Double-storey extensions in Barrhead: design, approvals and build
Barrhead homeowners can use us for the whole double-storey extension project: survey, design, planning or permitted development checks, the building warrant and the build itself.
- Guide price in BarrheadFrom £37,000 inc VAT
- PlanningUsually planning permission; building warrant needed
- Build time16–24 weeks on site
- Postcode districtsG78

Planning rules that apply in Barrhead
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. Separately, almost every extension needs a building warrant from the council before work starts.
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.
Scotland has no Party Wall Act. Where work affects a shared wall or a neighbour's land, we agree access, protection and making good with your neighbour in writing before work starts.
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.
What we take care of
- Insulation, plastering, electrics and plumbing to finish
- Building regulations drawings and structural design
- Foundations sized for two floors
- Ground and first floor structure, roof tied into the existing roof
- Measured survey, design and planning drawings
- Breaking through at both levels, stairs and landing changes where needed
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.
What should I budget for a double-storey extension in Barrhead?
Prices below are for Barrhead, using the Scotland factor of ×0.98. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Barrhead: £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 |
Want a range for your exact size? The guide-price tool takes about a minute.
Extensions in and around Barrhead
Site visits are available across Barrhead (G78). We also work in nearby Paisley (3 miles), Newton Mearns (3 miles), Renfrew (5 miles), Johnstone (5 miles).
For homes towards Dunbartonshire, Clydebank is around 7 miles away. Across Scotland, extensions follow Scottish planning and building standards, including the building warrant process, which we build into the programme from the start.
What happens next
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
A designer visits, takes measurements and photos, and discusses layouts, budget and timing with you.
Design and approvals
We produce the drawings and structural design, and manage the approvals so they are in place before work starts.
Fixed written price
With the design and specification agreed, you get a fixed written price and a start date.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Barrhead
Do I need building regulations approval in Barrhead?
Yes. Almost every extension needs it, whatever the planning route. In Scotland that means a building warrant before work starts.
How long does a double-storey extension take to build in Barrhead?
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 Barrhead?
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.
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 Barrhead
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.