Two-storey extensions for semi-detached houses in Bathgate

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

Postcode districts: EH48
County / area: Edinburgh and the Lothians, 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: Armadale (2.5 miles), Whitburn (2.9 miles), Livingston (4.7 miles)
Distance to Edinburgh: about 17.7 miles
First visit: Free, no obligation

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

This service suits you if you own a semi-detached house and want to add bedrooms and living space without moving. On a semi, the main questions are which side to build on and how to treat the attached neighbour. You get a survey, design options, the approvals your nation needs and the build, carried out by vetted teams working under S&K.

We cover Bathgate (EH48) and the places around it, including Armadale (2.5 miles), Whitburn (2.9 miles) and Livingston.

What it costs in Bathgate

Expect a two-storey extension for a semi-detached house in Bathgate to land somewhere around £52,500–£71,000 for a 4 m × 3.5 m footprint on two floors (28 m² of new floor space). Our Scotland guide rate is £1,880–£2,540 per m², including VAT. Kitchens, bathroom fittings and flooring are priced separately so you can compare like with like.

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 Bathgate

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 Bathgate homes

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.

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.

How we'd run your project

Measure and listen
A visit to Bathgate to understand how you live in the house now and what the extra rooms need to do, plus a first look at the structure.
Choose the approval route
Some designs fit permitted development, most need a householder application. We decide which applies in Scotland before drawing in detail.
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.
Build and hand over
We manage the build from groundworks to decoration-ready finish and hand over with the completion paperwork.

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

Who handles building standards for a project in Bathgate?

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.

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

Bathgate 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 much does a two-storey extension for a semi-detached house cost in Bathgate?

Our guide for Scotland, which covers Bathgate, 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. Design and approval fees are extra, and we fix the build price in writing once the design is agreed.

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.

Does a two-storey extension add value to a semi-detached house?

It usually adds value, but the gain is never certain. Nationwide's 2025 research found that 10% more floor area was linked to about 5% higher value, and that adding a double bedroom and bathroom to a three-bed, one-bathroom house could add up to 24%. Every street has a ceiling price, so check local sales first.

Nearby

We also cover places near Bathgate, including:

Other extensions in Bathgate

All two-storey extension services in Bathgate · Two-storey extensions for semi-detached houses across Edinburgh and the Lothians

Send us your postcode and a few details. We'll get back to you to arrange a visit and talk through your options.