Green roof, as the name may imply, is a roof of a structure or building that is partially or completely covered with vegetation and soil, or a growing medium, planted over a waterproof membrane.
Green roofs are not a new revelation. The origin of these planted roof systems date back thousands of years to the Hanging Gardens of Babylon, one of the seven wonders of the ancient world (built by King Nebuchadnezzar II in about 600 B.C.). Whether the intentions of these roofs were merely aesthetic is undetermined, but European countries have been using green roofs for functional and aesthetic purposes for hundreds of years. These contemporary green roof technologies started in Germany’s urbanized areas over 30 years ago and have gathered overwhelming support from many European countries and their general public. Contemporary green roof technology has been incredibly successful in European countries.
Chicago, Portland, and other United States cities have recently seen the public and private benefits to incorporating green roofs into the urban fabric. As in Europe, an extensive green roof infrastructure provides a viable option for solving many quality of life challenges facing our U.S. cities, along with numerous other benefits.