Side extensions for homes in Renfrewshire and Inverclyde
Our design and build teams take on side extensions in Renfrewshire and Inverclyde, from the first measured survey through planning and building control to the finished room.
- Guide priceFrom £21,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Towns covered7
- Site visitFree, no obligation

Side extension prices in Renfrewshire and Inverclyde
Prices below are for Renfrewshire and Inverclyde, using the Scotland factor of ×0.98. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Renfrewshire and Inverclyde: £1,720 to £3,330 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 2.5 m × 5 m 12 m² | £21,500 – £26,000 | £24,000 – £31,500 | £30,500 – £40,000 |
| 3 m × 6 m 18 m² | £30,500 – £37,500 | £36,000 – £47,000 | £45,500 – £60,000 |
| 3 m × 8 m 24 m² | £41,000 – £49,500 | £48,000 – £62,500 | £61,000 – £80,000 |
For a figure based on your own dimensions, use our guide-price tool.
What we take care of
- Foundations near boundaries and any drains
- New openings through the side wall
- Planning route checked or application made
- Structure, roof tied into the house
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.
Before any drawing is finalised we check whether the house is listed, in a conservation area or subject to an Article 4 direction.
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 Renfrewshire and Inverclyde
Towns we cover in Renfrewshire and Inverclyde include Paisley, Greenock, Newton Mearns, Renfrew, Barrhead, Johnstone, Erskine. Across Scotland, extensions follow Scottish planning and building standards, including the building warrant process, which we build into the programme from the start.
Our process, step by step
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
It starts with a visit to your house to measure, check access and talk through ideas and budget.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
Our team builds the extension, keeps you updated weekly and finishes with building control sign-off.
Common questions 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 you cover all of Renfrewshire and Inverclyde?
Yes, across the whole of Renfrewshire and Inverclyde. Site visits are free and there is no obligation.
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.
How much does a side extension cost?
Our guide range is about £1,720 to £3,330 per m² including VAT, depending on specification, so a standard 18 m² single-storey side extension lands around £36,000 to £47,000 in Renfrewshire and Inverclyde.
Can I build over my driveway?
Yes, if the foundations work and you keep any parking the council requires. Drains and services under drives are common, so we check before design.
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.