Double-storey extensions in Renfrewshire and Inverclyde
A double-storey extension in Renfrewshire and Inverclyde starts with the right design and the right approval route. We take care of both, then build it with our own project management.
- Guide priceFrom £37,000 inc VAT
- PlanningUsually planning permission; building warrant needed
- Towns covered7
- Site visitFree, no obligation

Planning and approvals in Renfrewshire and Inverclyde
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.
Homes in conservation areas, national scenic areas and listed buildings have tighter rules, so we always check the property's status and planning history before design starts.
Building close to a public sewer needs the agreement of Scottish Water, which we check during design.
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.
Applications are decided by your council as planning authority.
What is included
- Breaking through at both levels, stairs and landing changes where needed
- Measured survey, design and planning drawings
- Building regulations drawings and structural design
- Foundations sized for two floors
Double-storey extension prices in Renfrewshire and Inverclyde
Labour and material costs vary across the UK, so for Renfrewshire and Inverclyde we use our Scotland factor (×0.98). The ranges include VAT and exclude design, structural and council fees.
Typical rates in Renfrewshire and Inverclyde: £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 |
For a figure based on your own dimensions, use our guide-price tool.
Extensions in and around Renfrewshire and Inverclyde
Towns we cover in Renfrewshire and Inverclyde include Paisley, Greenock, Newton Mearns, Renfrew, Barrhead, Johnstone, Erskine. Scotland's housing includes sandstone villas, terraces and tenements in the cities and plenty of post-war and modern houses and bungalows elsewhere. A building warrant is needed before work starts.
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
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Your questions about a double-storey extension in Renfrewshire and Inverclyde
Will my neighbours in Renfrewshire and Inverclyde be involved?
If a planning application is needed, the council notifies neighbours. Where work is close to a shared boundary, we agree access and protection with them in writing.
Do I need building regulations approval in Renfrewshire and Inverclyde?
Yes. Almost every extension needs it, whatever the planning route. In Scotland that means a building warrant before work starts.
Do you cover all of Renfrewshire and Inverclyde?
Yes, across the whole of Renfrewshire and Inverclyde. Site visits are free and there is no obligation.
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 Renfrewshire and Inverclyde
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.