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.
In St Andrews, as anywhere in Fife, the price of a double-storey extension is driven mainly by size, materials and access. Across Scotland our guide sits at £58,000–£115,000 with VAT, but restricted parking, a narrow side passage or extra preparation can move the figure either way. That is why every price we give follows a visit to the house.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Postcodes
- KY16
- Planning rules
- Scotland
- Local area
- Fife
- Survey
- Free, with a written quote
How much does a double-storey extension cost in St Andrews?
Budgeting for a double-storey extension in St Andrews? 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 St Andrews |
|---|---|---|
| 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 |
What moves the price up or down:
- 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
Scope of the work
- 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
- Windows, external doors, plastering and internal doors
Local housing and a double-storey extension
Fife's East Neuk fishing villages are known for pantiled roofs and crow-stepped gables, and St Andrews has historic stone streets. Kirkcaldy and Dunfermline have Victorian sandstone housing and interwar estates, Glenrothes was built as a post-war new town, and former mining towns in central Fife have rows of cottages and post-war council housing.
The coast faces cold easterly winds and salt from the North Sea, and frost is common inland through the winter.
In St Andrews, as elsewhere in Fife, we take the building's age and construction into account before recommending anything, because both can change what is involved in a double-storey extension.
Do you need permission in St Andrews?
Planning law differs across the UK. For a home in St Andrews, it is the Scotland rules below that count, and we check them with the council ahead of any quote.
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.
What happens after you get in touch?
Survey and measure
First, someone visits your home in St Andrews to see the space, take measurements and note anything that could affect the work, such as access or the condition of what is there. There is no charge for this visit.
Written quote
After the survey we send a quote for a double-storey extension that fixes the price for the scope we've agreed. If you want to change materials or scope, we revise it in writing before anything is booked.
Plan and prepare
Once you accept, we agree start dates, order materials and deal with any planning, building control or neighbour notices the job needs. You'll know who is coming and when before work begins.
Finish and handover
Our trades complete a double-storey extension while your point of contact keeps you updated. When everything is finished, we clear the site, take away waste and go through the result with you before handover.
Working with SK Home Improvements
Questions about a double-storey extension in St Andrews
Can you combine a double-storey extension with other work?
Yes. Because we manage several trades under one contract, we can plan a double-storey extension alongside other work on your St Andrews home, such as new windows with rendering, or a kitchen refit with an extension. Combining jobs can reduce repeat set-up such as scaffolding, skips and access, and every element is listed and priced in the same written quote.
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.
Can we live at home while it is built?
Most families stay at home during a double-storey extension. The new structure is built outside first, and we only break through into the existing rooms near the end, usually one floor at a time. Upstairs, this may mean a bedroom is out of use for a week or two. We fit dust screens, protect floors and stairs, and plan any time without water or power in advance.
Do you cover Dundee, Carnoustie and Glenrothes?
Yes. As well as St Andrews, we cover Dundee, Carnoustie and Glenrothes and the rest of Fife. Our coverage is UK-wide, so the process is the same wherever you are: a free site survey, a quote in writing that fixes the price for the agreed scope, and one point of contact while the work is planned and carried out.
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.
Also covering areas around St Andrews
We welcome enquiries from all KY16 postcodes in St Andrews, plus Dundee, Carnoustie and Glenrothes. Each one gets the same survey at no charge and a written price fixed for the work described.