A floor at all exterior doors, other than the required egress door, should not be more than 7-3/4 inches lower than the top of the threshold. In this illustration, you can see the exception to the rule for a landing at an exterior door. If the door does not swing over the landing, then the exterior landing can be, at most, 7-3/4 inches below the top of the threshold. This is applicable to all exterior doors, including the required egress door. The screen and storm doors are allowed to swing over the landing. This is the most commonly used exception.