Forth Valley
Rear extensions for semi-detached houses in Forth Valley
Single or two-storey extensions for semi-detached houses, with side access and one party wall. Across Forth Valley we handle the whole rear extension: survey, drawings, the planning route, building control and the build. Towns we cover here include Stirling, Falkirk and Alloa.
Where a Stirling semi already has a small lean-to at the back, we usually replace it rather than extend it. Post-war semis and terraces are common around Forth Valley, and many have room for a single-storey rear extension within Class 1A limits.
How much does a semi-detached rear extension cost in Forth Valley?
Guide prices for a semi-detached rear extension in Forth Valley start from our Scotland rate of £1,800–£2,940 per square metre, including VAT. 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 |
We put a fixed price in writing once the design is agreed, and explain any provisional sums such as foundations.
Do you need planning permission in Forth Valley?
Scottish householder permitted development (Class 1A) covers many single-storey rear extensions, with a 3 metre eaves limit, a 4 metre height limit and, within 1 metre of a boundary, a depth limit of 3 metres for terraced houses or 4 metres for others. Conservation areas are excluded, and you need a building warrant whatever the planning position.
Scottish Class 1B rights for extensions of more than one storey need a 10 metre gap to every boundary, which few gardens have. Expect a planning application as well as a building warrant for a double-storey rear extension.
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 Forth Valley 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 Forth Valley?
We cover 6 towns and districts in Forth Valley, including Stirling, Falkirk and Alloa.
Who builds the extension?
Vetted building teams working under contract to us; your contract is with S&K Property Investments and Improvement Ltd.