12 pitch ?
Depends on what type of dormer you are talking about. If the dormer has a pitched roof, such as a "gable," it's framed with the same roof pitch as the original roof, so it blends in.
A "shed," dormer on the other hand is usually had on homes with
a roof pitch of at least 8 in 12 or steeper. This type of dormer
needs a roof pitch shallower than that of the original. A general
rule of thumb is to keep a shed dormer at least 4 in 12. (A
shallower or steeper pitch will make the dormer look out of