If you are pricing up an extension in Inverness or the wider Highlands, you will find plenty of national cost guides that simply do not reflect building here. Labour availability, transport to rural sites and our weather all shape the final figure. This guide sets out realistic ranges and the factors that move them, so you can budget with confidence before you speak to a builder.
As a broad guide, a straightforward single storey extension in the Highlands tends to come in between £2,200 and £3,000 per square metre for a good standard of finish. So a modest 20 square metre kitchen extension might sit somewhere between £44,000 and £60,000 before VAT, fees and fittings. Two storey extensions are usually more cost effective per square metre, often £1,900 to £2,600, because the roof and foundations serve two floors.
These figures are starting points, not quotes. A simple rectangular extension on level ground near Inverness will sit at the lower end. A complex design on a sloping rural plot with poor access can push well beyond the top of these ranges. Always get itemised quotes from two or three builders and compare what is actually included.
Location matters more here than almost anywhere else in the UK. If your home is in Inverness, Nairn or along the A96 corridor, trades and materials are close at hand. Head out towards Ullapool, Skye or the smaller glens and you are paying for travel time, delivery surcharges and sometimes overnight stays for specialist trades such as structural glazing installers.
Ground conditions are another big variable. Plenty of Highland plots sit on rock, which can mean breaking out foundations rather than simply digging them, while others have peat or high water tables that need engineered solutions. Exposure counts too. A site facing weather off the Moray Firth or open hillside may need upgraded wind loading calculations, more robust roofing details and better insulation, all of which add cost but pay back in comfort and running costs.
The build itself is only part of the picture. A building warrant from Highland Council is required for almost all extensions, and you will need architectural drawings and usually a structural engineer. Allow roughly 8 to 12 percent of the build cost for design fees, warrant fees and engineering. If your extension needs planning permission, which many do, factor in the application fee and a few months of lead time.
Then there are the finishing costs that vary hugely with taste. A kitchen can be £8,000 or £40,000. Underfloor heating, air source heat pump alterations, rooflights and hardwood flooring all add up. We always recommend holding a contingency of at least 10 percent for the unknowns, especially on older Highland properties where opening up a wall can reveal surprises.
Simple shapes are cheaper to build. Every corner, valley gutter and change of roofline adds labour and materials, so a clean rectangular footprint with a straightforward roof will stretch your budget furthest. Deciding your kitchen layout, glazing sizes and finishes before work starts also matters, because mid build changes are the most common cause of overspend.
Timing helps too. Good Highland builders book up months ahead, and starting groundworks in spring rather than midwinter reduces weather delays. Finally, make sure quotes are itemised and compare like with like. The cheapest headline figure often excludes items such as electrics, decoration or connection works that another quote has included.
Not always. Many single storey rear extensions fall under permitted development, but conservation areas, listed buildings and larger designs need planning permission from Highland Council. You will almost always need a building warrant regardless, so check both before committing money.
A single storey extension usually takes 10 to 16 weeks on site once foundations start, with two storey projects running 16 to 24 weeks. Add three to six months beforehand for design, planning and the building warrant, and be aware that winter weather can stretch external stages.
Usually yes, particularly extra bedrooms and open plan kitchen living space, which are in steady demand around Inverness. That said, value gained depends on your street and property type, so it is worth an informal chat with a local estate agent before spending at the top of your budget.