Two-storey extensions for semi-detached houses in Campbeltown
Our two-storey extensions for semi-detached houses service in Campbeltown covers everything: measured survey, design, planning or permitted development checks, structural design, building control and the build itself.
Campbeltown is outside our usual mainland visit area, so visits and projects here are by arrangement. We'll agree any travel costs with you before anything is booked.
The basics for Campbeltown at a glance.
- Postcode districts
- PA28
- County / area
- Argyll and Bute, Scotland
- Price region
- Scotland
- Guide price
- £52,500–£71,000 (£1,880–£2,540 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
- Girvan (32.2 miles), Ardrossan (34.9 miles), Saltcoats (35.3 miles)
- Distance to Helensburgh
- about 52.8 miles
- First visit
- By arrangement
About a two-storey extension for a semi-detached house
A two-storey extension for a semi-detached house is a two-floor addition to the rear, the open side, or both, designed around the attached neighbour on one side. The rear is often the simplest option and can sometimes be permitted development, while a side extension uses the gap on the detached side. Both need care with the shared party wall and the neighbour's light.
Campbeltown sits about 52.8 miles from Helensburgh. Closer to home, Girvan is 32.2 miles away and Ardrossan 34.9 miles.
What it costs in Campbeltown
Most of the cost of a two-storey extension for a semi-detached house is set by its size and specification. For Campbeltown and the rest of Scotland, our guide is £1,880–£2,540 per m² including VAT, so about £52,500–£71,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). 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 | 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 Campbeltown
In Scotland, Class 1B permitted development needs a two-storey extension to be at least 10 m from every boundary, which a semi-detached house cannot meet on the attached side. In practice a two-storey extension to a semi needs a householder application, which costs £371 and is decided within two months, followed by 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 Campbeltown homes
Keeping the pair balanced
Semis are designed as matching pairs, and a side extension changes that balance. Setting the side extension back from the front wall and keeping its ridge lower helps the pair still read as a pair, which councils' design guides commonly ask for.
Rear, side or both
On a semi, a rear extension sits against the attached neighbour, while a side extension faces the detached neighbour and the street. We compare the space, cost and approval route for each, and for a wraparound, before you commit to one design.
How we'd run your project
Visit by arrangement
We agree a visit to your home in Campbeltown and any travel costs with you in writing first, then look at the structure, access and boundaries.
Design and approvals
We draw the extension and check it against the rules for Scotland, then apply for planning permission or a certificate of lawfulness, whichever fits.
Structure and building standards
A structural engineer sizes the foundations and steels, and we get a building warrant before work starts.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.
Questions about two-storey extensions for semi-detached houses in Campbeltown
Do I need planning permission for a two-storey extension for a semi-detached house in Campbeltown?
Campbeltown 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 a two-storey extension for a semi-detached house 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.
Which postcodes do you cover around Campbeltown?
We cover Campbeltown (PA28) and nearby places including Girvan, Ardrossan and Saltcoats, plus the rest of Argyll and Bute. Visits and projects in Campbeltown are by arrangement, with travel costs agreed in writing first.
Does a two-storey extension add value to a semi-detached house?
It usually adds value, but the gain is never certain. Nationwide's 2025 research found that 10% more floor area was linked to about 5% higher value, and that adding a double bedroom and bathroom to a three-bed, one-bathroom house could add up to 24%. Every street has a ceiling price, so check local sales first.
Will a side extension make my semi look like a terrace?
It can if it fills the whole gap to the boundary at first floor and the neighbour does the same. Many councils ask for a first-floor gap to the side boundary or a set-back for this reason. We design the extension to keep the semi reading as one of a pair.
Nearby
We also cover places near Campbeltown, including:
Other extensions in Campbeltown
- Rear
- Side
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Campbeltown · Two-storey extensions for semi-detached houses across Argyll and Bute
Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.