New York City has enacted 29 building code revisions from a list of 111 proposed to "green" the statute. A report from the Urban Green Council says the changes are working.

In a report, the group, which suggested the changes two years ago at the behest of the city administration, estimates that the new provisions will save $400 million in a range of costs.

Eight more revisions are working their way through the City Council. The green effort is part of a 30-year master plan that city planners hope will reduce greenhouse gas emissions and building energy costs and save 30 billion gallons of water.

The Green Council is the New York City affiliate of the U.S. Green Building Council.