Ardrossan · Ayrshire

Part single, part two-storey extensions in Ardrossan

Want to stay in Ardrossan but need more space? A part single, part two-storey extension adds floor area on two levels without giving up much garden. Here's what's involved.

Before you start in Ardrossan, here's what applies.

Postcode districts
KA22 and KA23
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
Saltcoats (1.3 miles), Stevenston (2.2 miles), Kilwinning (3.9 miles)
Distance to Kilmarnock
about 12.4 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.

Around Ardrossan we also work in Saltcoats, Stevenston and Kilwinning, and across the rest of Ayrshire. Postcode districts in and near Ardrossan: KA22 and KA23.

What it costs in Ardrossan

Our guide for Scotland is £1,880–£2,580 per m² including VAT. On a project with a 6 m × 4 m ground floor and a first floor over half of it (36 m² in total), that puts a part single, part two-storey extension in Ardrossan at roughly £67,500–£93,000. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

SpecPer m²A 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 Ardrossan

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 Ardrossan 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.

Structure at the step

The first-floor wall above often sits over the new open-plan space, so it needs a steel beam or frame to carry it. Loads come down at different points than in a full two-storey design, and the engineer sizes the foundations to suit each part.

How we'd run your project

  1. Understand the brief

    At your home in Ardrossan we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.

  2. Drawings and permission

    Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Ardrossan.

  3. Detail and price

    Construction drawings, engineer's calculations and building warrant approval, then a written fixed price for the build.

  4. 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 Ardrossan

Who handles building standards for a project in Ardrossan?

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 Ardrossan?

Our guide for Scotland, which covers Ardrossan, 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.

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

Ardrossan 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.

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

The same service in neighbouring towns:

Other extensions in Ardrossan

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

The quickest next step is a visit. We'll look at your house in Ardrossan and give you an honest view of the options.

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