July 21, 2008 - California has become the first U.S. state to mandate energy- and water-efficiency standards for all new building projects.

The new California Green Building Standards Code sets targets for builders to reduce energy use by 15% and landscape water use by 50% beyond currently mandated levels. The new code is slated to take effect in 2010.

The regulations are designed to increase energy and water conservation in an industry known for its large carbon footprint. Buildings account for 70% of U.S. electricity consumption and 12% of potable water consumption, and produce 39% of carbon dioxide emissions, according to the U.S. Green Building Council.

"Cars and buildings are two of the leading users of energy," California Governor Arnold Schwarzenegger said in a statement. "We’re already addressing cars, and these new building standards will ensure that California remains at the forefront of reducing our carbon footprint and conserving valuable natural resources while also protecting our economy."

The Governor's Office reports that California's building efficiency standards (along with those for energy-efficient appliances) have saved more than $56 billion in electricity and natural gas costs since their introduction in 1978 - and are expected to save another $23 billion in just the next five years.

In addition to the new standards, Governor Schwarzenegger has mandated that all state-owned buildings reduce energy use 20% by 2015. New state construction and major renovation projects must also earn LEED Silver certification from U.S. Green Building Council. Thirteen projects have received the certification so far.