Two-storey rear extensions in Argyll and Bute
If you're in Argyll and Bute and weighing up a two-storey rear extension, start here: guide costs for Scotland, the approvals you'll need and how we work.
Argyll and Bute at a glance
- Nation
- Scotland
- Price region
- Scotland
- Postcode areas
- G, PA
- Towns covered
- 8 listed below, plus surrounding villages
- 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.
- Site visits
- Free on the mainland; island and remote addresses by arrangement, with travel costs agreed first
What a two-storey rear extension involves
A two-storey rear extension is a new two-floor addition built onto the back of your house, usually giving a larger kitchen or living space on the ground floor and one or two bedrooms or a bathroom above. Because both floors share one set of foundations and one roof, it adds a lot of floor space for the garden it uses. In some cases it can be built under permitted development, depending on where you live.
Across Argyll and Bute we cover Helensburgh (G84), Dunoon (PA22), Oban (PA34), Rothesay (PA20), Campbeltown (PA28) and Isle of Islay (PA43), plus the smaller places around them.
Guide price in Scotland
Our guide for Scotland is £1,880–£2,540 per m² including VAT. On a project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that puts a two-storey rear extension in Argyll and Bute at roughly £52,500–£71,000. Keep a contingency of around 10% for things nobody can see until the ground is opened up.
| Spec | Per m² | Typical project |
|---|---|---|
| Essential | £1,730–£2,330 per m² | £48,500–£65,500 |
| Standard | £1,880–£2,540 per m² | £52,500–£71,000 |
| Premium | £2,260–£3,050 per m² | £63,000–£85,500 |
Rules in Scotland
In Scotland, a two-storey rear extension is only permitted development under Class 1B if no part of it is within 10 m of any boundary, it is no higher than the house and the house is not in a conservation area. Most gardens cannot meet the 10 m test, so expect 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.
There is no Party Wall Act in Scotland. Shared walls and boundaries are governed by title deeds and common law, so we speak to neighbours early and record the condition of shared structures.
Getting the design right
Depth and neighbours' light
Councils check that a two-storey rear extension does not take too much light or outlook from neighbouring windows, and many use a 45-degree line drawn from the nearest habitable window. We test this at sketch stage, so the depth you are shown is one that can realistically be approved.
Foundations and drains
Foundations for two storeys carry more load than a single storey and may need to go deeper near trees or on clay. Rear extensions often sit near drains, so we check sewer records early, as building over or near a public sewer may need the water company's agreement.
How we work in Argyll and Bute
Visit and first ideas
One of our team visits your house in Argyll and Bute, checks the walls, roof and drains, and sketches out options with you.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Scotland before drawing in detail.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Towns we cover in Argyll and Bute
Two-storey rear extensions in Argyll and Bute: questions
How much does a two-storey rear extension cost in Argyll and Bute?
In Scotland our guide is £1,880–£2,540 per m² including VAT, so about £52,500–£71,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.
Will a two-storey rear extension block my neighbour's light?
It can if it is too deep or too close to the boundary, which is why councils look closely at its effect on neighbouring windows and gardens. We test the design against light and outlook early, keep the first floor shorter or set in where needed, and use a hipped roof to reduce bulk on the boundary side.
Will I need planning permission in Argyll and Bute?
Argyll and Bute is in Scotland. 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.
Neighbouring areas
- Two-storey rear extensions in Renfrewshire and Inverclyde
- Two-storey rear extensions in Ayrshire
- Two-storey rear extensions in Glasgow and Dunbartonshire
- Two-storey rear extensions in Lanarkshire
All extension services in Argyll and Bute · About two-storey rear extensions
Ready to see what a second storey could do for your home?
Book a site visit: free on the mainland, by arrangement on islands and remote addresses. We'll look at your house, talk through options and explain the approvals you'd need.