Dumbarton timber frame extensions, designed and built
From the first sketch to final sign-off, we plan and build timber frame extensions in Dumbarton and the surrounding Dunbartonshire area.
- Guide price in DumbartonFrom £20,500 inc VAT
- PlanningScottish householder rules; building warrant needed
- Build time8–14 weeks on site
- Postcode districtsG82

Planning and approvals in Dumbarton
In Scotland, householder permitted development rules (Class 1A for single-storey ground-floor extensions and Class 1B for extensions of more than one storey) allow some smaller extensions without a planning application, within limits on depth, height and distance from the boundary. Conservation areas and listed buildings are more restricted. Separately, almost every extension needs a building warrant from the council before work starts.
Homes in conservation areas, national scenic areas and listed buildings have tighter rules, so we always check the property's status and planning history before design starts.
Building close to a public sewer needs the agreement of Scottish Water, which we check during design.
Scotland has no Party Wall Act. Where work affects a shared wall or a neighbour's land, we agree access, protection and making good with your neighbour in writing before work starts.
Applications are decided by your council as planning authority.
Local to Dumbarton
Site visits are available across Dumbarton (G82). We also work in nearby Vale of Leven (2 miles), Clydebank (7 miles), Bearsden (9 miles), Bishopbriggs (14 miles).
For homes towards Renfrewshire and Inverclyde, Erskine is around 6 miles away. Scotland's housing includes sandstone villas, terraces and tenements in the cities and plenty of post-war and modern houses and bungalows elsewhere. A building warrant is needed before work starts.
What we take care of
- Foundations, often lighter than masonry
- Cladding, render or brick slip finish
- Breathable wall build-up with insulation
- Fire and acoustic details where needed
- Frame design and structural calculations
Guide prices for Dumbarton
Prices below are for Dumbarton, using the Scotland factor of ×0.98. They are guide ranges including VAT for the build only, not a quote.
Typical rates in Dumbarton: £1,720 to £3,330 per m² including VAT, depending on specification.
| Size | Essential | Standard | Premium |
|---|---|---|---|
| 3 m × 4 m 12 m² | £20,500 – £25,000 | £24,000 – £31,500 | £30,500 – £40,000 |
| 4 m × 5 m 20 m² | £34,000 – £41,500 | £40,000 – £52,000 | £50,500 – £67,000 |
| 5 m × 6 m 30 m² | £51,000 – £62,000 | £60,000 – £78,000 | £76,000 – £100,000 |
Try the guide-price tool to see a range for your own size and finish.
How the project works
Site visits are free and there is no obligation. Where drawings are needed, the design stage is priced in writing before it starts.
Free site visit
We visit your Dumbarton home, measure up, talk through what you want and check the planning position.
Design and approvals
Drawings are prepared and agreed with you, then submitted for the right planning route and building regulations approval.
Fixed written price
You receive a written, itemised price and programme. Nothing starts until you are happy with it.
Build and sign-off
The build is managed from start to finish, inspected at each stage and signed off on completion.
Timber frame extension questions answered
Can I see a price before committing to anything?
Yes. The guide prices on this page are adjusted for Dumbarton, and the guide-price tool gives a range for your own size. After the survey you get a written price before anything is agreed.
Do you cover all of Dumbarton?
Yes. We cover Dumbarton and the surrounding parts of Dunbartonshire. Site visits are free and there is no obligation.
Do I need building regulations approval in Dumbarton?
Yes. Almost every extension needs it, whatever the planning route. In Scotland that means a building warrant before work starts.
Does a timber frame extension need planning permission?
The same planning rules apply as for any extension. If the cladding looks different from the house, permitted development’s matching-materials condition may mean an application is needed.
Is timber frame cheaper than brick?
It is similar overall. The frame can save time on site, but the cladding choice has a big effect on cost. Our guide range is about £1,720 to £3,330 per m² including VAT.
Book a free site visit in Dumbarton
We will measure up, check the planning position and give you honest guide figures.
- Free, no-obligation site visit
- Planning route checked before you spend on drawings
- Written price once the design is agreed
- Building control sign-off at the end
Prefer to talk? Call 0800 088 6341 or .
Book a free site visit
Tell us a little about the project and we will arrange a time.