Environmental Footprint
Environmental Footprinting is a useful tool used to measure environmental impact in terms on land use. In this sort of study service laundered nappies have the smallest overall impact, with Home laundering coming next. Disposables use the largest area of land. The results are shown below:

Source : Best Foot Forward
Service laundering has a lesser footprint due to the fact that more nappies are being washed at a time, using more cost efficient machinery.