Two-storey extensions for detached houses 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 extension for a detached house involves

This service suits you if you own a detached house and want a substantial amount of extra space, whether a side extension over a drive, a rear extension into the garden or a wraparound. You get a survey of the whole plot, options that compare layouts and costs, the approvals your nation needs, structural design and the build, carried out by vetted teams working under S&K.

Glasgow and Dunbartonshire towns we list: Glasgow (G1), Bearsden (G13), Newton Mearns (G77), Clydebank (G81), Vale of Leven (G82) and Bishopbriggs (G22). Every other address in Glasgow and Dunbartonshire is covered as well.

Guide price in Scotland

Guide prices for two-storey extensions for detached houses in Scotland are around £1,930–£2,580 per m² of new floor space, including VAT. For a typical project with a 3 m × 7 m footprint on two floors (42 m² of new floor space), that's roughly £81,000–£108,500. We'll give you a written design-stage price first, then a fixed build price once the drawings are agreed.

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 detached house on a large plot may be able to use Class 1B permitted development if no part of the two-storey extension is within 10 m of any boundary, it is no higher than the house and is not in a conservation area. Otherwise a householder application costs £371. A building warrant is needed either way.

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

Keeping it subordinate

Large detached houses can take a large extension, but councils still expect it to look secondary to the main house. A lower ridge, a modest set-back at the front and matching materials keep the proportions right, even on a wide plot.

Larger spans and steelwork

Bigger extensions often mean wider openings and longer spans, which need more steel and sometimes a steel frame. The engineer designs these early, because the size of the steel affects ceiling heights, floor depths and the cost.

How we work in Glasgow and Dunbartonshire

Understand the brief
At your home in Glasgow and Dunbartonshire we agree what you need: bedroom count, bathroom, kitchen space, and how much garden you want to keep.
Plans, then approval
Measured survey, design, then the right approval route for your house. We explain each step before we take it.
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 extensions for detached houses in Glasgow and Dunbartonshire: questions

How much does a two-storey extension for a detached house cost in Glasgow and Dunbartonshire?

In Scotland our guide is £1,930–£2,580 per m² including VAT, so about £81,000–£108,500 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 I extend a detached house on both sides?

Sometimes. With planning permission, a council may accept extensions on both sides if the house stays well proportioned and keeps gaps to the boundaries. It is more common to extend on one side and the rear, or with a wraparound. We look at the plot as a whole before suggesting more than one extension.

Is a detached house extension a better investment than moving?

It often costs less than the gap between your house and a larger one nearby, once property tax, legal fees and removal costs are counted, but that depends on your area. Extending also has limits: every street has a ceiling price. We give you build costs so you can compare them with local asking prices.

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 extensions for detached houses