Look around any big city and you may see a green fringe on the rooftops. Many homes and businesses have begun adding plant life to their buildings in the form of green roofs. However, this concept works not only in urban areas but also in rural and suburban regions.
Experts categorize green roofs into three types: extensive, intensive, and semi-intensive. In general, an extensive green roof has a limited variety of plants and shallow growth, often less than 6 inches, and it may not be accessible to people. An intensive green roof boasts a diverse selection of plants (even including smaller trees), a deeper growth, and more accessibility to building patrons and residents. A semi-intensive green roof is a combination of the other two types.