Extra bedroom and en-suite extensions in Houston

Houston: the key facts for this kind of project.

Postcode districts: PA6, PA11 and PA13
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: Linwood (2.7 miles), Johnstone (3.1 miles), Elderslie (3.5 miles)
Distance to Paisley: about 5.3 miles
First visit: Free, no obligation

About an extra bedroom and en-suite extension

An extra bedroom and en-suite extension is a two-storey extension planned around a new double bedroom with its own shower room on the first floor, with a ground-floor room below. It is one of the most effective ways to add space for a growing family. Nationwide's 2025 research linked adding a double bedroom and bathroom to a three-bed, one-bathroom house with value gains of up to 24%.

Around Houston we also work in Linwood, Johnstone and Elderslie, and across the rest of Renfrewshire and Inverclyde. Postcode districts in and near Houston: PA6, PA11 and PA13.

What it costs in Houston

Using our Scotland rates, an extra bedroom and en-suite extension 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), including VAT. Bigger or more glazed designs cost more per m². Design fees, structural calculations and approval fees are separate and listed on our prices page.

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 Houston

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 Houston 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.

Connecting to the landing

The new bedroom must be reached from the existing landing, usually through a new opening in the outside wall or by taking part of an existing bedroom as a corridor. We look at the stairs and landing first, because a poor connection can waste much of the new space.

How we'd run your project

Visit and first ideas
One of our team visits your house in Houston, checks the walls, roof and drains, and sketches out options with you.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
Technical design
We prepare the building warrant drawings, structural calculations and specification so the build price can be fixed.
On site
One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about extra bedroom and en-suite extensions in Houston

Who handles building standards for a project in Houston?

We handle it as part of the project. What's needed in Scotland: 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. We prepare the drawings and the engineer's calculations, book the inspections and pass you the completion paperwork at the end.

How much does an extra bedroom and en-suite extension cost in Houston?

Our guide for Scotland, which covers Houston, 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.

Do I need planning permission for an extra bedroom and en-suite extension in Houston?

Houston 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 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.

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.

Nearby

Close to Houston? We work across the area, including:

Other extensions in Houston

All two-storey extension services in Houston · 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.