"Calgreen" is now the first of its kind green building code that every new building project in California will have to follow starting January 2011.

The new green building code will requre all new buildings to reduce water consumption by 20%, divert 50% of construction waste from landfills, separately meter indoor and outdoor water use (nonresidential only), and submit to mandatory inspections of mechanical systems equipment (nonresidential buildings over 10,000 sq ft, 930 sq. m. only).

The California Building Standards Commission approved the Green Building Standards Code unanimously in January. According to the state's Air Resource Board, the new standard will reduce California's greenhouse gas emissions by 3 million metric tons carbon-equivilent by 2020.

More than 50 jurisdictions in California already have stricter green building requirements. The state incorporated sustainable building approaches from several voluntary programs in development of their own standard.