Two-storey extensions for semi-detached houses in Kirkwall
If you live in Kirkwall and need more room without moving, a two-storey extension for a semi-detached house is worth a serious look. We handle the drawings, approvals, structure and build.
Kirkwall 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.
Useful details for planning a two-storey extension for a semi-detached house in Kirkwall.
- Postcode districts
- KW15 and KW17
- County / area
- The Highlands, Moray and Islands, 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
- Thurso (33.9 miles), Wick (38 miles), Lossiemouth (88.1 miles)
- Distance to Inverness
- about 113.8 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.
We cover postcode districts KW15 and KW17 in and around Kirkwall, along with neighbouring Thurso, Wick and Lossiemouth.
What it costs in Kirkwall
In Scotland, which includes Kirkwall, we'd expect a two-storey extension for a semi-detached house to cost around £52,500–£71,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), or £1,880–£2,540 per m² including VAT. 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 Kirkwall
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 Kirkwall 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 Kirkwall and any travel costs with you in writing first, then look at the structure, access and boundaries.
Drawings, then consent
We draw the scheme, check it against the rules in Scotland, and take it through the right consent with the council.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the completion certificate at the end.
Questions about two-storey extensions for semi-detached houses in Kirkwall
Which postcodes do you cover around Kirkwall?
We cover Kirkwall (KW15 and KW17) and nearby places including Thurso, Wick and Lossiemouth, plus the rest of the Highlands, Moray and Islands. Visits and projects in Kirkwall are by arrangement, with travel costs agreed in writing first.
Do I need planning permission for a two-storey extension for a semi-detached house in Kirkwall?
Kirkwall 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 much does a two-storey extension for a semi-detached house cost in Kirkwall?
Our guide for Scotland, which covers Kirkwall, is £1,880–£2,540 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £52,500–£71,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
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.
What if my neighbour has already extended?
That often helps. An existing extension next door can reduce the effect of yours on their light, and may show what the council accepts on your street. It can also mean building alongside their wall, so we check its position, foundations and any windows facing your plot at the survey.
Nearby
Nearby towns we cover for two-storey extensions for semi-detached houses:
Other extensions in Kirkwall
- 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 Kirkwall · Two-storey extensions for semi-detached houses across the Highlands, Moray and Islands
The quickest next step is a visit. We'll look at your house in Kirkwall and give you an honest view of the options.