Part single, part two-storey extensions in Rothesay
Adding a part single, part two-storey extension in Rothesay gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in Scotland.
Rothesay 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.
Rothesay: the key facts for this kind of project.
- Postcode districts
- PA20 and PA21
- County / area
- Argyll and Bute, Scotland
- Price region
- Scotland
- Guide price
- £67,500–£93,000 (£1,880–£2,580 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
- Largs (8 miles), Dunoon (9.3 miles), Gourock (12.6 miles)
- Distance to Helensburgh
- about 17.3 miles
- First visit
- By arrangement
About a part single, part two-storey extension
A part single, part two-storey extension suits you if you want a generous ground floor but only need one extra room upstairs, or if a full two-storey design would affect a neighbour too much. You get design options that test where the two-storey part works best, the approvals your nation needs, structural design, a building warrant and the build, carried out by vetted teams working under S&K.
Around Rothesay we also work in Largs, Dunoon and Gourock, and across the rest of Argyll and Bute. Postcode districts in and near Rothesay: PA20 and PA21.
What it costs in Rothesay
Most of the cost of a part single, part two-storey extension is set by its size and specification. For Rothesay and the rest of Scotland, our guide is £1,880–£2,580 per m² including VAT, so about £67,500–£93,000 for a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total). We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.
| Spec | Per m² | A 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) |
|---|---|---|
| Essential | £1,730–£2,380 per m² | £62,500–£85,500 |
| Standard | £1,880–£2,580 per m² | £67,500–£93,000 |
| Premium | £2,260–£3,100 per m² | £81,000–£111,500 |
Planning and building standards in Rothesay
In Scotland, because part of the extension is more than one storey, it is assessed under Class 1B, which needs at least 10 m to every boundary for permitted development. On most plots that is not possible, so the extension needs a householder application (£371, decided within two months). A building warrant is also needed before any work starts.
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 Rothesay homes
The roof junction
Where the single-storey roof meets the two-storey wall you need a sound weathering detail, usually a lead or similar flashing, and enough height for roof lights or a lantern. We set the roof falls and the upstairs window sill heights together so they do not clash.
Where to put the two-storey part
The two-storey section usually works best away from the closest neighbour, with the single-storey part on that boundary side. We test a few positions against neighbours' windows, the upstairs layout and the roof shape before choosing the one to take forward.
How we'd run your project
Visit by arrangement
We agree a visit to your home in Rothesay 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.
Detail and price
Construction drawings, engineer's calculations and building warrant approval, then a written fixed price for the build.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the completion certificate at the end.
Questions about part single, part two-storey extensions in Rothesay
How long does a part single, part two-storey extension 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.
Who handles building standards for a project in Rothesay?
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 much does a part single, part two-storey extension cost in Rothesay?
Our guide for Scotland, which covers Rothesay, is £1,880–£2,580 per m² including VAT. A typical project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total) comes to about £67,500–£93,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Which side should the two-storey part go on?
Usually the side furthest from the nearest neighbour's windows, so the single-storey part sits nearest them and keeps their light. Other factors are where the stairs land upstairs, which room needs the extra space and where drains run. We sketch options at the design stage and explain which is most likely to be approved.
Can the single-storey part be deeper than the two-storey part?
With planning permission, yes, and that is often the point of the design: the ground floor projects further into the garden while the first floor stays back from neighbours. Under permitted development, the depth limits for extensions of more than one storey can apply to the whole extension, so we confirm which route applies before drawings are finalised.
Nearby
Other towns near Rothesay:
Other extensions in Rothesay
- Rear
- Side
- Wraparound
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Rothesay · Part single, part two-storey extensions across Argyll and Bute
The quickest next step is a visit. We'll look at your house in Rothesay and give you an honest view of the options.