Annexe extensions across Kilmarnock
From the first sketch to final sign-off, we plan and build annexe extensions in Kilmarnock and the surrounding Ayrshire area.
- Guide price in KilmarnockFrom £53,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Build time16–24 weeks on site
- Postcode districtsKA1, KA2, KA3

Planning and approvals in Kilmarnock
In Scotland, householder permitted development rules (Class 1A for single-storey ground-floor extensions and Class 1B for extensions of more than one storey) allow some smaller extensions without a planning application, within limits on depth, height and distance from the boundary. Conservation areas and listed buildings are more restricted. Separately, almost every extension needs a building warrant from the council before work starts.
Homes in conservation areas, national scenic areas and listed buildings have tighter rules, so we always check the property's status and planning history before design starts.
Building close to a public sewer needs the agreement of Scottish Water, which we check during design.
Scotland has no Party Wall Act. Where work affects a shared wall or a neighbour's land, we agree access, protection and making good with your neighbour in writing before work starts.
Applications are decided by your council as planning authority.
Guide prices for Kilmarnock
These guide figures apply our Scotland adjustment (×0.98) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Kilmarnock: £1,960 to £3,720 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £53,500 – £67,500 | £58,500 – £73,500 | £73,500 – £93,500 |
| One-bedroom annexe 35 m² | £68,500 – £86,000 | £82,000 – £103,000 | £102,500 – £130,500 |
| Larger annexe 45 m² | £88,000 – £110,500 | £105,500 – £132,500 | £132,000 – £168,000 |
Try the guide-price tool to see a range for your own size and finish.
Included in a typical project
- Fire separation and alarms to building regulations
- Planning application describing ancillary use
- Design for accessibility: level thresholds, wider doors, walk-in shower
- Separate or shared heating and hot water
- Kitchenette, shower room and bedroom finish
Covering Kilmarnock
We cover Kilmarnock and the postcode districts KA1, KA2, KA3. The same team covers Irvine (6 miles), Troon (7 miles), Kilwinning (9 miles), Saltcoats (11 miles), all within easy reach.
For homes towards Renfrewshire and Inverclyde, Newton Mearns is around 13 miles away. Scotland's housing includes sandstone villas, terraces and tenements in the cities and plenty of post-war and modern houses and bungalows elsewhere. A building warrant is needed before work starts.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Your questions about an annexe extension in Kilmarnock
Who do I contract with for an annexe extension in Kilmarnock?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
How long does an annexe extension take to build in Kilmarnock?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Kilmarnock, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
How much does an annexe extension cost?
Our guide range is about £1,960 to £3,720 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £82,000 to £103,000 at standard spec in Kilmarnock.
Does an annexe extension need planning permission?
Usually yes, because of its size and the way it will be used. Councils check that it stays ancillary to the main house, so the application must describe the use clearly.
Book a free site visit in Kilmarnock
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.