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 Bathgate?
In Bathgate, a dormer loft conversion typically costs £46,500–£66,000 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Building costs in Scotland are close to the UK average, so the figures for Bathgate are close to our national guide. 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:
- En-suite or bathroom
- Scaffolding and access
- Built-in storage and finishes
- Fire safety upgrades to the existing house
A guide range is only a starting point: the guide price tool gives an instant figure for your size, and a free survey turns it into a fixed quote.
Do you need planning permission for a dormer loft conversion in Bathgate?
Here is how the rules work for a dormer loft conversion 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
The work we manage on a dormer loft conversion:
- Dormer structure, roof covering and windows
- Building control completion certificate
- New staircase and fire-safe escape route
- Insulation, plastering, electrics and plumbing
- Steel beams and new floor joists
- Measured survey and head-height check
How long does it take?
The build itself usually takes 6 to 9 weeks on site. Allow time beforehand for drawings and approvals, usually 6 to 12 weeks.
Building in Bathgate
Scotland’s housing ranges from sandstone tenements and villas to post-war and modern estates, and the building warrant system shapes how projects are planned.
From EH48 outwards, we take on projects throughout Bathgate and the surrounding parts of the Lothians.
How it works
- 01
Survey and brief
We visit, discuss your ideas and budget, and survey the property or site at no cost.
- 02
Drawings and written quote
We prepare the design and give you a written, itemised quote with inclusions and exclusions.
- 03
Approvals
Planning or permitted development confirmation, building regulations and any party wall matters.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about dormer loft conversions in Bathgate
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.
How long does it take?
Usually 6 to 9 weeks on site.
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.
Who approves a dormer loft conversion in Bathgate?
Planning matters in Bathgate go to the council covering your address, and the work needs a building warrant. We prepare and submit the applications for you.
Do I need planning permission for a dormer loft conversion in Bathgate?
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.
How much does a dormer loft conversion cost in Bathgate?
In Bathgate, 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.
