Two-storey rear extensions in Stevenston

Stevenston: the key facts for this kind of project.

Postcode districts: KA20
County / area: Ayrshire, 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: Saltcoats (1.3 miles), Kilwinning (2.1 miles), Ardrossan (2.2 miles)
Distance to Kilmarnock: about 10.2 miles
First visit: Free, no obligation

About a two-storey rear extension

A two-storey rear extension is a new two-floor addition built onto the back of your house, usually giving a larger kitchen or living space on the ground floor and one or two bedrooms or a bathroom above. Because both floors share one set of foundations and one roof, it adds a lot of floor space for the garden it uses. In some cases it can be built under permitted development, depending on where you live.

We cover postcode district KA20 in and around Stevenston, along with neighbouring Saltcoats, Kilwinning and Ardrossan.

What it costs in Stevenston

A guide price for Stevenston: around £52,500–£71,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). That works out at £1,880–£2,540 per m² of new floor space, including VAT at 20%. Professional fees for drawings and the structural engineer are listed separately on our prices page.

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 Stevenston

In Scotland, a two-storey rear extension is only permitted development under Class 1B if no part of it is within 10 m of any boundary, it is no higher than the house and the house is not in a conservation area. Most gardens cannot meet the 10 m test, so expect a householder application (£371, decided within two months) and a building warrant before 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 Stevenston homes

Foundations and drains

Foundations for two storeys carry more load than a single storey and may need to go deeper near trees or on clay. Rear extensions often sit near drains, so we check sewer records early, as building over or near a public sewer may need the water company's agreement.

Depth and neighbours' light

Councils check that a two-storey rear extension does not take too much light or outlook from neighbouring windows, and many use a 45-degree line drawn from the nearest habitable window. We test this at sketch stage, so the depth you are shown is one that can realistically be approved.

How we'd run your project

Visit and first ideas
One of our team visits your house in Stevenston, checks the walls, roof and drains, and sketches out options with you.
Drawings, then consent
We draw the scheme, check it against the rules in Scotland, and take it through the right consent with the council.
Fixed price in writing
With approved drawings and calculations, we give you a fixed build price and a programme you can plan around.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

Questions about two-storey rear extensions in Stevenston

Do I need planning permission for a two-storey rear extension in Stevenston?

Stevenston 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 Stevenston?

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 two-storey rear extension cost in Stevenston?

Our guide for Scotland, which covers Stevenston, 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.

How long does a two-storey rear 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.

Will a two-storey rear extension block my neighbour's light?

It can if it is too deep or too close to the boundary, which is why councils look closely at its effect on neighbouring windows and gardens. We test the design against light and outlook early, keep the first floor shorter or set in where needed, and use a hipped roof to reduce bulk on the boundary side.

Nearby

Other towns near Stevenston:

Other extensions in Stevenston

All two-storey extension services in Stevenston · Two-storey rear extensions across Ayrshire

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