Northland College in Ashland, Wis., is giving 90 students the chance to live in one of the most eco-friendly dorms in the U.S. The $4.1 million Environmental Living and Learning Center, opened in 1998, features waterless composting toilets and furniture and countertops made from recycled material. A 20-kilowatt wind tower and solar panels provide about 8 percent of the dorm’s power and cut water-heating costs by nearly 30 percent. Meanwhile, a new green office building for San Francisco’s Department of the Environment opened this week, the first city government building to be completed since San Francisco passed an ordinance in July 1999 requiring all city buildings to be eco-friendly. And on the opposite coast, in Annapolis, Md., the Chesapeake Bay Foundation is constructing a new office that it says will be one of the greenest buildings ever built. It will use unheated rainwater in bathroom sinks and include computerized red and green lights that tell employees when, in the interest of energy efficiency, they should open or close windows.