Few days back a Virginia Tech architect revealed that 'green roofs' need not go to great depths to work. Elizabeth J. Grant, an assistant professor of architecture and design at Virginia Tech said, "With growing numbers of people moving into cities, it is crucial to give architects and builders tools to make good decisions about green roofs," Grant said. "These systems are on the rise not just because they represent a link to the natural world that is scarce in the city, but because they work. Extremes of temperature and rainfall are becoming unpredictable as climates change, and vegetated roofs help us build resilience in a rapidly changing world."
A green roof is a vegetative layer grown on a rooftop to provide shade and remove heat from the air through evapotranspiration, decreasing temperatures of the roof surface and the surrounding air. Green roofs, therefore, are effective technique to get respite from summer. The process also helps in saving energy consumption by cutting cooling cost of the buildings significantly. Green roofs also reduce storm water runoff and flow rates, which in turn helps prevent sewers from overflowing and stream banks from eroding.
Green roofs can be installed on a wide range of buildings, from industrial structures to private homes. These vegetated roofs can be as simple as a 2-inch covering of ground cover or as complex as a fully accessible park complete with trees!
Apart from cooling the building, the green roof reduces energy consumption, air pollution and greenhouse gas emissions. Green roofs can slow storm water runoff in the urban environment and also improve indoor human health, comfort and quality of life.