Duke University’s Smart Home was another groundbreaking sustainability project. Finished in 2008, this 10-person student residence hall in Durham, N.C., is a model of green living, helping it receive the highest LEED rating of Platinum. The building scored a 59 on the green building assessment, making it not only one of the greenest dorms in the U.S. but one of the greenest buildings, too. What makes it so great? The 6,000-square-foot residence was designed by students and their advisers and makes use of solar panels, rainwater collection, green roofs, and sophisticated electronics to use as little energy and water as possible. The building isn’t just for housing students, however. It’s also a working laboratory for students who want to learn more about building sustainably to test out new technologies that can help make the dorm even greener in the future.