A Dormer is any structure that juts out from a sloping roof. Think of windows you have seen that are built on a sloping roof –not skylights, which are positioned on the roof itself but windows that are positioned on the face of a structure built out of the sloping roof. That structure is a Dormer.
Why do people build Dormers?
Dormers have come in and out of architectural fashion over the centuries and today many homes exhibit them. Dormers are increasingly seen in loft conversions as they serve as an excellent way to get more living space out of the underneath of a sloping roof.
There are various types of Dormers, each distinguished by its unique shape.
An often cited problem with Dormers is that they are prone to leaks. In addition, repairs can be expensive.