If you are weighing up a kitchen extension or an extra room in North Ayrshire, the first question is always the same: what is this actually going to cost? Here is an honest breakdown of the real figures, what pushes them up or down, and where homeowners around Kilwinning tend to get caught out.
As a rough guide for 2026, a single storey extension in Scotland tends to land somewhere between £2,000 and £3,000 per square metre for a standard finish, with most projects we see falling in the £30,000 to £75,000 range once everything is accounted for.
A modest 15 square metre rear extension might come in around £35,000 to £45,000, while a larger 30 square metre open plan kitchen and dining space with quality glazing can comfortably reach £60,000 or more. The figure swings on size, ground conditions and the level of finish you choose.
The headline rate per square metre hides a lot. Groundworks are the biggest unknown: if your plot has soft ground, a high water table or existing drains running through the footprint, foundations get deeper and more expensive before a single wall goes up.
Kitchens and bathrooms add cost quickly because of the plumbing, electrics and units involved. A simple extra bedroom or living space is far cheaper per square metre than knocking through to create a fitted kitchen with an island and appliances.
Many single storey rear extensions in Scotland fall under permitted development, but this is not guaranteed, especially in conservation areas or if you are close to a boundary. It is worth checking with North Ayrshire Council before you commit to a design.
Even where planning permission is not needed, a building warrant almost always is. Budget for council fees, a structural engineer for any beams or steels, and drawings. These professional costs commonly add £1,500 to £4,000 on top of the build, and skipping them stores up trouble when you come to sell.
The cheapest quote is rarely the cheapest job. We always advise leaving a contingency of around ten per cent for the things nobody can see until the ground is opened up, such as old drains or poor existing footings on older Ayrshire properties.
Get everything written down in detail. A proper quote should spell out the specification, what is included, and what is treated as an extra. Vague quotes are where the unexpected bills come from, so ask for clarity on finishes, fittings and who supplies the kitchen.
For many families it works out better value than paying estate agent fees, legal costs and a higher mortgage, and it adds usable space to a home you already like. The sums depend on local house prices, so weigh the build cost against what moving would actually involve.
Most single storey extensions take around eight to sixteen weeks on site, depending on size and complexity. Wet weather, deep foundations and bespoke glazing with long lead times can extend that, so it is sensible to allow some flexibility in your timeline.
A well built extension usually adds value, particularly when it creates a larger kitchen or an extra bedroom, though the uplift varies by area and property type. The key is quality work with proper warrants in place, as buyers and surveyors will check the paperwork.
Tell us about the build or the joinery and we will come out and give you a free quote.
Tell us about your project and we will get you a free quote.