Two-storey extensions for detached houses in Kilmarnock

Useful details for planning a two-storey extension for a detached house in Kilmarnock.

Postcode districts: KA1, KA2, KA3, KA4, KA16 and KA17
County / area: Ayrshire, Scotland
Price region: Scotland
Guide price: £81,000–£108,500 (£1,930–£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: Stewarton (4.8 miles), Irvine (6.2 miles), Troon (8.1 miles)
First visit: Free, no obligation

About a two-storey extension for a detached house

This service suits you if you own a detached house and want a substantial amount of extra space, whether a side extension over a drive, a rear extension into the garden or a wraparound. You get a survey of the whole plot, options that compare layouts and costs, the approvals your nation needs, structural design and the build, carried out by vetted teams working under S&K.

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

Our guide for Scotland is £1,930–£2,580 per m² including VAT. On a project with a 3 m × 7 m footprint on two floors (42 m² of new floor space), that puts a two-storey extension for a detached house in Kilmarnock at roughly £81,000–£108,500. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.

Spec	Per m²	A 3 m × 7 m footprint on two floors (42 m² of new floor space)
Essential	£1,770–£2,380 per m²	£74,500–£100,000
Standard	£1,930–£2,580 per m²	£81,000–£108,500
Premium	£2,310–£3,100 per m²	£97,000–£130,500

Planning and building standards in Kilmarnock

In Scotland, a detached house on a large plot may be able to use Class 1B permitted development if no part of the two-storey extension is within 10 m of any boundary, it is no higher than the house and is not in a conservation area. Otherwise a householder application costs £371. A building warrant is needed either way.

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

Larger spans and steelwork

Bigger extensions often mean wider openings and longer spans, which need more steel and sometimes a steel frame. The engineer designs these early, because the size of the steel affects ceiling heights, floor depths and the cost.

Keeping it subordinate

Large detached houses can take a large extension, but councils still expect it to look secondary to the main house. A lower ridge, a modest set-back at the front and matching materials keep the proportions right, even on a wide plot.

How we'd run your project

Visit and first ideas
One of our team visits your house in Kilmarnock, 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.
Structure and building standards
A structural engineer sizes the foundations and steels, and we get a building warrant before work starts.
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 extensions for detached houses 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.

How much does a two-storey extension for a detached house cost in Kilmarnock?

Our guide for Scotland, which covers Kilmarnock, is £1,930–£2,580 per m² including VAT. A typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £81,000–£108,500. 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 two-storey extension for a detached house in Kilmarnock?

Kilmarnock 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.

Is a detached house extension a better investment than moving?

It often costs less than the gap between your house and a larger one nearby, once property tax, legal fees and removal costs are counted, but that depends on your area. Extending also has limits: every street has a ceiling price. We give you build costs so you can compare them with local asking prices.

Can I extend a detached house on both sides?

Sometimes. With planning permission, a council may accept extensions on both sides if the house stays well proportioned and keeps gaps to the boundaries. It is more common to extend on one side and the rear, or with a wraparound. We look at the plot as a whole before suggesting more than one extension.

Nearby

We also cover places near Kilmarnock, including:

Other extensions in Kilmarnock

All two-storey extension services in Kilmarnock · Two-storey extensions for detached houses across Ayrshire

Tell us about your house in Kilmarnock and we'll call you back to arrange a free, no-obligation visit.