green roof

noun

plural green roofs

: a roof designed to be partially or fully planted with vegetation

A green roof over the arena will double as park space with trees, benches and a lawn.

—The Pittsburgh Post-Gazette

… green roofs are commonplace in Germany and celebrated for their environmental and financial benefits.

—Megan Johnson

Green roofs run the gamut from a layer of dirt with simple grasses to heavier installations that can include trees and shrubs, or even rooftop farms that produce vegetables. In addition to absorbing rainwater and preventing flooding by taking pressure off the city's aging storm sewers, green roofs also provide a layer of insulation that reduces heating and cooling bills.

—Marco Chown Oved and David Rider

Word History

First Known Use

1984, in the meaning defined above