Annexe extensions for homes in Renfrewshire and Inverclyde
Planning an annexe extension in Renfrewshire and Inverclyde? We survey the house, work out the planning route, draw the design and build it, so you deal with one team from the first visit to the completion certificate.
- Guide priceFrom £53,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Towns covered7
- Site visitFree, no obligation
Covering 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.
Who an annexe extension suits
- Relatives who need support close by
- Multi-generational families
- Homes with a large side or rear garden
Accessibility is cheaper to design in than to retrofit. Level access, a 900 mm door width, a level-access shower and space to turn a wheelchair can all be planned into the footprint for little extra cost.
Will the council need to approve it?
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.
Applications are decided by your council as planning authority.
How much does an annexe extension cost 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: £1,960 to £3,720 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| Studio annexe 25 m² | £53,500 – £67,500 | £58,500 – £73,500 | £73,500 – £93,500 |
| One-bedroom annexe 35 m² | £68,500 – £86,000 | £82,000 – £103,000 | £102,500 – £130,500 |
| Larger annexe 45 m² | £88,000 – £110,500 | £105,500 – £132,500 | £132,000 – £168,000 |
Want a range for your exact size? The guide-price tool takes about a minute.
From first visit to completion
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 Renfrewshire and Inverclyde home, measure up, talk through what you want and check the planning position.
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
The price is fixed in writing once the design is settled, with a clear programme and payment stages.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Common questions in Renfrewshire and Inverclyde
How long does an annexe extension take to build in Renfrewshire and Inverclyde?
On site, typically 16 to 24 weeks once approvals are in place. Before that, allow 10–16 weeks design and approvals.
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Renfrewshire and Inverclyde, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
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.
Can the annexe have its own front door?
Yes, many do, but it should still connect to the main house to stay clearly part of it.
Does an annexe extension need planning permission?
Usually yes, because of its size and the way it will be used. Councils check that it stays ancillary to the main house, so the application must describe the use clearly.
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.