The invention discloses a novel external casement window. The novel external casement window comprises an upper border, a middle border, a lower border, a left border, a right border and window sashes, wherein the middle border is arranged between the upper border and the lower border, the left border and the right border are respectively arranged at the left sides and right sides of the upper border and the lower border, the window sashes are arranged between the middle border and the lower border, decorative lines are arranged on one side surface of the middle border, decorative lines are arranged at one side of the lower border, and the upper border, the middle border, the lower border, the left border, the right border and the window sashes are all arranged in the same plane. All the borders are located in the same plane after being assembled, so that the aesthetics is improved, and the general windowing visual effect is changed; and the decorative lines are additionally arranged, so that the aesthetic effect is improved, and the structure is reasonable.