A dormer is a roofed structure, often containing a window, that projects vertically beyond the plane of a pitched roof. A dormer window (also called dormer) is a form of roof window. Dormers are commonly used to increase the usable space in a loft and to create window openings in a roof plane. A dormer is often one of the primary elements of a loft conversion. As a prominent element of many buildings, different types of dormer have evolved to complement different styles of architecture.
https://en.wikipedia.org/wiki/Dormer
A dormer is a roofed structure, often containing a window, that projects vertically beyond the plane of a pitched roof. A dormer window (also called dormer) is a form of roof window. Dormers are commonly used to increase the usable space in a loft and to create window openings in a roof plane. A dormer is often one of the primary elements of a loft conversion. As a prominent element of many buildings, different types of dormer have evolved to complement different styles of architecture.
