Two-storey extensions for semi-detached houses in Isle of Islay
A two-storey extension for a semi-detached house is one of the most space-efficient ways to add bedrooms and living space to a house in Isle of Islay, because the new floors share one set of foundations and one roof.
We take on projects in Isle of Islay by arrangement. Site visits here aren't free as standard, and we'll agree travel costs with you in writing first.
What we'd confirm first for a project in Isle of Islay.
- Postcode districts
- PA43, PA44, PA45, PA46, PA48 and PA49
- 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
- Isle of Mull (49.1 miles), Campbeltown (35 miles), Lochgilphead (35.8 miles)
- Distance to Helensburgh
- about 60.5 miles
- First visit
- By arrangement
About a two-storey extension for a semi-detached house
This service suits you if you own a semi-detached house and want to add bedrooms and living space without moving. On a semi, the main questions are which side to build on and how to treat the attached neighbour. You get a survey, design options, the approvals your nation needs and the build, carried out by vetted teams working under S&K.
We cover Isle of Islay (PA43, PA44, PA45, PA46, PA48 and PA49) and the places around it, including Isle of Mull (49.1 miles), Campbeltown (35.0 miles) and Lochgilphead.
What it costs in Isle of Islay
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 a two-storey extension for a semi-detached house in Isle of Islay at roughly £52,500–£71,000. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.
| 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 Isle of Islay
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 Isle of Islay homes
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.
The attached neighbour's light
A two-storey rear extension next to the party wall can take light from the neighbour's rear windows. Councils often use a 45-degree test, so the first floor may need to be shorter than the ground floor or set in from the shared boundary.
How we'd run your project
Visit by arrangement
We agree a visit to your home in Isle of Islay and any travel costs with you in writing first, then look at the structure, access and boundaries.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.
Questions about two-storey extensions for semi-detached houses in Isle of Islay
Which postcodes do you cover around Isle of Islay?
We cover Isle of Islay (PA43, PA44, PA45, PA46, PA48 and PA49) and nearby places including Isle of Mull, Campbeltown and Lochgilphead, plus the rest of Argyll and Bute. Visits and projects in Isle of Islay are by arrangement, with travel costs agreed in writing first.
Who handles building standards for a project in Isle of Islay?
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.
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.
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.
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
Close to Isle of Islay? We work across the area, including:
Other extensions in Isle of Islay
- 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 Isle of Islay · Two-storey extensions for semi-detached houses across Argyll and Bute
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Isle of Islay.