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Green Roof
SUSTAINABILITY & URBAN DESIGNbeginner
Definition
A roof covered with vegetation planted over a waterproofing membrane and drainage layer. Green roofs reduce stormwater runoff, improve urban biodiversity, insulate the building below, and mitigate the urban heat island effect. They range from lightweight sedum mats to full-depth planted gardens.
Example
Chicago City Hall (2001) installed one of the most prominent green roofs in the US — a 2,000m² planted roof that reduced the building's cooling load and inspired a citywide green roof policy.