Two-storey rear extensions in Kilmarnock
A two-storey rear extension is one of the most space-efficient ways to add bedrooms and living space to a house in Kilmarnock, because the new floors share one set of foundations and one roof.
Before you start in Kilmarnock, here's what applies.
- Postcode districts
- KA1, KA2, KA3, KA4, KA16 and KA17
- 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
- Stewarton (4.8 miles), Irvine (6.2 miles), Troon (8.1 miles)
- First visit
- Free, no obligation
About a two-storey rear extension
A two-storey rear extension suits you if you need more room on both floors and have a reasonably deep garden. You get one team for the whole job: a measured survey, the design, a check on whether permitted development applies, planning drawings where they are needed, structural design, a building warrant and the build itself, carried out by vetted teams working under S&K. Every project starts with a free site visit.
We cover postcode districts KA1, KA2, KA3, KA4, KA16 and KA17 in and around Kilmarnock, along with neighbouring Stewarton, Irvine and Troon.
What it costs in Kilmarnock
Using our Scotland rates, a two-storey rear extension with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £52,500–£71,000, including VAT. Bigger or more glazed designs cost more per m². 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 Kilmarnock
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 Kilmarnock homes
Opening up the ground floor
Knocking through the old rear wall means steel beams to carry the first floor and roof above. The structural engineer sets the beam sizes, padstones and any posts, and we plan them early so the open-plan layout you want is the one that gets built.
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.
How we'd run your project
Measure and listen
A visit to Kilmarnock to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Drawings, then consent
We draw the scheme, check it against the rules in Scotland, and take it through the right consent with the council.
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 two-storey rear extensions in Kilmarnock
Which postcodes do you cover around Kilmarnock?
We cover Kilmarnock (KA1, KA2, KA3, KA4, KA16 and KA17) and nearby places including Stewarton, Irvine and Troon, plus the rest of Ayrshire. The first site visit is free.
Who handles building standards for a project in Kilmarnock?
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 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.
How much does a two-storey rear extension cost in Kilmarnock?
Our guide for Scotland, which covers Kilmarnock, 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.
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
Nearby towns we cover for two-storey rear extensions:
Other extensions in Kilmarnock
- Side
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Kilmarnock · Two-storey rear extensions across Ayrshire
Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.