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 Sunderland?
In Sunderland, a dormer loft conversion typically costs £43,000–£61,000 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Building costs in the North East run about 10% below the UK average, and the figures for Sunderland are adjusted to reflect that. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear dormer with en-suite | £43,000–£61,000 |
| Higher specification | £61,000–£76,000 |
The main things that change the cost:
- Dormer size and roof structure
- Fire safety upgrades to the existing house
- En-suite or bathroom
- Scaffolding and access
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 Sunderland?
Before anything is built in Sunderland, we confirm which approvals apply 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.
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.
We check this for your address before design work starts, so there are no surprises later.
What we handle
From survey to sign-off, the job normally involves:
- Steel beams and new floor joists
- Insulation, plastering, electrics and plumbing
- Measured survey and head-height check
- Dormer structure, roof covering and windows
- Party wall notices for shared walls
- Drawings and structural calculations
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 Sunderland
Across the North East, colliery-era terraces and newer estates sit side by side, so the right project depends on the house type.
Sunderland sits in Tyne and Wear, about 10 miles south-east of Newcastle upon Tyne. We cover the whole of Sunderland, including postcodes SR1 and SR9.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and fixed quote
Drawings, structural calculations and an itemised, fixed price for the agreed specification.
- 03
Approvals in place
We handle planning, building control and neighbour notices before work starts.
- 04
Construction and completion
We build, put right any snags and hand over the building control certificate.
Questions about dormer loft conversions in Sunderland
How long does it take?
Usually 6 to 9 weeks on site.
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.
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 Sunderland?
Planning matters in Sunderland go to the council covering your address, and the work needs building control approval. We prepare and submit the applications for you.
How much does a dormer loft conversion cost in Sunderland?
In Sunderland, a dormer loft conversion typically costs £43,000–£61,000 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
