Renfrew annexe extensions, designed and built
If you live in Renfrew and want more space without moving, an annexe extension is one of the most practical ways to get it. We handle the drawings, approvals and the build.
- Guide price in RenfrewFrom £53,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Build time16–24 weeks on site
- Postcode districtsPA1, PA4
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.
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.
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.
Working in Renfrew
Site visits are available across Renfrew (PA1, PA4). Neighbouring towns we cover include Erskine (3 miles), Paisley (3 miles), Barrhead (5 miles), Johnstone (6 miles).
Clydebank, in Dunbartonshire, is roughly 2 miles from Renfrew and also on our list. Across Scotland, extensions follow Scottish planning and building standards, including the building warrant process, which we build into the programme from the start.
Annexe extension prices in Renfrew
These guide figures apply our Scotland adjustment (×0.98) to national rates. They include VAT at 20% and cover the build itself; design and council fees are listed separately.
Typical rates in Renfrew: £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.
When an annexe extension makes sense
- Homes with a large side or rear garden
- Multi-generational families
- Relatives who need support close by
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
We visit your Renfrew home, measure up, talk through what you want and check the planning position.
Design and approvals
We draw the design, agree it with you and handle planning or permitted development checks and building regulations.
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
We build it with one project manager, book the building control inspections and hand over the completion certificate.
Common questions in Renfrew
Do I need building regulations approval in Renfrew?
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 Renfrew?
Yes. We cover Renfrew and the surrounding parts of Renfrewshire and Inverclyde. Site visits are free and there is no obligation.
Will my neighbours in Renfrew 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 Renfrew
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.