How Much Does a House Extension Cost in Inverness?

Typical extension costs around Inverness

As a rough guide for 2026, a single storey extension in the Inverness area tends to cost somewhere between £2,200 and £3,300 per square metre of new floor space, built, finished inside and including VAT. A basic specification on an easy, level site sits at the lower end. Large areas of glazing, a vaulted ceiling or awkward ground push it towards the top.

In round numbers, that works out roughly as follows. These are guide ranges, not quotes, and your own figure depends on the design, the site and the finish you choose.

• Small rear extension of 15 to 20 square metres: roughly £40,000 to £65,000
• Kitchen and family room extension of 30 to 40 square metres: roughly £75,000 to £125,000
• Two storey extension of 40 to 50 square metres across both floors: roughly £90,000 to £150,000
• Sunroom or garden room with a lot of glazing: roughly £35,000 to £60,000
• A new fitted kitchen or bathroom is usually extra, often £8,000 to £25,000 depending on the units and appliances

What makes Highland prices different

Building here is not the same as building in a flat suburb further south, and a few local conditions have a real effect on price.

• Sloping plots: much of the south side of the city, including Lochardil, Milton of Leys and Westhill, sits on a slope. That can mean deeper foundations, retaining walls or steps, which add thousands before a wall goes up.
• Ground conditions: rock, peat or soft clay only show up once the digging starts. A trial pit at the design stage is cheap insurance.
• Distance: jobs in Nairn, Beauly, the Black Isle or Drumnadrochit are straightforward. Further out towards the west coast or up into Sutherland, travel time and delivery charges for concrete, timber and skips rise noticeably.
• Rural services: if your home has a septic tank or oil heating, adding bedrooms or a bathroom may mean upgrading the tank or boiler.
• Older stone houses: in the Crown and Riverside conservation areas, matching natural stone, slate and timber windows costs more than render and concrete tiles.
• Weather: exposed sites need robust detailing against wind-driven rain, and winter working can slow progress.

Permissions and professional fees

Almost every extension needs a building warrant from Highland Council before work starts, whether or not it needs planning permission. The warrant fee is on a sliding scale based on the estimated value of the work, so it grows with the size of the project.

Many modest rear extensions fall under permitted development and avoid a planning application, but homes in conservation areas, listed buildings and larger or side extensions often need one. Allow for drawings, a structural engineer and the council fees on top of the build cost. For a typical domestic extension these commonly come to between £3,000 and £8,000 in total, and more for a complex or listed property.

How to keep the budget under control

Most overspends come from changes made after work has begun, not from the original price. A little discipline at the planning stage makes the biggest difference.

• Keep the shape simple. A plain rectangle with a straightforward roof is far cheaper than corners, steps and valleys.
• Put new kitchens and bathrooms close to existing drains where you can.
• Choose standard window and door sizes, and settle on finishes before the build starts.
• Ask for a written, itemised quote so you can compare builders like for like, and check what is excluded.
• Hold back a contingency of 10 to 15 per cent for surprises in the ground or the existing house.