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 Coventry?
In Coventry, 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 the West Midlands are close to the UK average, so the figures for Coventry 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 |
The main things that change the cost:
- Dormer size and roof structure
- Scaffolding and access
- En-suite or bathroom
- Fire safety upgrades to the existing house
Your exact price depends on the survey and drawings. The guide price tool gives a quick range in the meantime.
Do you need planning permission for a dormer loft conversion in Coventry?
Whether you need planning permission depends on your house and its location in England. In England a rear dormer is often permitted development if the extra roof volume is no more than 40 cubic metres on a terraced house or 50 on other houses, it does not face the road, sits no higher than the ridge and is set back from the eaves, with matching materials and obscure-glazed side windows. Balconies, front dormers and work in conservation areas need planning permission.
Where work involves a shared wall, building on the boundary, or digging foundations within 3 metres of a neighbour’s building and deeper than its foundations (or within 6 metres for deeper work), the Party Wall etc. Act 1996 applies and notices must be served before work starts.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
From survey to sign-off, the job normally involves:
- Dormer structure, roof covering and windows
- Drawings and structural calculations
- New staircase and fire-safe escape route
- Steel beams and new floor joists
- Insulation, plastering, electrics and plumbing
- Measured survey and head-height check
How long does it take?
The build itself usually takes 6 to 9 weeks on site. Design and approvals come first and typically take 6 to 12 weeks, depending on the approval route.
Building in Coventry
Across the West Midlands, inter-war and post-war semis make up much of the housing, giving good scope for two-storey side extensions and hip-to-gable lofts.
We work across Coventry and neighbouring areas such as Kenilworth, Bedworth and Nuneaton. Postcodes we cover in Coventry include CV1.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 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 Coventry
Who approves a dormer loft conversion in Coventry?
Planning matters in Coventry go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How long does it take?
Usually 6 to 9 weeks on site.
How much does a dormer loft conversion cost in Coventry?
In Coventry, 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.
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.
Will I need to move out?
No. Most of the work is done from scaffolding and the roof. The new staircase is formed near the end, which causes a few days of disruption.
