Forth Valley
Flat-roof rear extensions in Forth Valley
Warm flat roofs with lanterns, parapets and long-life membranes. Rear extensions in Forth Valley: we cover 6 towns including Stirling, Falkirk and Alloa, with design, approvals and the build under one contract.
Flat roofs are the usual choice for rear extensions because they stay below first-floor windows and take a lantern neatly. Forth Valley has sandstone villas and terraces, post-war semis and four-in-a-block flats. Flats need planning permission for an extension, and every project needs a building warrant before work starts.
How much does a flat-roof rear extension cost in Forth Valley?
A flat-roof rear extension in Forth Valley is priced at £1,800–£2,940 per square metre including VAT as a guide, before kitchen fit-out and fees. 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 |
Your written price follows a measured survey and an agreed design, so it reflects your house, not an average.
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.
Insulation and glazing follow Section 6 of the Scottish Technical Handbook; the building warrant drawings show how the extension meets it.
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
How long does a flat roof last?
A well-built single-ply or GRP warm roof typically lasts 25 years or more.
Is a flat roof really flat?
No; it is built to falls so water drains to outlets or gutters.
Can I walk on it?
Not as a balcony without planning permission and a guarding design; it can be accessed for maintenance.
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.