L-Shaped Dormer
The Classic London Choice
The most popular loft conversion for Victorian and Edwardian terraces. A box dormer extending from the rear roof to create spacious, light-filled rooms.
Full Height Across the Rear
An L-shaped (or box) dormer extends out from the sloped rear roof, creating a flat-roofed box with full-height walls. It's called "L-shaped" when it wraps around the rear outrigger common in Victorian terraces.
The result is a dramatic increase in usable space—typically enough for a master bedroom with en-suite, or two separate rooms. Windows across the rear flood the space with light.
- Usually Permitted Development
- 25-35sqm new floor space
- Tailored to your roof shape and layout
- 8-12 weeks build time
Why Choose a Dormer Loft?
Full Head Height
Vertical walls across the rear mean no stooping or wasted eaves space.
Natural Light
Large rear windows flood your new rooms with daylight.
No Planning (Usually)
Most rear dormers fall under Permitted Development rights.
Great Value
Excellent space-to-cost ratio compared to other conversion types.
Dormer Loft Questions
An L-shaped dormer (also called a box dormer) is a flat-roofed extension that projects from the rear slope of your roof. For Victorian terraces with a rear outrigger, the dormer wraps around in an L-shape to maximise space over both sections of the rear roof.
We scope dormer loft conversions after reviewing the roof structure, the rooms you want to create, access requirements, and the specification for finishes and bathroom fit-out where needed.
Rear dormers usually fall under Permitted Development and don't need planning. However, if your home is in a conservation area, or you want a front-facing dormer, planning permission may be required. We assess this during our free survey.
Book Your Free Survey
We'll assess your roof, confirm planning status, and provide a fixed-price quote within 48 hours.
