What is a dormer loft conversion?
A dormer loft conversion adds a box-shaped structure to the rear roof slope, creating vertical walls and full headroom across most of the new room. It is the most common loft conversion in the UK because it works on terraced, semi-detached and detached houses.
How much does a dormer loft conversion cost in Dunbartonshire?
In Dunbartonshire, a dormer loft conversion typically costs £46,500–£66,000 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Prices in Scotland sit near the national average for this kind of work, and the range for Dunbartonshire reflects that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear dormer with en-suite | £46,500–£66,000 |
| Higher specification | £66,000–£82,500 |
What moves the price most:
- Staircase position
- Fire safety upgrades to the existing house
- Built-in storage and finishes
- Dormer size and roof structure
For a figure based on your own measurements, try the guide price tool, then book a free home visit for a fixed quote.
Do you need planning permission for a dormer loft conversion in Dunbartonshire?
Whether you need planning permission depends on your house and its location in Scotland. In Scotland a dormer is permitted development (Class 1D) only on a roof slope that does not face a road, at least 10 metres from the boundary it faces, no wider than half the roof at the eaves, set at least 0.3 metres from the roof edges and with no increase in ridge height. It is not permitted development in a conservation area, and a building warrant is needed for a loft conversion.
In Scotland a building warrant is needed before work starts on most extensions, loft conversions and conversions. It is issued by the council’s building standards service. When the work is finished, a completion certificate is submitted and accepted by the council after inspection.
We check this for your address before design work starts, so there are no surprises later.
What we handle
On a typical dormer loft conversion we handle:
- Steel beams and new floor joists
- Insulation, plastering, electrics and plumbing
- New staircase and fire-safe escape route
- Building control completion certificate
- Dormer structure, roof covering and windows
- Drawings and structural calculations
How long does it take?
Build time is typically 6 to 9 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Dunbartonshire
In Scotland, bungalows and one-and-a-half-storey homes are common, so dormer conversions are a popular way to add bedrooms.
Towns we cover in Dunbartonshire include Bearsden, Clydebank, Dumbarton and Kirkintilloch.
How it works
- 01
Free visit
We look at the property, talk through what you want and measure up. There is no charge and no obligation.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Permissions sorted
Applications, building control and neighbour arrangements, all before the start date.
- 04
Build and handover
Work follows the agreed programme, with inspections along the way and a completion certificate at the end.
Questions about dormer loft conversions in Dunbartonshire
How much head height do I need?
Ideally at least 2.2 metres from the top of the ceiling joists to the underside of the ridge. Less can still work with a dormer, but we check this at the survey.
Do I need planning permission for a dormer loft conversion in Dunbartonshire?
In Scotland a dormer is permitted development (Class 1D) only on a roof slope that does not face a road, at least 10 metres from the boundary it faces, no wider than half the roof at the eaves, set at least 0.3 metres from the roof edges and with no increase in ridge height. It is not permitted development in a conservation area, and a building warrant is needed for a loft conversion.
What fire safety is required?
Building regulations require a safe escape route. Converting a two-storey house to three storeys usually means a protected stairway with fire doors to habitable rooms and mains-wired smoke alarms.
Do you build dormer loft conversions in Dunbartonshire?
Yes. We build dormer loft conversions across Dunbartonshire, including postcodes G13, G22, G23, G3 and G31. Every project starts with a free home visit.
How long does it take?
Usually 6 to 9 weeks on site.
How much does a dormer loft conversion cost in Dunbartonshire?
In Dunbartonshire, a dormer loft conversion typically costs £46,500–£66,000 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.