Kilwinning single-storey extensions, designed and built
Our design and build teams take on single-storey extensions in Kilwinning, from the first measured survey through planning and building control to the finished room.
- Guide price in KilwinningFrom £20,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Build time10–16 weeks on site
- Postcode districtsKA13
Planning rules that apply in Kilwinning
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.
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.
How much does a single-storey extension cost in Kilwinning?
Labour and material costs vary across the UK, so for Kilwinning we use our Scotland factor (×0.98). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Kilwinning: £1,720 to £3,330 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £20,500 – £24,500 | £24,000 – £31,000 | £30,500 – £40,000 |
| 4 m × 5 m 20 m² | £34,000 – £40,500 | £40,000 – £51,000 | £50,500 – £67,000 |
| 5 m × 6 m 30 m² | £51,000 – £60,500 | £60,000 – £76,500 | £76,000 – £100,000 |
For a figure based on your own dimensions, use our guide-price tool.
What is included
- Planning route checked and the right approval obtained
- Flat or pitched roof, rooflights or lantern
- Doors, windows, insulation, plastering and first fix to finish
- Building regulations drawings and structural calculations
- Walls, steel beams and the new opening into the house
- Foundations, drainage and groundworks
Depth is the big decision. Every extra metre adds floor area but also takes garden and can push you out of permitted development. We draw the room at two or three depths so you can see the trade-off in space, light and cost before anything is fixed.
Covering Kilwinning
Our survey diary covers Kilwinning, including KA13. We also work in nearby Saltcoats (3 miles), Irvine (3 miles), Troon (8 miles), Kilmarnock (9 miles).
Johnstone, in Renfrewshire and Inverclyde, is roughly 14 miles from Kilwinning and also on our list. 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.
Our process, step by step
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about single-storey extensions
Do I need building regulations approval in Kilwinning?
Yes. Almost every extension needs it, whatever the planning route. In Scotland that means a building warrant before work starts.
How long does a single-storey extension take to build in Kilwinning?
On site, typically 10 to 16 weeks once approvals are in place. Before that, allow 4–12 weeks design and approvals.
Who do I contract with for a single-storey extension in Kilwinning?
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 much does a single-storey extension cost per square metre?
Our guide range is about £1,720 to £3,330 per m² including VAT, depending on specification. A standard-spec 4 m × 5 m room usually lands at £40,000 to £51,000 in Kilwinning, plus design and council fees.
Flat roof or pitched roof?
Flat roofs give more headroom inside and suit lanterns and rooflights; pitched roofs can blend better with older houses. Both meet building regulations when built properly. See our flat roof and pitched roof pages for the details.
Book a free site visit in Kilwinning
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.