Double-storey extensions in Forth Valley
If you live in Forth Valley and want more space without moving, a double-storey extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide priceFrom £37,000 inc VAT
- PlanningUsually planning permission; building warrant needed
- Towns covered4
- Site visitFree, no obligation

Towns in Forth Valley
What we take care of
- Building regulations drawings and structural design
- Householder planning application where needed
- Foundations sized for two floors
- Insulation, plastering, electrics and plumbing to finish
- Breaking through at both levels, stairs and landing changes where needed
- Measured survey, design and planning drawings
The roof is what makes a two-storey extension look right or wrong. We match the pitch and materials of the main house wherever possible and plan the upstairs layout around the existing landing so the new rooms feel original rather than bolted on.
Guide prices for Forth Valley
Labour and material costs vary across the UK, so for Forth Valley we use our Scotland factor (×0.98). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Forth Valley: £1,520 to £2,940 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m, two floors 24 m² | £37,000 – £44,500 | £42,000 – £55,500 | £54,000 – £71,000 |
| 4 m × 4 m, two floors 32 m² | £48,500 – £58,500 | £56,000 – £74,000 | £72,000 – £94,500 |
| 4 m × 6 m, two floors 48 m² | £72,500 – £87,500 | £84,500 – £111,000 | £108,000 – £141,500 |
Try the guide-price tool to see a range for your own size and finish.
Planning rules that apply in Forth Valley
In Scotland, householder permitted development rules (Class 1A for single-storey ground-floor extensions and Class 1B for extensions of more than one storey) allow some smaller extensions without a planning application, within limits on depth, height and distance from the boundary. Conservation areas and listed buildings are more restricted.
In a conservation area or national scenic area the householder permitted development rights are more limited, listed homes need listed building consent, and if rights have been removed by a condition or direction, any extension needs an application.
In Scotland a building warrant from the council is needed before work starts on almost any extension, and a completion certificate is issued when the work is accepted. Building standards are set in the Scottish technical handbooks.
Building close to a public sewer needs the agreement of Scottish Water, which we check during design.
Applications are decided by your council as planning authority.
Covering Forth Valley
Towns we cover in Forth Valley include Stirling, Falkirk, Alloa, Grangemouth. Across Scotland, extensions follow Scottish planning and building standards, including the building warrant process, which we build into the programme from the start.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Forth Valley home, measure up, talk through what you want and check the planning position.
Design and approvals
Once the layout is agreed, we deal with the council: planning permission or written confirmation that none is needed, plus building control.
Fixed written price
We confirm the build price in writing, based on the approved drawings and the finishes you have chosen.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Questions people ask about double-storey extensions
How long does a double-storey extension take to build in Forth Valley?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 8–16 weeks design and approvals.
Who do I contract with for a double-storey extension in Forth Valley?
Your contract is with S&K Property Investments and Improvement Ltd, which designs and manages the project and the build teams who carry it out.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Forth Valley, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Is a two-storey extension cheaper per square metre?
Usually. Our guide range is about £1,520 to £2,940 per m² of new floor area including VAT, compared with £1,720 to £3,330 per m² for single-storey work, because the foundations and roof are shared across two floors.
Book a free site visit in Forth Valley
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.