University of Colorado Boulder is working hard to build a reputation as an environmentally conscious school, and building a new LEED Platinum goal is helping them to further that mission. Housing 500 students, the Williams Village North residence hall is the largest building in the U.S. to achieve Platinum status. The huge building is estimated to be about 40 percent more energy and water efficient than conventional buildings of the same size, and is one of 10 other LEED rated structures on campus (eight are Gold-rated and two are Silver). Like other LEED buildings on this list, the dorms at CU have solar panels, power-saving shut-off systems, and native landscaping but boast a few unique features as well, like energy monitors for rooms and water bottle refilling stations.