What is a heat island?
The Heat Island Effect
The term "Heat Island" describes built up areas (urban) where temperatures are much higher than it's surrounding rural areas. Everyone has expereinced this, even in a small scale. The feeling when you walk from a built up area into a park or open space with trees and plants, you instantly feel cooler. You are experiencing the effects of the heat island effect.
The heat island effect is created due to large populations, the increased amount of buildings, cars, industrial sites and polution.
Green Roof Benefits
How can green roofs help?
The heat island effect has three basic types of heat islands: canopy layer, boundary layer, and surface. Both canopy layer and boundary layer heat islands refer to atmospheric heating (warmer air temperatures). Surface heat islands refer to the actual temperature of surfaces in a specific heat island.
Green roofs which are made up of substrate and vegetation can offer some of the benefits the natural landscape offers in rural areas. With increased temperatures, plants and foilage struggle to survive in heat island areas. However sedum, which is used on green roofs, is a draught tolerate and hard wearing. Sedum green roofs help cool the air by evaporation cooling. They soak up the heat whereas traditional rooftops radiate solar heat back into the atmosphere.
Offer environmental benefits of a green roof system are its ability to improve air and water quality by filtering poullants. They also create an attractive alternative to traditional roof materials and can extend a roofs life expectancy by 3 times.