Ayrshire
Single-storey rear extensions in Ayrshire
Ground-floor space across the back of the house, usually for a kitchen, dining or family room. Rear extensions in Ayrshire: we cover 9 towns including Kilmarnock, Ayr and Irvine, with design, approvals and the build under one contract.

A single-storey rear extension in Kilmarnock is mostly built from the garden side, so the house stays usable for most of the job. Post-war semis and terraces are common around Ayrshire, and many have room for a single-storey rear extension within Class 1A limits.
How much does a single-storey rear extension cost in Ayrshire?
For Ayrshire we work from the Scotland rate: £1,800–£2,940 per square metre of new floor, including VAT, standard specification. Prices in Scotland sit a little below our West Midlands baseline; building warrant fees and drawings are budgeted separately.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,500–£35,500 |
| 4 m wide × 5 m deep (20 m²) | £36,000–£59,000 |
| 4 m wide × 6 m deep (24 m²) | £43,500–£70,500 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
Do you need planning permission in Ayrshire?
In Scotland a single-storey rear extension can be permitted development under Class 1A: eaves no higher than 3 metres and an overall height of 4 metres, and where any part is within 1 metre of a boundary it can project no more than 3 metres on a terraced house or 4 metres on other houses. The rights do not apply in conservation areas, and a building warrant is still needed before work starts.
Scotland has no larger-extension prior approval route; extensions beyond permitted development need a planning application.
Classes 1A and 1B do not apply in conservation areas, and listed buildings need listed building consent.
Where in Ayrshire do we work?
FAQ
Questions people ask
Is a flat roof or a pitched roof better?
A warm flat roof keeps the extension low under first-floor windows and suits a roof lantern; a pitched or lean-to roof gives a vaulted ceiling. Both last for decades when built properly.
Can I stay in the house during the build?
Usually yes. The noisiest, dustiest stage, removing the back wall, is kept to the final weeks and screened off. Most families set up a temporary kitchen elsewhere in the house.
Will the extension make the room behind it dark?
Not if it is designed well. Rooflights or a lantern over the old back room, and a wide opening into it, keep daylight reaching the middle of the house.
Do you cover all of Ayrshire?
We cover 9 towns and districts in Ayrshire, including Kilmarnock, Ayr and Irvine.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.