In fact, a green roof can be a relatively small-scale investment. A smaller-scale version, known as extensive greening, requires only a few inches of soil planted with low growing plants, such as sedum. Carr says most of the projects he's seen have been intensive. But he sees any green roof as an asset to the local environment. He expects more new buildings, especially public buildings, will utilize green roofs as government incentives become available.
Environmental benefits are the primary goal of roof greening.
Green roofs reduce stormwater runoff, insulate buildings leading to lower energy use, clean the air, and control local climate, lessening the formation of smog. But there are economic benefits, as well. In addition, the soil and plant cover on a green roof protect the roof membrane from the elements, which leads to lower roof maintenance and a longer lasting roof. Rooftop gardens can also add to the desirability of a building, allowing a property owner to charge higher rents. Green Roofs to Greenhouses Rooftop gardens aren't the only option to green up rooftops.