A wetland roof is a special type of extensive green roof. A roof is evenly planted with wetland or marsh plants which will be regularly irrigated on a daily basis. Besides the aesthetic aspect, this particular type of roof may also offer significant functional advantages. Wetland roofs are natural air-conditioning systems. During the spring and summer months, the heat of the rooms below will be eliminated by the evaporation and plant transpiration of the water. When it becomes colder in autumn or winter, a wetland roof is, due to its additional heat insulating effect, an excellent protection against an extensive heat loss.