The "greenest" building ever constructed at Cambridge’s MIT Sloan School of Management is now open.

The 215,000-square-foot, $142 million building overlooks the Charles River and includes more than 200 offices, classrooms and space for group study and other activities, according to a statement. More than 90 percent of the debris from a structure torn down to make way for the new building was diverted away from landfills, and its garden was relocated to a new park-like area on campus.

Some of the building’s sustainable features include active chilled beams for cooling, automatic window shades in offices, a green roof and an irrigation system connected to a central weather station for minimization of watering, according to a statement.