A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
We take on a double-storey extension throughout Stranraer and the surrounding DG9 postcodes, as well as in Bangor, County Down, Larne and Carrickfergus. The guide range for this work in Scotland is £58,000–£115,000 including VAT; where your project falls depends on its size, the materials you pick and how easy the site is to reach. A free survey turns that range into a fixed figure.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- DG9
- Planning rules
- Scotland
- Local area
- Dumfries and Galloway
- Survey
- Free, with a written quote
Double-storey extensions prices in Stranraer
What should you budget for a double-storey extension in Stranraer? Use the figures below as a starting point. Prices in Scotland sit about 4% below the national guide, so the range here is £58,000–£115,000 including VAT. Your fixed price comes in writing once we've surveyed the property, at no charge.
| Type of job | What it usually involves | Guide in Stranraer |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,500–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £58,000–£115,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £96,000–£173,000 |
What moves the price up or down:
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
Scope of the work
- Groundworks, foundations and below-ground drainage
- First-floor joists, stud walls and new openings upstairs
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Building in Stranraer
Dumfries is known for red sandstone buildings, and older towns across the region, such as Kirkcudbright and Castle Douglas, have Georgian and Victorian streets. Rural homes are often harled whinstone or sandstone farmhouses and cottages under slate roofs, with post-war and modern housing on the edges of towns such as Stranraer and Annan.
Stone and harled homes commonly need lime-based repairs, re-harling and roof slating work. Town houses suit extensions and loft conversions, and rural properties often take porches, driveways and fencing.
Knowing the typical building types in Dumfries and Galloway helps, but a survey of your own home in Stranraer is what decides the right approach to a double-storey extension.
Permissions for a double-storey extension in Stranraer
Which rules apply depends on where you live. For Stranraer, the answer is Scotland, and the points below reflect that; we verify them with the council before quoting.
In Scotland, extensions of more than one storey are only permitted development in narrow cases (Class 1B, well away from the boundary they face and outside conservation areas), so most need planning permission.
A building warrant is required before work starts. Scotland has no Party Wall Act; neighbour and title issues are handled under general law.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
The four stages
We look at the job
A free survey comes first. It gives us what we need to price a double-storey extension properly, including dimensions, existing materials and access for deliveries, and gives you the chance to ask anything you like.
Price and scope agreed
The quote arrives in writing, not over the phone. It covers the full scope, the finishes you've chosen, any exclusions and the payment schedule, with a fixed price tied to that specification.
Booking the work
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Stranraer property.
Build and hand over
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
How we work
Double-storey extensions in Stranraer: questions
How much will a double-storey extension cost in Stranraer?
As a guide, expect to pay £58,000–£115,000 including VAT for a double-storey extension in Stranraer. That range is adjusted for Scotland, which runs about 4% below the national guide. Where your project lands depends on size, materials, access and the condition of what is already there. We confirm a fixed price in writing after a free survey of your home.
Will the extension affect my neighbours?
A double-storey extension can affect neighbours' light, outlook and privacy, which is why planning departments look closely at height, depth and window positions. Side windows facing neighbours often need obscure glass. Work near a shared wall may also need party wall notices; the Party Wall etc. Act 1996 applies in England and Wales only. We talk through these points early so the design is realistic.
Do you cover Bangor, County Down, Larne and Carrickfergus?
Yes. As well as Stranraer, we cover Bangor, County Down, Larne and Carrickfergus and the rest of Dumfries and Galloway. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
Can the new upstairs room have its own bathroom?
A new upstairs room can usually have an en-suite, provided waste pipes can reach the soil stack or a new one can be installed. Running the waste pipe to the right falls is the main design question, and a pumped system is an option where gravity will not work. We plan bathroom positions at the design stage so pipes, ventilation and insulation are built in rather than added later.
How long does a double-storey extension take?
A double-storey extension typically takes 14–22 weeks on site, depending on size, roof design and weather. Foundations and ground-floor walls come first, then the first-floor joists, upper walls and roof. Once it is weathertight, electrics, plumbing, plastering and finishes follow. Allow extra time beforehand for drawings, calculations and approvals. We give you a stage-by-stage programme with your quote.
Near Stranraer
Addresses in DG9 are all covered for Stranraer, along with Bangor, County Down, Larne and Carrickfergus close by. Give us your postcode when you get in touch and we will confirm the details.

