Dumbarton, Glasgow and the Clyde
Two-storey rear extension in Dumbarton
We plan and build two-storey rear extensions for homeowners in Dumbarton. A larger kitchen downstairs and an extra bedroom or bathroom upstairs, under one roof. Start with a free site visit, then a written price once the design is agreed.
We cover Dumbarton (G82) as part of our Glasgow and the Clyde work. In Glasgow and the Clyde we check the neighbours' rear windows first, because the upper floor is where most two-storey schemes win or lose planning.
Book a free site visit
Tell us about the house and we'll call to arrange a free, no-obligation visit.
How much does a two-storey rear extension cost in Dumbarton?
A two-storey rear extension in Dumbarton is priced at £1,710–£2,560 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 × 5 m footprint, two floors (30 m²) | £51,500–£77,000 |
| 4 m × 6 m footprint, two floors (48 m²) | £82,000–£123,000 |
Ground conditions, glazing, the roof and how far the house is opened up move the final figure within the range.
Do you need planning permission for a two-storey rear extension in Dumbarton?
Here is how the rules in Scotland apply to a two-storey rear extension in Dumbarton.
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.
Classes 1A and 1B do not apply in conservation areas, and listed buildings need listed building consent. We check your house's planning history and any conservation area before drawing, so the route is clear before you spend on plans.
What are homes in Dumbarton like to extend?
Dumbarton 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 a two-storey rear extension in Dumbarton comes together
Look round and measure
A free visit to see the back of the house, measure it, check the drains and boundaries and hear what you need.
Options and costs
We draw layout options and price each one, so the budget shapes the design rather than surprising you later.
Approvals
Permitted development check or planning application, then building warrant drawings and structural calculations, plus a written agreement with neighbours for any shared-wall work.
Written price, then build
Once the design and approvals are in place, you get a fixed written price and programme, and we build through to sign-off.
Two-storey rear extensions near Dumbarton
Close by, we work in Vale of Leven, about 1.9 miles away, and Port Glasgow, about 4.6 miles away.
- Two-storey rear extension in Vale of Leven
- Two-storey rear extension in Port Glasgow
- Two-storey rear extension in Erskine
- Two-storey rear extension in Clydebank
- Two-storey rear extension in Greenock
Other work in Dumbarton:
FAQ
Two-storey rear extension questions in Dumbarton
Can I get a price without a visit?
Our online guide-price tool gives a range in a couple of minutes. A written price needs a survey.
What postcode areas do you cover around Dumbarton?
Including G82, and the surrounding Glasgow and the Clyde area.
Can it be built on a terraced house?
Sometimes, but the upper floor is harder to get through planning on a terrace because of the effect on neighbours. A single-storey extension with a loft conversion is often an easier route.
Will I need a structural engineer?
Yes for the beam over the new opening and usually the foundations; we arrange them and their calculations go to building control.
Do I need a party wall agreement?
Scotland has no Party Wall Act; we agree access and protection with your neighbour in writing instead.
Do I need planning permission for a rear extension in Dumbarton?
Many single-storey rear extensions are permitted development under Class 1A, but not in conservation areas; you always need a building warrant before work starts.