An insulated ventilation pipe does not freeze in subzero temperatures, so that foul air can be exhausted from the sewer in the winter so that it does not cause smell problems. The insulated ventilation pipe is 350 or 500 mm high with an inside diameter of 110 mm and outside diameter of 160 mm. The ventilation pipe is available with or without a cowl. The height of the cowl is approx. 150 mm. The screws for installing the pipe to the roof pass-through set are included. In addition to the pipe, a pass-through set is needed, chosen according to the roofing, and, if required, a flex pipe for easy connection of the ventilation pipe to the sewer pipe. A flex pipe is used for easy connection of sewer ventilation pipe and sewer pipe that are not aligned. The flex pipe allows horizontal and vertical movement of the ventilation and sewer pipes. Due to the flexible connection pieces, structural movements do not affect their operation. A flex pipe can be connected to a 75 or 110 mm sewer. The flex pipe is connected to the ventilation pipe with the supplied clamp.