Extra bedroom and en-suite extensions in Johnstone
For an extra bedroom and en-suite extension in Johnstone, the first questions are always the same: how big, which approvals, and what it will cost. This page answers all three for Renfrewshire and Inverclyde.
Johnstone: the key facts for this kind of project.
- Postcode districts
- PA5, PA9 and PA10
- County / area
- Renfrewshire and Inverclyde, Scotland
- Price region
- Scotland
- Guide price
- £52,500–£71,000 (£1,880–£2,540 per m²), plus £5,500–£11,000 for the en-suite
- Approval route
- Planning permission is usually needed: Class 1B permitted development only applies if every part of the extension is at least 10 m from all boundaries. A building warrant is needed before work starts.
- Nearest towns
- Elderslie (1.2 miles), Linwood (1.6 miles), Houston (3.1 miles)
- Distance to Paisley
- about 3.2 miles
- First visit
- Free, no obligation
About an extra bedroom and en-suite extension
This service suits you if you need another bedroom, or want a main bedroom with its own bathroom, without converting the loft or moving. You get a first-floor layout that connects well to your landing, an en-suite designed for plumbing and ventilation, a useful room downstairs, the approvals your nation needs and the build, managed by us and carried out by vetted teams working under S&K.
We cover Johnstone (PA5, PA9 and PA10) and the places around it, including Elderslie (1.2 miles), Linwood (1.6 miles) and Houston.
What it costs in Johnstone
Our guide for Scotland is £1,880–£2,540 per m² including VAT. On a project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that puts an extra bedroom and en-suite extension in Johnstone at roughly £52,500–£71,000 (plus £5,500–£11,000 for the en-suite). These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.
| Spec | Per m² | A 4 m × 3.5 m footprint on two floors (28 m² of new floor space) |
|---|---|---|
| Essential | £1,730–£2,330 per m² | £48,500–£65,500 |
| Standard | £1,880–£2,540 per m² | £52,500–£71,000 |
| Premium | £2,260–£3,050 per m² | £63,000–£85,500 |
Planning and building standards in Johnstone
In Scotland, an extra bedroom on a new first floor makes the extension more than one storey, so Class 1B applies, needing at least 10 m to every boundary. Most plots need a householder application, which costs £371 and is decided within two months. The building warrant then covers the escape window, ventilation and drainage.
Approval in Scotland: Householder planning application: £371. Councils have two months to decide a local planning application.
Building standards: A building warrant from the council's building standards service before work starts, and a completion certificate at the end. Scotland uses its own Technical Handbooks.
Design points for Johnstone homes
Escape window and fire safety
A new first-floor bedroom needs an escape window with a clear opening of at least 0.33 m², at least 450 mm wide and high, and the bottom no more than 1,100 mm above the floor, unless there is a protected route to the stairs. We design the windows to meet this.
Sound and privacy
Bedrooms above a kitchen or family room benefit from an insulated floor to reduce noise. Side-facing upstairs windows usually have to be obscure-glazed, so we place the main bedroom window to the rear and the en-suite window to the side where possible.
How we'd run your project
Free site visit
We visit your home in Johnstone, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings, then consent
We draw the scheme, check it against the rules in Scotland, and take it through the right consent with the council.
Structure and building standards
A structural engineer sizes the foundations and steels, and we get a building warrant before work starts.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.
Questions about extra bedroom and en-suite extensions in Johnstone
Do I need planning permission for an extra bedroom and en-suite extension in Johnstone?
Johnstone is in Scotland. Planning permission is usually needed: Class 1B permitted development only applies if every part of the extension is at least 10 m from all boundaries. A building warrant is needed before work starts.
How long does an extra bedroom and en-suite extension take?
Allow 4 to 8 weeks for survey and design, then the approval period (councils have two months to decide a local planning application), then 4 to 8 weeks of technical design, which can overlap. The build itself usually takes 14 to 20 weeks, longer for large or complex designs.
How much does an extra bedroom and en-suite extension cost in Johnstone?
Our guide for Scotland, which covers Johnstone, is £1,880–£2,540 per m² including VAT. A typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £52,500–£71,000 (plus £5,500–£11,000 for the en-suite). Design and approval fees are extra, and we fix the build price in writing once the design is agreed.
What goes on the ground floor below a new bedroom?
Whatever suits you: a bigger kitchen, a family room, a study, a utility or a downstairs shower room. The ground floor usually costs about the same whatever it is used for, apart from kitchen units and bathroom fittings, which are priced separately.
How big should a new double bedroom be?
There is no legal minimum size for a bedroom in a house you own, so the test is whether it works. A comfortable double needs room for the bed with space to walk round it, wardrobes and a door that opens freely. We draw furniture on the plans so you can judge the space before anything is built.
Nearby
The same service in neighbouring towns:
Other extensions in Johnstone
All two-storey extension services in Johnstone · Extra bedroom and en-suite extensions across Renfrewshire and Inverclyde
Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.