Building green is getting cheaper and more popular

"A study by the National Association of Home Builders (NAHB) found that some 90% of home-builders are now using green ideas. In 2005 the study found a 20% increase in the number of new homes that were environmentally responsible: water-efficient, energy-efficient, built of nature-friendly materials. Last year, the figures were up another 30%. Green building has become big business. Banks such as Bank of America are adding more green financing packages. Shops selling green building supplies are springing up, as are giant shows (...) lower building costs are helping the movement. It used to cost at least 15% more to build using eco-friendly ideas and products, but today they add only 1-3% to the cost of construction (...)"

Source: adapted from http://www.economist.com/world/na/displaystory.cfm?story_id=9804157