dormers
Extensions of living space which protrude from a sloping roof below the peak or ridge line.
A dormer is an architectural feature which projects from a sloping roof in order to accommodate extended living space or additional headroom in the room(s) below it. Dormers add further planes and angles to a roof surface, and may take a variety of forms; they may be gabled, flat-topped, hipped, or slope-roofed. A dormer with a downward-sloping roof is called a 'shed dormer'. Most dormers have a window in the vertical plane.
Dormers are always lower than the roof itself from which they protrude. If the uppermost point of a dormer-like structure extended up to the peak or ridge line of the roof; it would become a cross-gable or other extension of the roof.
A building may list dormers as a feature even if it has only one dormer. The existence of dormers does not affect or change the roof form of a structure.