At the moment, the roof above Dormitory A of the redeveloped Butler College complex is a “green” roof only in the most technical sense of the phrase.
The 14 varieties of hardy sedum planted on the Butler rooftop earlier this year have now exploded into a kaleidoscope of color. The contrasts in the palette of the many-hued rooftop garden are only expected to intensify as summer turns to fall.
When 283 Princeton undergraduates move into Butler College this September, they will be entering a 113,000-square-foot complex integrating sustainability features from top to bottom, including the green roofs on more than half of its buildings and a stormwater cistern that will collect and recycle rainwater to irrigate courtyard landscaping.
Green roofs have been installed atop portions of Butler’s dormitories A, C and D, with the monitoring equipment, including a weather station, on A. Green roofs — also called vegetated roof covers — are thin layers of living plants that are established on top of conventional roofs. Properly designed, they are stable, living ecosystems that replicate many of the processes found in nature
read the full article with statistics and graphs at the SOURCE: Princeton University – From top to bottom, Butler will be a living environmental laboratory