Two-storey extensions for detached houses in the Scottish Borders
If you're in the Scottish Borders and weighing up a two-storey extension for a detached house, start here: guide costs for Scotland, the approvals you'll need and how we work.
The Scottish Borders at a glance
- Nation
- Scotland
- Price region
- Scotland
- Postcode areas
- EH, TD
- Towns covered
- 8 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
A two-storey extension for a detached house is a two-floor addition to the side, rear or both of a house that stands on its own plot. Detached houses often have room on more than one side, so there is more choice of layout and fewer shared-wall issues. The design still needs to respect boundaries, neighbours' windows and the look of the house.
Across Scottish Borders we cover Hawick (TD9), Galashiels (TD1), Peebles (EH45), Kelso (TD3), Selkirk (TD7) and Jedburgh (TD8), plus the smaller places around them.
Guide price in Scotland
Most of the cost of a two-storey extension for a detached house is set by its size and specification. For Scottish Borders and the rest of 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). These are guides, not quotes. Ground conditions, steelwork and access can move the figure either way.
| 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.
Choosing the best side
On a detached house you can often extend on either side or the rear. We look at orientation for daylight, where the stairs and landing are, the distance to each boundary, drains and trees, so the extension goes where it adds the most useful space.
How we work in the Scottish Borders
Look at the house
We start in the Scottish Borders with a free visit: measurements, photos, a look at the loft and drains, and a frank chat about budget.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Scottish Borders.
Structure and building standards
A structural engineer sizes the foundations and steels, and we get a building warrant before work starts.
Build it
The new structure goes up first, then we open into the house, finish inside and get the completion certificate.
Towns we cover in the Scottish Borders
Two-storey extensions for detached houses in the Scottish Borders: questions
How much does a two-storey extension for a detached house cost in the Scottish Borders?
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 the Scottish Borders?
Scottish Borders 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
- Two-storey extensions for detached houses in Edinburgh and the Lothians
- Two-storey extensions for detached houses in Fife
- Two-storey extensions for detached houses in Northumberland
- Two-storey extensions for detached houses in Lanarkshire
All extension services in the Scottish Borders · About two-storey extensions for detached houses
Ready to see what a second storey could do for your home?
Book a free site visit. We'll look at your house, talk through options and explain the approvals you'd need, then price the design stage in writing.