By now, most roofing contractors know the basics about green roofing systems along with their many benefits. What started in Germany more than 40 years ago, but was viewed by many as just a fad for several years in the United States, has now become quite common on rooftops throughout North America. Much of this popularity is the result of the fact that as more and more green roofs have been installed, their benefits and features have been more thoroughly realized, analyzed and reported.