Two-storey annexe 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 a two-storey annexe extension involves

This service suits you if a parent, grown-up child or carer is moving in and you want them to have their own space while staying connected to the house. You get a layout that can be self-contained or shared, the approvals your nation needs with the annexe use made clear, accessible design where needed and the build, carried out by vetted teams working under S&K.

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

In Scotland, which includes Glasgow and Dunbartonshire, we'd expect a two-storey annexe extension to cost around £81,000–£108,500 (plus kitchenette and shower room fittings, priced to your choice) for a 3 m × 7 m footprint on two floors (42 m² of new floor space), or £1,930–£2,580 per m² including VAT. Professional fees for drawings and the structural engineer are listed separately on our prices page.

Spec	Per m²	Typical project
Essential	£1,770–£2,380 per m²	£74,500–£100,000
Standard	£1,930–£2,580 per m²	£81,000–£108,500
Premium	£2,310–£3,100 per m²	£97,000–£130,500

Rules in Scotland

In Scotland, a two-storey annexe extension needs to be at least 10 m from every boundary to be permitted development under Class 1B, so most need a householder application (£371, decided within two months). The building warrant covers fire safety and escape for the self-contained layout.

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

Fire separation and escape

A kitchenette in an annexe and a bedroom above need safe escape and suitable separation from the main house. Building standards checks the escape windows, smoke alarms and the door between the two parts.

Annexe, not a separate house

To stay an annexe, the space should be used by members of the household and stay linked to the main house, usually with an internal door and shared address, garden and services. Designing it as a fully separate home can mean the council treats it as a new dwelling.

How we work in Glasgow and Dunbartonshire

Start at your house
We come to your home in Glasgow and Dunbartonshire, measure up, check the ground floor walls and roof structure, and note anything near the boundaries.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Glasgow and Dunbartonshire.
Price it properly
Once the engineer's calculations are in, we fix the build price in writing, with a clear list of what's included.
Finish and certify
Second fix, plastering and making good, then the council's final building standards inspection and the completion paperwork.

Towns we cover in Glasgow and Dunbartonshire

Two-storey annexe extensions in Glasgow and Dunbartonshire: questions

How much does a two-storey annexe extension cost in Glasgow and Dunbartonshire?

In Scotland our guide is £1,930–£2,580 per m² including VAT, so about £81,000–£108,500 (plus kitchenette and shower room fittings, priced to your choice) for a 3 m × 7 m footprint on two floors (42 m² of new floor space). Essential and Premium specs move that by roughly 8% down or 20% up.

Can an annexe have its own front door?

It can, but a separate front door, kitchen and address together make it look more like a separate home, which can change how the council treats it for planning. Many annexes have their own door to the garden or side and an internal door to the main house. We explain how each choice is likely to be viewed before the design is fixed.

Can I rent out an annexe later?

Not always. Many annexe permissions include a condition that it is only used by members of the household, so renting it out may need a fresh planning application. If you think you might want to let it, tell us at the start so we can explain the options.

Can an annexe be designed for someone with limited mobility?

Yes. We can plan a ground-floor bedroom space, a level-access shower, wider doorways, lever handles and space for a stairlift later. These features are much cheaper to build in at the start than to add afterwards, and they keep the annexe useful as needs change.

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 two-storey annexe extensions