Scottish Borders
Rear extensions for semi-detached houses in the Scottish Borders
Single or two-storey extensions for semi-detached houses, with side access and one party wall. Rear extensions in the Scottish Borders: we cover 5 towns including Hawick, Galashiels and Peebles, with design, approvals and the build under one contract.

In Hawick we measure the attached neighbour's extension at the survey, because it often sets the sensible depth for yours. Post-war semis and terraces are common around the Scottish Borders, and many have room for a single-storey rear extension within Class 1A limits.
How much does a semi-detached rear extension cost in the Scottish Borders?
In the Scottish Borders, our guide for a semi-detached rear extension is £1,800–£2,940 per square metre including VAT for a standard specification. Prices in Scotland sit a little below our West Midlands baseline; building warrant fees and drawings are budgeted separately.
| Size | Guide price inc VAT |
|---|---|
| 3 m wide × 4 m deep (12 m²) | £21,500–£35,500 |
| 4 m wide × 5 m deep (20 m²) | £36,000–£59,000 |
| 4 m wide × 6 m deep (24 m²) | £43,500–£70,500 |
These are guide ranges; the written quote after the survey is the figure that counts.
Do you need planning permission in the Scottish Borders?
In Scotland a single-storey rear extension can be permitted development under Class 1A: eaves no higher than 3 metres and an overall height of 4 metres, and where any part is within 1 metre of a boundary it can project no more than 3 metres on a terraced house or 4 metres on other houses. The rights do not apply in conservation areas, and a building warrant is still needed before work starts.
In Scotland an extension of more than one storey is only permitted development (Class 1B) if no part is within 10 metres of any boundary and it is no higher than the existing house, so almost every two-storey rear extension needs planning permission and a building warrant.
Scotland has no larger-extension prior approval route; extensions beyond permitted development need a planning application.
Classes 1A and 1B do not apply in conservation areas, and listed buildings need listed building consent.
Where in the Scottish Borders do we work?
FAQ
Questions people ask
Can I match pebbledash or render?
Yes. Many semis are refinished with new render across the whole back elevation so old and new match.
Single or two-storey on a semi?
Two-storey if you need bedrooms, single-storey if you need a bigger kitchen. Planning risk is lower for single-storey.
What if my neighbour has already extended?
That can make a matching depth easier to justify. We measure theirs at the survey.
Do you cover all of the Scottish Borders?
We cover 5 towns and districts in the Scottish Borders, including Hawick, Galashiels and Peebles.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.