Worldwatch: As more people move to urban areas in search of economic opportunities, the number of buildings that are needed to house them continues to rise. It is estimated that by 2030, an additional 1.4 billion people will live in cities, of which 1.3 billion will dwell in cities of developing countries. The increasing number of buildings has long-term impacts on both the environment and natural resources. Fortunately, a variety of policy tools hold promise for promoting sustainability in buildings, according...