Part single, part two-storey extensions in Largs

The basics for Largs at a glance.

Postcode districts: KA28, KA29, KA30 and PA17
County / area: Ayrshire, 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: Kilbirnie (7.5 miles), Rothesay (8 miles), Dalry (8.1 miles)
Distance to Kilmarnock: about 19.2 miles
First visit: Free, no obligation

About a part single, part two-storey extension

A part single, part two-storey extension is an extension where the ground floor is wider or deeper than the floor above, so only part of it rises to two storeys. It usually gives a large kitchen or living area with roof lights below and one bedroom or bathroom above. It is often a good way to add space while limiting the effect on neighbours.

Largs sits about 19.2 miles from Kilmarnock. Closer to home, Kilbirnie is 7.5 miles away and Rothesay 8.0 miles.

What it costs in Largs

In Scotland, which includes Largs, we'd expect a part single, part two-storey extension to cost around £67,500–£93,000 for a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total), or £1,880–£2,580 per m² including VAT. Design fees, structural calculations and approval fees are separate and listed on our prices page.

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 Largs

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 Largs 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

Free site visit
We visit your home in Largs, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
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.
Finish and certify
Second fix, plastering and making good, then the council's final building standards inspection and the completion paperwork.

Questions about part single, part two-storey extensions in Largs

Do I need planning permission for a part single, part two-storey extension in Largs?

Largs 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.

Who handles building standards for a project in Largs?

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 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.

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.

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.

Nearby

Close to Largs? We work across the area, including:

Other extensions in Largs

All two-storey extension services in Largs · Part single, part two-storey extensions across Ayrshire

Book a free site visit in Largs and we'll tell you what's possible, what approvals you need and what the design stage would cost.