windows to meet this.
Sound and privacy
Bedrooms above a kitchen or family room benefit from an insulated floor to reduce noise. Side-facing upstairs windows usually have to be obscure-glazed, so we place the main bedroom window to the rear and the en-suite window to the side where possible.
How we'd run your project
Free site visit
We visit your home in Castle Douglas, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Castle Douglas.
Engineer it
Foundations sized for two floors, steels for any openings, and a building warrant, all before anyone starts on site.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.
Questions about extra bedroom and en-suite extensions in Castle Douglas
Who handles building standards for a project in Castle Douglas?
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 extra bedroom and en-suite extension in Castle Douglas?
Castle Douglas 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 Castle Douglas?
We cover Castle Douglas (DG7) and nearby places including Dalbeattie, Kirkcudbright and Dumfries, plus the rest of Dumfries and Galloway. The first site visit is free.
What goes on the ground floor below a new bedroom?
Whatever suits you: a bigger kitchen, a family room, a study, a utility or a downstairs shower room. The ground floor usually costs about the same whatever it is used for, apart from kitchen units and bathroom fittings, which are priced separately.
Does an extra bedroom add value to my house?
It usually does, though not always by the full cost. Nationwide's 2025 research found that adding a double bedroom to a two-bed house was linked to about 13% higher value, and a double bedroom and bathroom on a three-bed, one-bathroom house up to 24%. Local ceiling prices still apply.
Nearby
The same service in neighbouring towns:
Other extensions in Castle Douglas
All two-storey extension services in Castle Douglas · Extra bedroom and en-suite extensions across Dumfries and Galloway
Want a figure first? Try our guide price tool, then book a free visit to firm it up.