Annexe extensions across Highlands and Islands
Our design and build teams take on annexe extensions in Highlands and Islands, from the first measured survey through planning and building control to the finished room.
- Guide priceFrom £53,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Towns covered8
- Site visitFree on the mainland; islands by arrangement

How much does an annexe extension cost in Highlands and Islands?
Labour and material costs vary across the UK, so for Highlands and Islands we use our Scotland factor (×0.98). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Highlands and Islands: £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.
Do I need planning permission in Highlands and Islands?
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.
The planning position for a specific Highlands and Islands address depends on its history and any designations, which is why we check it at the first visit.
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.
What we take care of
- Separate or shared heating and hot water
- Fire separation and alarms to building regulations
- Design for accessibility: level thresholds, wider doors, walk-in shower
- Planning application describing ancillary use
Working in Highlands and Islands
Towns we cover in Highlands and Islands include Inverness, Fort William, Nairn, Thurso, Kirkwall, Lerwick, Stornoway, Dingwall. 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
Free site visits on the mainland; island and remote addresses by arrangement, with travel costs agreed first.
Site visit
It starts with a visit to your house to measure, check access and talk through ideas and budget.
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 Highlands and Islands
Do you cover all of Highlands and Islands?
Yes, across the whole of Highlands and Islands. Free site visits on the mainland; island and remote addresses by arrangement, with travel costs agreed first.
Do I need building regulations approval in Highlands and Islands?
Yes. Almost every extension needs it, whatever the planning route. In Scotland that means a building warrant before work starts.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Highlands and Islands, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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.
Can the annexe have its own front door?
Yes, many do, but it should still connect to the main house to stay clearly part of it.
Book a site visit in Highlands and Islands
We will measure up, check the planning position and give you honest guide figures.
- Free site visits on the mainland; islands and remote addresses by arrangement
- 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 site visit
Tell us a little about the project and we will arrange a time.