Green building buffs, take note: the US Green Building Council announced earlier this week that LEED 2009 has been approved and will go into effect next year.

The Leadership in Energy and Environmental Design program provides a system to evaluate green building design and offers recognition for particularly environmental friendly buildings.

The program awards points for rainwater collection, reuse systems, energy-efficient lighting, low-flow plumbing fixtures, and more.

LEED's newest incarnation incorporates regional credits — extra points identified as priorities in a project's environmental zone. It also has undergone a re-weighting of credits to reflect energy efficiency and climate change as priorities.

And LEED-accredited buildings get more than just green bragging rights. According to a recent study, LEED-certified buildings outperform their peers in areas such as occupancy, sale price, and rental rates.