Wiktionary
n. 1 A roof of a house or other building which is painted or otherwise colored green. 2 A roof of a house or other building which is covered with soil and grass, plants, trees, or other landscaping materials. 3 A roof of a house or other building on which solar panels, solar hot water collectors, wind powered turbines, or other natural energy collectors are placed. 4 A roof of a house or other building which is designed to collect rainfall for use in gardens, lawns, or as drinking water.
Wikipedia
A green roof or living roof is a roof of a building that is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. It may also include additional layers such as a root barrier and drainage and irrigation systems. Container gardens on roofs, where plants are maintained in pots, are not generally considered to be true green roofs, although this is debated. Rooftop ponds are another form of green roofs which are used to treat greywater.
Green roofs serve several purposes for a building, such as absorbing rainwater, providing insulation, creating a habitat for wildlife, increasing benevolence and decreasing stress of the people around the roof by providing a more aesthetically pleasing landscape, and helping to lower urban air temperatures and mitigate the heat island effect. They effectively utilize the natural functions of plants to filter water and treat air in urban and suburban landscapes. There are two types of green roof: intensive roofs, which are thicker, with a minimum depth of , and can support a wider variety of plants but are heavier and require more maintenance, and extensive roofs, which are shallow, ranging in depth from to , lighter than intensive green roofs, and require minimal maintenance.
The term green roof may also be used to indicate roofs that use some form of green technology, such as a cool roof, a roof with solar thermal collectors or photovoltaic panels. Green roofs are also referred to as eco-roofs, oikosteges, vegetated roofs, living roofs, greenroofs and VCP (Horizontal Vegetated Complex Partitions)
Usage examples of "green roof".
He waved to Irina, who blew a kiss, and to Aleksandr and the children, then lifted slowly above the farmhouse, with its sharply sloped, conical green roof, designed to shed the heavy weight of winter snow, and headed southwest.
The plants around him leaned in, forming a green roof over his head.
His gaze roved to the green roof above their heads, a solid ceiling of thick leaves and interwoven arches.
She strove to pierce the sullen green roof of the arched branches and see the sky which presumably lay above it, but presently gave it up with a muttered oath.
She strove to pierce the sullen green roof of the arched branches and see the sky which presumably lay about it, but presently gave it up with a muttered oath.
It was only another few curves before he saw the green roof of the laboratory and turned left, his headlights swinging across the grassy clearing, and shining onto the dinosaurs pushing the trailer.
Far to her right, rising up above the encompassing silt banks, were the other familiar landmarks he knew so well, even the green roof of the Ritz, fading into the haze.
Near the top of the slope was a grove of young alders, grown so close together that the lower branches interlaced, forming a green roof over the bracken beneath.