Extra bedroom and en-suite extensions in Glasgow and Dunbartonshire

Glasgow and Dunbartonshire at a glance

Nation: Scotland
Price region: Scotland
Postcode areas: G
Towns covered: 19 listed below, plus surrounding villages
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.
Site visits: Free, no obligation

What an extra bedroom and en-suite extension involves

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%.

The main places we list in Glasgow and Dunbartonshire are Glasgow (G1), Bearsden (G13), Newton Mearns (G77), Clydebank (G81), Vale of Leven (G82) and Bishopbriggs (G22). We cover the villages in between too.

Guide price in Scotland

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	Typical project
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

Rules in Scotland

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.

There is no Party Wall Act in Scotland. Shared walls and boundaries are governed by title deeds and common law, so we speak to neighbours early and record the condition of shared structures.

Getting the design right

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 work in Glasgow and Dunbartonshire

Look at the house
We start in Glasgow and Dunbartonshire with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Scotland before drawing in detail.
Detail and price
Construction drawings, engineer's calculations and building warrant approval, then a written fixed price for the build.
Build and sign-off
Vetted teams working under S&K build the extension, and we arrange the completion certificate at the end.

Towns we cover in Glasgow and Dunbartonshire

Extra bedroom and en-suite extensions in Glasgow and Dunbartonshire: questions

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

In Scotland our guide is £1,880–£2,540 per m² including VAT, so about £52,500–£71,000 (plus £5,500–£11,000 for the en-suite) for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.

Does an extra bedroom add value to my house?

It usually does, though not always by the full cost. Nationwide's 2025 research found that adding a double bedroom to a two-bed house was linked to about 13% higher value, and a double bedroom and bathroom on a three-bed, one-bathroom house up to 24%. Local ceiling prices still apply.

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.

Will I need planning permission in Glasgow and Dunbartonshire?

Glasgow and Dunbartonshire 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.

Neighbouring areas

All extension services in Glasgow and Dunbartonshire · About extra bedroom and en-suite extensions