A dormer is a box-shaped structure built out from the rear slope of your roof. It creates vertical walls and a flat ceiling, turning a cramped loft into a full-height room with space for a double bed, wardrobes and usually an en-suite.
Our recent Didsbury project is a good example: a rear dormer that transformed an unused attic into a bright master bedroom with its own shower room. Dormers are part of our wider loft conversion service.
Rear, L-shaped and full-width dormers
A rear dormer sits on the back roof slope and suits most houses. On Victorian terraces with a rear outrigger, an L-shaped dormer runs over both the main roof and the back extension roof, often creating two bedrooms or a bedroom and bathroom. A full-width dormer spans the whole rear slope for maximum space.
Dormers and permitted development
Rear dormers are often permitted development, provided the extra volume stays within 40 cubic metres (terraced) or 50 cubic metres (semi-detached and detached), materials look similar to the existing house, the dormer is set back from the eaves where practical and side-facing windows are obscure-glazed. Front dormers and homes in conservation areas need planning permission. Full details are in our loft conversion planning guide.