Two-storey extensions for semi-detached houses in Glenrothes
Adding a two-storey extension for a semi-detached house in Glenrothes 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 Glenrothes, here's what applies.
- Postcode districts
- KY6 and KY7
- County / area
- Fife, 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
- Kirkcaldy (5.4 miles), Methil (5.9 miles), Ballingry (6.3 miles)
- Distance to Dunfermline
- about 13.9 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.
Around Glenrothes we also work in Kirkcaldy, Methil and Ballingry, and across the rest of Fife. Postcode districts in and near Glenrothes: KY6 and KY7.
What it costs in Glenrothes
Expect a two-storey extension for a semi-detached house in Glenrothes 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. Design fees, structural calculations and approval fees are separate and listed on our prices page.
| 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 Glenrothes
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 Glenrothes 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
Visit and first ideas
One of our team visits your house in Glenrothes, checks the walls, roof and drains, and sketches out options with you.
Drawings, then consent
We draw the scheme, check it against the rules in Scotland, and take it through the right consent with the council.
Engineer it
Foundations sized for two floors, steels for any openings, and a building warrant, all before anyone starts on site.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.
Questions about two-storey extensions for semi-detached houses in Glenrothes
Which postcodes do you cover around Glenrothes?
We cover Glenrothes (KY6 and KY7) and nearby places including Kirkcaldy, Methil and Ballingry, plus the rest of Fife. The first site visit is free.
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.
How much does a two-storey extension for a semi-detached house cost in Glenrothes?
Our guide for Scotland, which covers Glenrothes, 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.
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.
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
Nearby towns we cover for two-storey extensions for semi-detached houses:
Other extensions in Glenrothes
- 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 Glenrothes · Two-storey extensions for semi-detached houses across Fife
Ready to talk it through? Call us or send the form and we'll arrange a visit to your home in Glenrothes.