Dive Summary:

• Green Roofs for Healthy Cities, an organization that advocates the use of green roofs, says that demand is growing along with the roofs themselves.
• The market for green roofs grew 115% last year, the group said. Modular installations begin at about $20 per square foot, a Missouri supplier says.
• The Environmental Protection Agency says green roofs insulate the structures they are atop, help reduce storm runoff and cool the air.

From the article:

Carpets of green have topped dwellings since ancient times. ...