Two-storey side extensions in Argyll and Bute
If you're in Argyll and Bute and weighing up a two-storey side 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 side extension involves
A two-storey side extension is a new two-floor addition built into the space beside your house, often over a driveway or side passage. It typically adds one or two bedrooms upstairs and a utility, study or larger kitchen below, without giving up rear garden.
Towns in Argyll and Bute include Helensburgh (G84), Dunoon (PA22), Oban (PA34), Rothesay (PA20), Campbeltown (PA28) and Isle of Islay (PA43). If yours isn't listed, we still cover it.
Guide price in Scotland
Using our Scotland rates, a two-storey side extension with a 3 m × 7 m footprint on two floors (42 m² of new floor space) comes to about £81,000–£108,500, including VAT. Bigger or more glazed designs cost more per m². Design fees, structural calculations and approval fees are separate and listed on our prices page.
| Spec | Per m² | Typical project |
|---|---|---|
| Essential | £1,770–£2,380 per m² | £74,500–£100,000 |
| Standard | £1,930–£2,580 per m² | £81,000–£108,500 |
| Premium | £2,310–£3,100 per m² | £97,000–£130,500 |
Rules in Scotland
In Scotland, a two-storey side extension is only permitted development under Class 1B if no part is within 10 m of any boundary and it is not on an elevation fronting a road. Side extensions rarely meet this, so plan for a householder application (£371, decided within two months) and a building warrant from the council 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
Avoiding a terracing effect
Where semi-detached houses sit close together, side extensions on neighbouring houses can join up and turn a row of pairs into a terrace. Many councils ask for a gap to the boundary at first floor to stop this, so we check local guidance before fixing the width.
Side windows, boundaries and gutters
Upstairs windows in the side wall face the neighbour, so they are usually obscure-glazed and fixed, or left out. Building close to the boundary also raises questions about foundations, overhanging gutters and access for maintenance, so we design the eaves and gutter to stay within your land.
How we work in Argyll and Bute
Understand the brief
At your home in Argyll and Bute we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Structure and building standards
A structural engineer sizes the foundations and steels, and we get a building warrant before work starts.
Finish and certify
Second fix, plastering and making good, then the council's final building standards inspection and the completion paperwork.
Towns we cover in Argyll and Bute
Two-storey side extensions in Argyll and Bute: questions
How much does a two-storey side extension cost in Argyll and Bute?
In Scotland our guide is £1,930–£2,580 per m² including VAT, so about £81,000–£108,500 for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.
Can I build a two-storey side extension over my driveway?
Yes, if the drive is wide enough for a useful room and the council accepts the design. You may lose off-road parking, which some councils weigh up, and the foundations need to suit the ground below. We check parking, drains and meter positions at the free site visit before any drawings are prepared.
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 side extensions in Renfrewshire and Inverclyde
- Two-storey side extensions in Ayrshire
- Two-storey side extensions in Glasgow and Dunbartonshire
- Two-storey side extensions in Lanarkshire
All extension services in Argyll and Bute · About two-storey side 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.