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 Ely?
In Ely, a dormer loft conversion typically costs £51,000–£72,000 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). We start from a UK-wide guide and adjust it for the East of England, where labour and materials are typically about 6% above average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear dormer with en-suite | £51,000–£72,000 |
| Higher specification | £72,000–£90,000 |
The biggest cost drivers are:
- Scaffolding and access
- Staircase position
- Fire safety upgrades to the existing house
- En-suite or bathroom
Use the guide price tool to see how size and specification change the figure, then ask for a written, itemised quote.
Do you need planning permission for a dormer loft conversion in Ely?
Approvals for a dormer loft conversion in Ely follow the rules for 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.
Building regulations approval comes from the council’s building control service or a registered building control approver. The work is inspected at key stages, such as foundations, drainage and insulation, and a completion certificate is issued at the end.
If the answer is not clear-cut, we can apply for formal confirmation before you commit to the build.
What we handle
Handled as part of most dormer loft conversions:
- Insulation, plastering, electrics and plumbing
- Measured survey and head-height check
- Party wall notices for shared walls
- Dormer structure, roof covering and windows
- Drawings and structural calculations
- New staircase and fire-safe escape route
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 Ely
Across the East of England, 1930s and post-war semis, newer estates and rural cottages all feature, each with different extension and loft options.
We work across Ely and neighbouring areas such as Newmarket, March and Cambridge. Postcodes we cover in Ely include CB7.
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
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 Ely
Does a dormer loft conversion need planning permission?
A rear dormer is often permitted development in England, provided the extra roof volume is within 40 cubic metres on a terraced house or 50 on a semi-detached or detached house, and it does not face the road. Front dormers and houses in conservation areas usually need an application.
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.
Do I need a party wall agreement?
In England and Wales, if the conversion cuts into or builds on a shared wall, notices must be served under the Party Wall etc. Act 1996.
How long does a dormer loft conversion take in Ely?
Typically 6 to 9 weeks on site. Design and approvals beforehand usually take 6 to 12 weeks.
How much does a dormer loft conversion cost in Ely?
In Ely, a dormer loft conversion typically costs £51,000–£72,000 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.