Casement windows are windows that are attached to their frame by two or more hinges on either side, allowing it to open and close like a door. They are used singly or in multiples within a common frame. These windows most often swing outward and are opened with a crank, lever or cam handle, which is placed around hand height or at the bottom. Most of these windows are locked tight with sash locks (a handle and hook system to pull in and secure the sash to the frame). A crank, stay, or friction hinge is necessary when the window opens outward, to hold the window in position during windy conditions. These windows are considered to be egress windows (see egress sizing chart) as long as the minimum size requirement is met.
In situations where rain is combined with wind, an open casement window may allow a great deal of moisture to enter your home and cause water damage.