IRC 310.1 The interior opening of at least one window in a sleeping area must be no higher than 44 inches above the finished floor. A firefighter is outside and the ground will be lower than the interior and they must still be able to enter to rescue.

IRC 310.1.1 The opening part of a window must at the minimum be 5.7 sq. ft. to allow a firefighter to climb in while wearing and oxygen tank. See the table for dimensions.

IRC 310.1.2,3 There are many window dimensions/sizes. One window in a sleeping area has to open large enough to let in a firefighter. The egress window cannot be narrower than 20 inches. The egress window cannot be shorter than 24 inches. See the table for dimensions approved. Windows can be made larger than the “Minimum” opening.