On January 14, 2010, the California Building Standards Commission approved the most environmentally stringent building code in the United States for new commercial buildings, hospitals, schools, shopping malls, and homes. The new code, named CAL Green , requires builders to install a number of environmentally friendly features in new buildings, including plumbing to cut indoor water use, efficient heaters and air conditioners, and requires them to divert 50 percent of construction waste to recycling. Local jurisdictions will be able to keep their stricter existing standards, or adopt more stringent versions of the state code.
The California Air Resources Board estimates that the code will reduce greenhouse gas emissions by 3 million metric tons in 2020. The new code will go into effect in January 2011.