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.
Whatever type of house you own in Alloa, we start by looking at how a double-storey extension would fit it rather than offering a standard package. We cover FK10 and neighbouring places such as Stirling, Grangemouth and Falkirk. One named person looks after you from survey to handover, and nothing is booked until you hold our figure in writing, fixed for the work described.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- FK10
- Planning rules
- Scotland
- Local area
- Clackmannanshire
- Survey
- Free, with a written quote
Double-storey extensions prices in Alloa
Here is how the guide price for a double-storey extension breaks down in Alloa. We start from national figures and adjust for Scotland, which comes out about 4% below the national guide. The resulting range, VAT included, is £58,000–£115,000, and a survey, at no cost to you, firms it up.
| Type of job | What it usually involves | Guide in Alloa |
|---|---|---|
| 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 |
Your price depends mostly on:
- Combined floor area across both storeys
- How the new roof joins the existing roof
- Bathrooms, en-suites and plumbing on the upper floor
- Scaffolding duration, access and the level of finishes
What’s included?
- Groundworks, foundations and below-ground drainage
- 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 control inspections and completion certificate
Homes in Stirling, Falkirk and Clackmannanshire
Stirling's old town has historic stone buildings, with Victorian villas in the King's Park area and newer estates around the city. Falkirk and Grangemouth have industrial-era terraces and post-war housing, and Alloa and the Hillfoots villages in Clackmannanshire mix stone cottages, mill-era housing and harled council homes.
The Forth valley is prone to frost and low-lying flood risk, while the Ochil hills bring heavier rain to the Hillfoots.
Building traditions across Stirling, Falkirk and Clackmannanshire also raise conservation and planning questions, so we check those for a double-storey extension in Alloa at the survey stage.
Planning and building rules in Alloa
Each UK nation sets its own consent rules, and Alloa is in Scotland. What follows is a plain summary; we check the specifics for your property with the council before pricing anything.
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.
The four stages
A visit to your home
It starts with a survey at the property, free of charge. We check condition, access and services, ask how you want the finished result to look, and answer any questions you have about a double-storey extension.
Your fixed price
You get the price in writing, itemised so you can see where the money goes. As long as the specification stays the same, that is the price you pay for a double-storey extension.
Plan and prepare
We handle the paperwork side: checking whether planning permission or building control approval is needed, submitting applications where they are, and scheduling the trades and materials around your dates.
The work itself
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.
How we work
Questions about a double-storey extension in Alloa
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.
Which postcodes in Alloa do you cover?
We cover FK10, along with the rest of Stirling, Falkirk and Clackmannanshire. 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.
Do I need planning permission for a two-storey extension?
Most two-storey extensions need planning permission, but it depends on the size, height and position, your home's location, whether it is listed or in a conservation area, and which UK nation you are in. In England, a two-storey rear extension can sometimes be built under permitted development if it is no deeper than 3m and at least 7m from the rear boundary. We check what applies before quoting.
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.
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.
Also covering areas around Alloa
Alloa and its FK10 postcodes are part of our coverage. Homeowners in Stirling, Grangemouth and Falkirk can also book a free survey with us and receive a written price for their job.