Two-storey extensions for semi-detached houses in Balerno
Adding a two-storey extension for a semi-detached house in Balerno gives you two new rooms stacked on one footprint. Here's how we'd approach it, what it typically costs and the rules that apply in Scotland.
Before you start in Balerno, here's what applies.
- Postcode districts
- EH27
- 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
- Currie (1.5 miles), Colinton (3.6 miles), Penicuik (5.7 miles)
- Distance to Edinburgh
- about 7.3 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 Balerno (EH27) and the places around it, including Currie (1.5 miles), Colinton (3.6 miles) and Penicuik.
What it costs in Balerno
Guide prices for two-storey extensions for semi-detached houses in Scotland are around £1,880–£2,540 per m² of new floor space, including VAT. For a typical project with a 4 m × 3.5 m footprint on two floors (28 m² of new floor space), that's roughly £52,500–£71,000. The fastest way to a firmer number is a free site visit, after which we price the design stage in writing.
| 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 Balerno
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 Balerno homes
Keeping the pair balanced
Semis are designed as matching pairs, and a side extension changes that balance. Setting the side extension back from the front wall and keeping its ridge lower helps the pair still read as a pair, which councils' design guides commonly ask for.
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
Free site visit
We visit your home in Balerno, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Design and approvals
We draw the extension and check it against the rules for Scotland, then apply for planning permission or a certificate of lawfulness, whichever fits.
Technical design
We prepare the building warrant drawings, structural calculations and specification so the build price can be fixed.
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 Balerno
How much does a two-storey extension for a semi-detached house cost in Balerno?
Our guide for Scotland, which covers Balerno, 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.
Which postcodes do you cover around Balerno?
We cover Balerno (EH27) and nearby places including Currie, Colinton and Penicuik, plus the rest of Edinburgh and the Lothians. The first site visit is free.
Do I need planning permission for a two-storey extension for a semi-detached house in Balerno?
Balerno 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.
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
Other towns near Balerno:
Other extensions in Balerno
- Rear
- Side
- Wraparound
- Part two-storey
- Over a garage
- First floor
- Detached
- Kitchen and bedrooms
- Bedroom and en-suite
All two-storey extension services in Balerno · Two-storey extensions for semi-detached houses across Edinburgh and the Lothians
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Balerno.