Clarkston · Glasgow and Dunbartonshire

Two-storey extensions for semi-detached houses in Clarkston

A two-storey extension for a semi-detached house is one of the most space-efficient ways to add bedrooms and living space to a house in Clarkston, because the new floors share one set of foundations and one roof.

Before you start in Clarkston, here's what applies.

Postcode districts
G76
County / area
Glasgow and Dunbartonshire, Scotland
Price region
Scotland
Guide price
£52,500–£71,000 (£1,880–£2,540 per m²)
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
Giffnock (1.4 miles), Newton Mearns (2.4 miles), Rutherglen (3.8 miles)
Distance to Glasgow
about 5.5 miles
First visit
Free, no obligation

About a two-storey extension for a semi-detached house

A two-storey extension for a semi-detached house is a two-floor addition to the rear, the open side, or both, designed around the attached neighbour on one side. The rear is often the simplest option and can sometimes be permitted development, while a side extension uses the gap on the detached side. Both need care with the shared party wall and the neighbour's light.

We cover postcode district G76 in and around Clarkston, along with neighbouring Giffnock, Newton Mearns and Rutherglen.

What it costs in Clarkston

Using our Scotland rates, a two-storey extension for a semi-detached house with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space) comes to about £52,500–£71,000, including VAT. Bigger or more glazed designs cost more per m². These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.

SpecPer m²A 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 Clarkston

In Scotland, Class 1B permitted development needs a two-storey extension to be at least 10 m from every boundary, which a semi-detached house cannot meet on the attached side. In practice a two-storey extension to a semi needs a householder application, which costs £371 and is decided within two months, followed by a building warrant.

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 Clarkston homes

Rear, side or both

On a semi, a rear extension sits against the attached neighbour, while a side extension faces the detached neighbour and the street. We compare the space, cost and approval route for each, and for a wraparound, before you commit to one design.

The attached neighbour's light

A two-storey rear extension next to the party wall can take light from the neighbour's rear windows. Councils often use a 45-degree test, so the first floor may need to be shorter than the ground floor or set in from the shared boundary.

How we'd run your project

  1. Visit and first ideas

    One of our team visits your house in Clarkston, checks the walls, roof and drains, and sketches out options with you.

  2. Drawings, then consent

    We draw the scheme, check it against the rules in Scotland, and take it through the right consent with the council.

  3. Engineer it

    Foundations sized for two floors, steels for any openings, and a building warrant, all before anyone starts on site.

  4. On site

    One project lead runs the job, keeps you updated and arranges inspections at each stage until completion.

Questions about two-storey extensions for semi-detached houses in Clarkston

Do I need planning permission for a two-storey extension for a semi-detached house in Clarkston?

Clarkston 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 a two-storey extension for a semi-detached house 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.

Who handles building standards for a project in Clarkston?

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.

What if my neighbour has already extended?

That often helps. An existing extension next door can reduce the effect of yours on their light, and may show what the council accepts on your street. It can also mean building alongside their wall, so we check its position, foundations and any windows facing your plot at the survey.

Will a side extension make my semi look like a terrace?

It can if it fills the whole gap to the boundary at first floor and the neighbour does the same. Many councils ask for a first-floor gap to the side boundary or a set-back for this reason. We design the extension to keep the semi reading as one of a pair.

Nearby

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

Other extensions in Clarkston

All two-storey extension services in Clarkston · Two-storey extensions for semi-detached houses across Glasgow and Dunbartonshire

Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Clarkston.

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