Thurso annexe extensions, designed and built
We take on annexe extensions in Thurso by arrangement. Because of travel and logistics, we agree the programme and any travel costs in writing before the survey.
- Guide price in ThursoFrom £53,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Build time16–24 weeks on site
- Postcode districtsKW14

Who an annexe extension suits
- Multi-generational families
- Homes with a large side or rear garden
- Relatives who need support close by
Accessibility is cheaper to design in than to retrofit. Level access, a 900 mm door width, a level-access shower and space to turn a wheelchair can all be planned into the footprint for little extra cost.
How much does an annexe extension cost in Thurso?
Prices below are for Thurso, using the Scotland factor of ×0.98. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Thurso: £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.
Extensions in and around Thurso
We cover Thurso and the postcode districts KW14. Island and remote projects are planned individually, with travel, deliveries and accommodation for the team agreed before the survey.
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.
Planning rules that apply in Thurso
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
In Scotland a building warrant from the council is needed before work starts on almost any extension, and a completion certificate is issued when the work is accepted. Building standards are set in the Scottish technical handbooks.
Applications are decided by your council as planning authority.
From first visit to completion
Visits to Thurso are arranged around travel; we confirm any travel costs in writing before the survey.
Site visit by arrangement
First, a site visit: we look at the house, garden, access and drains and listen to what you need.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions in Thurso
Do you cover all of Thurso?
Yes. We cover Thurso and the surrounding parts of Highlands and Islands. Projects here are taken on by arrangement because of travel, and any travel costs are agreed before the survey.
How long does an annexe extension take to build in Thurso?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
Do I need building regulations approval in Thurso?
Yes. Almost every extension needs it, whatever the planning route. In Scotland that means a building warrant before work starts.
How much does an annexe extension cost?
Our guide range is about £1,960 to £3,720 per m² including VAT. A one-bedroom annexe of about 35 m² is typically £82,000 to £103,000 at standard spec in Thurso.
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.
Talk to us about a project in Thurso
We will talk through the project, the planning position and how we would organise the visit and the build.
- Site visit arranged around travel, costs agreed first
- 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 .
Send us your project details
Tell us a little about the project and we will arrange a time.