Every basement should have at least one egress window. In addition any sleeping space is NYS code-mandated to have an egress window; it is required as a second form of escape in the event that the stairs are blocked or unusable in an emergency. The window must have an openable area of 5.7 sq. ft. (net clear openable height of 24 inches and net clear openable width of 20 inches and sill height no more that 44 inches from the floor).