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 Oldham?
In Oldham, a dormer loft conversion typically costs £45,000–£64,000 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 North West, where labour and materials are typically about 6% below average. Design, structural calculations and council fees are extra.
| Size or type | Guide range |
|---|---|
| A typical rear dormer with en-suite | £45,000–£64,000 |
| Higher specification | £64,000–£80,000 |
The main things that change the cost:
- Staircase position
- Dormer size and roof structure
- Scaffolding and access
- Fire safety upgrades to the existing house
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 Oldham?
Before anything is built in Oldham, 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.
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.
At the survey we check your house’s planning history and any restrictions, and tell you which route applies.
What we handle
What we take care of:
- Drawings and structural calculations
- Building control completion certificate
- Dormer structure, roof covering and windows
- Party wall notices for shared walls
- Steel beams and new floor joists
- New staircase and fire-safe escape route
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 Oldham
The North West has many brick terraces and inter-war semis, where kitchen extensions and dormer loft conversions add space without moving.
From OL1 outwards, we take on projects throughout Oldham and the surrounding parts of Greater Manchester.
How it works
- 01
Visit and measured survey
A free visit to understand the project, check access and take measurements.
- 02
Design and pricing
Design options, then a fixed quote based on the chosen drawings and specification.
- 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 Oldham
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.
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 much does a dormer loft conversion cost in Oldham?
In Oldham, a dormer loft conversion typically costs £45,000–£64,000 for a typical rear dormer with en-suite, including VAT at 20% (standard rate). Your fixed price depends on the survey and drawings.
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.
Do you build dormer loft conversions in Oldham?
Yes. We build dormer loft conversions across Oldham, including postcodes OL1 and OL95. Every project starts with a free home visit.