First-floor extensions in Thurso
If you live in Thurso and need more room without moving, a first-floor extension is worth a serious look. We handle the drawings, approvals, structure and build.
We take on projects in Thurso by arrangement. Site visits here aren't free as standard, and we'll agree travel costs with you in writing first.
What we'd confirm first for a project in Thurso.
- Postcode districts
- KW12 and KW14
- County / area
- The Highlands, Moray and Islands, Scotland
- Price region
- Scotland
- Guide price
- £23,500–£34,000 (£1,690–£2,440 per m²)
- Approval route
- Planning permission is usually needed: Class 1B permitted development only applies if every part of the extension is at least 10 m from all boundaries. A building warrant is needed before work starts.
- Nearest towns
- Wick (18.9 miles), Tain (57.3 miles), Lossiemouth (60.9 miles)
- Distance to Inverness
- about 81.1 miles
- First visit
- By arrangement
About a first-floor extension
A first-floor extension is a new upstairs room built on top of an existing single-storey part of your house, such as a rear kitchen extension, a utility or a side annexe. It adds a bedroom, bathroom or study without enlarging the footprint. Whether it works depends mainly on whether the walls and foundations below can carry the extra load.
Thurso sits about 81.1 miles from Inverness. Closer to home, Wick is 18.9 miles away and Tain 57.3 miles.
What it costs in Thurso
For budgeting in Thurso, allow around £23,500–£34,000 for a first-floor extension with 4 m × 3.5 m of new first-floor space (14 m²). That's based on £1,690–£2,440 per m² including VAT for Scotland. Keep a contingency of around 10% for things nobody can see until the ground is opened up.
| Spec | Per m² | 4 m × 3.5 m of new first-floor space (14 m²) |
|---|---|---|
| Essential | £1,560–£2,250 per m² | £22,000–£31,500 |
| Standard | £1,690–£2,440 per m² | £23,500–£34,000 |
| Premium | £2,030–£2,930 per m² | £28,500–£41,000 |
Planning and building standards in Thurso
In Scotland, permitted development for extensions of more than one storey (Class 1B) needs at least 10 m to every boundary and no part higher than the house. Most first-floor extensions cannot meet the 10 m test, so plan for a householder application (£371, decided within two months) and a building warrant before work starts.
Approval in Scotland: Householder planning application: £371. Councils have two months to decide a local planning application.
Building standards: A building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks.
Design points for Thurso homes
Escape and fire safety
A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and 450 mm high, with the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs.
Can the existing structure take it?
Many single-storey extensions were built with foundations, walls and lintels sized for one storey. We find out what is there with trial holes and, where available, the original building standards drawings. The engineer then decides whether to reuse, strengthen or rebuild parts of the structure.
How we'd run your project
Visit by arrangement
We agree a visit to your home in Thurso and any travel costs with you in writing first, then look at the structure, access and boundaries.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Thurso.
Technical design
We prepare the building warrant drawings, structural calculations and specification so the build price can be fixed.
Finish and certify
Second fix, plastering and making good, then the council's final building standards inspection and the completion paperwork.
Questions about first-floor extensions in Thurso
How much does a first-floor extension cost in Thurso?
Our guide for Scotland, which covers Thurso, is £1,690–£2,440 per m² including VAT. A typical project with 4 m × 3.5 m of new first-floor space (14 m²) comes to about £23,500–£34,000. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
Which postcodes do you cover around Thurso?
We cover Thurso (KW12 and KW14) and nearby places including Wick, Tain and Lossiemouth, plus the rest of the Highlands, Moray and Islands. Visits and projects in Thurso are by arrangement, with travel costs agreed in writing first.
Who handles building standards for a project in Thurso?
We handle it as part of the project. What's needed in Scotland: a building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.
Can I build on top of my existing single-storey extension?
Often yes, but only after the structure has been checked. Foundations, walls and lintels built for one storey may not carry two. We dig trial holes, look for the original a building warrant and ask the structural engineer to confirm what can stay, what needs strengthening and what must be rebuilt.
What happens to the room below while the first floor is built?
The old roof is removed, so the room below is exposed for a short period. We fit temporary weather protection, plan the work so the roof comes off only when the new structure is ready, and agree with you which rooms will be out of use and for roughly how long.
Nearby
The same service in neighbouring towns:
Other extensions in Thurso
- Rear
- Side
- Wraparound
- Part two-storey
- Over a garage
- Semi-detached
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Thurso · First-floor extensions across the Highlands, Moray and Islands
The quickest next step is a visit. We'll look at your house in Thurso and give you an honest view of the options.