A double-storey extension adds two floors of new space to your house in one build, typically a larger kitchen or living room downstairs with an extra bedroom, bathroom or en-suite above, sharing one set of foundations and one roof.
If you live in Dunoon and are weighing up a double-storey extension, the starting point is a visit to measure up and talk through what you want, which costs nothing. We cover homes across PA23, and a typical project of this kind in Scotland lands somewhere in the £58,000–£115,000 bracket, including VAT. The exact figure depends on size, access and the finish you choose.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- PA23
- Planning rules
- Scotland
- Local area
- Argyll and Bute
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Dunoon?
Budgeting for a double-storey extension in Dunoon? The numbers below include VAT and are adjusted for Scotland, where costs are about 4% below the national guide. The headline range is £58,000–£115,000. Nothing is final until we have measured up at a free survey and agreed the specification with you.
| Type of job | What it usually involves | Guide in Dunoon |
|---|---|---|
| Small (15–20m² total) | A compact rear or side extension adding a small room on each floor. | £38,500–£62,000 |
| Typical (30–40m² total) | A larger kitchen or living room below with a double bedroom or en-suite above. | £58,000–£115,000 |
| Large (50m² plus total) | Wide or deep extensions, often with a new bathroom, steelwork and high-spec glazing. | £96,000–£173,000 |
The main things that change the figure:
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Foundation depth, ground conditions and drains to divert
- Scaffolding duration, access and the level of finishes
What’s included?
- Groundworks, foundations and below-ground drainage
- Insulated cavity walls with brick or render to match the house
- First-floor joists, stud walls and new openings upstairs
- Roof structure tied into the existing roof, tiled to match
- Scaffolding for the full build, erected and inspected
- Electrics, plumbing and heating by qualified trades, with certificates
Building in Dunoon
Much of Argyll and Bute is rural and coastal, with whitewashed or harled stone cottages, slate roofs and island homes. Helensburgh has Victorian villas, Oban, Dunoon and Rothesay have Victorian seaside terraces, and post-war and newer housing surrounds the main towns.
Stone cottages need lime harling, repointing and slate roof repairs; villas may need roof and window renewal. Island and remote properties need the programme planned around ferries, deliveries and weather.
Building traditions across Argyll and Bute also raise conservation and planning questions, so we check those for a double-storey extension in Dunoon at the survey stage.
Do you need permission in Dunoon?
Homes in Dunoon come under the regulations for Scotland, summarised below. We don't rely on general rules alone: we confirm the position for your address with the council before a quote goes out.
In Scotland, extensions of more than one storey are only permitted development in narrow cases (Class 1B, well away from the boundary they face and outside conservation areas), so most need planning permission.
A building warrant is required before work starts. Scotland has no Party Wall Act; neighbour and title issues are handled under general law.
Rules change and every property is different, so we check the planning history and constraints for your address before we quote.
From survey to handover
We look at the job
We arrange a free site survey on a date convenient to you. We measure up, look at the existing structure and access, and discuss your plans for a double-storey extension so the price reflects your home.
Your fixed price
We put everything into a written, fixed-price quote: the specification, what's excluded, staged payments and the expected time on site. Take whatever time you need to decide; there's no pressure to commit.
Booking the work
With the quote agreed, we book the work in and handle preparation: permissions where needed, building control notifications, material orders and access arrangements for your Dunoon property.
Build and hand over
The work is carried out to the agreed specification, with floors and furniture protected and the site kept tidy. At the end we clean up, walk through the finished job with you and hand over any certificates.
Working with SK Home Improvements
Double-storey extensions in Dunoon: questions
What happens at the survey?
We visit your home at a time that suits you, look at the area involved, take measurements and check access, condition and any services that might be affected. We talk through what you want from a double-storey extension, explain the options and answer questions. There is no charge and no obligation; afterwards we send a written quote.
Can the new upstairs room have its own bathroom?
A new upstairs room can usually have an en-suite, provided waste pipes can reach the soil stack or a new one can be installed. Running the waste pipe to the right falls is the main design question, and a pumped system is an option where gravity will not work. We plan bathroom positions at the design stage so pipes, ventilation and insulation are built in rather than added later.
Which postcodes in Dunoon do you cover?
We cover PA23, along with the rest of Argyll and Bute. If your postcode is not listed, get in touch anyway: our coverage is UK-wide, and we can usually arrange a survey wherever you live. Enter your postcode in the guide-price tool or contact form and we will confirm.
How long does a double-storey extension take?
A double-storey extension typically takes 14–22 weeks on site, depending on size, roof design and weather. Foundations and ground-floor walls come first, then the first-floor joists, upper walls and roof. Once it is weathertight, electrics, plumbing, plastering and finishes follow. Allow extra time beforehand for drawings, calculations and approvals. We give you a stage-by-stage programme with your quote.
Will the extension affect my neighbours?
A double-storey extension can affect neighbours' light, outlook and privacy, which is why planning departments look closely at height, depth and window positions. Side windows facing neighbours often need obscure glass. Work near a shared wall may also need party wall notices; the Party Wall etc. Act 1996 applies in England and Wales only. We talk through these points early so the design is realistic.
Nearby towns
We survey and quote throughout Dunoon's PA23 postcodes and in surrounding places such as Greenock, Helensburgh and Isle of Bute. The process and pricing approach are identical in each of them.

