History of green roof
Linda and Velazquez, (2005) explains that mixing plants with structural design is not a new invention or idea, and neither are green roofs. Ornamental roof gardens have been present for centuries, the well-known of which were the hanging Gardens of Babylon in the eighteenth and tenth centuries B.C. The sloping walls of the Ziggurat of Nanna, which was constructed around 2100 B.C, were roofed with trees and shrubs. However it was merely the growth of contemporary building materials and techniques that permitted the further extensive creation of green roofs.
Linda and Velazquez, (2005) suggest that Germany were the first country to introduce true modern green roofs in the early 1970s and 1980s, therefore, there is no uncertainty that Germany is in the current centre of green roof movement throughout the globe. Approximately 14% of all flat roofs are green in Germany, and 80% of those are extensive systems which tender the most cost effective solution compare to intensive types (Herman, 2003). Other European nations lag far behind Germany when it comes to implementing green roofs (Dunnett and Kingsbury, 2004).
Stovin, (2010) explains that Storm water from urban roofs makes a major contribution to sewerage resulting flooding and urban water quality issues. The majority developed counties,