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.
From Stirling, Falkirk, Alloa and Grangemouth to the quieter corners of Stirling, Falkirk and Clackmannanshire, homeowners can book a free survey for a double-storey extension. We look at the building, agree the scope, then send a quote in writing that fixes the cost of that scope. Work follows the rules for Scotland, and our published range for Scotland, £58,000–£115,000 with VAT, gives you a sense of budget before we visit.
- Guide price
- £58,000–£115,000 inc VAT
- Time on site
- 14–22 weeks on site
- Planning rules
- Scotland
- Price level
- About 4% below the national guide
- Towns listed
- 4
- Survey
- Free, with a written quote
How much does a double-storey extension cost in Stirling, Falkirk and Clackmannanshire?
No two jobs cost exactly the same, but the ranges below give a fair picture of a double-storey extension in Stirling, Falkirk and Clackmannanshire. Pricing for Scotland runs about 4% below the national guide, and the overall guide is £58,000–£115,000 with VAT included. We'll confirm your figure after surveying the property for free.
| Type of job | What it usually involves | Guide in Stirling, Falkirk and Clackmannanshire |
|---|---|---|
| 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
What do you get?
- Insulated cavity walls with brick or render to match the house
- 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
- Windows, external doors, plastering and internal doors
- Building control inspections and completion certificate
Housing across 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.
Stone homes commonly need repointing and slate roof repairs, and harled houses need re-rendering. Semis and bungalows suit extensions and loft conversions, and newer homes take garage conversions and driveways.
The Forth valley is prone to frost and low-lying flood risk, while the Ochil hills bring heavier rain to the Hillfoots.
Do you need permission in Stirling, Falkirk and Clackmannanshire?
Planning law differs across the UK. For a home in Stirling, Falkirk and Clackmannanshire, 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.
The four stages
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.
Written quote
Next you receive a written quote with a fixed price for the agreed specification. It lists what is included, what is not, and how payments are staged, so you can compare it properly.
Dates and permissions
Before anyone starts, we confirm the programme in writing, check whether consents are required and arrange deliveries. If a skip or scaffolding on the road needs a permit, we apply for it.
The work itself
On site, the agreed plan is followed and any change is put in writing first. At completion we do a final clean, go through the snagging list with you and leave you with the relevant documents.
What you can expect from us
Questions about a double-storey extension in Stirling, Falkirk and Clackmannanshire
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.
Which postcodes in Stirling, Falkirk and Clackmannanshire do you cover?
We cover FK7, FK1, FK10 and FK3, 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.
Is the price fixed?
Yes, for the specification we agree. Your written quote sets out exactly what is included at a fixed price. It only changes if you ask for something different, or if a problem the survey could not reasonably reveal later needs extra work. In either case we explain the change and confirm it in writing before going ahead.
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.
Is a double-storey extension better value than single-storey?
A double-storey extension usually gives better value per square metre than a single-storey one, because the same foundations and roof serve twice the floor area. The overall cost is higher, and planning can be harder because of the effect on neighbours. If you might want an extra bedroom later, building both floors now avoids a second round of disruption and scaffolding.
Towns in Stirling, Falkirk and Clackmannanshire
Our coverage for a double-storey extension in Stirling, Falkirk and Clackmannanshire includes the towns listed here. Each page explains guide costs, typical timings and the neighbouring places we also serve.