Birds, bats and bees are all making their home on the new green roof at the Javits Center.
It's the second largest green roof in the United States.
The building's new eco-friendly feature has benefits to both energy and water conservation.
"I have a number of students who are measuring the surface temperatures with the infrared cameras, and then they're studying the temperatures on the ceiling and we're finding out there could be as much as over a 20 degree difference between the surface temperature and the ceiling. We've been finding as much as, and more than a 70 percent difference in the amount of water that's retained," said Joseph Cataldo, a professor of civil engineering at Cooper Union.
The Javits Center says those savings will prevent almost seven million gallons of storm water run-off each year, and cut energy consumption by a quarter.
The roof is open to the public by appointment.