The U.S. Green Building Council recently launched LEED Version 3, a significantly updated and reorganized version of its LEED rating system. With an emphasis on energy efficiency and CO2 emissions, LEED Version 3 will have an important and lasting impact on constructing new and retrofitting existing commercial buildings, and will require that project developers change their approach in order to ensure their future projects gain LEED certification.

LEED Version 3 has three components:

  • LEED 2009 the updated rating system.
  • LEED online the platform through which the certifying bodies and building project teams will communicate.
  • LEED certification model project certification now to be administered through the Green Building Certification Institute (, rather than through the U.S. Green Building Council. The major changes (styled as enhancements by USGBC) to the rating system, embodied in LEED 2009, are:
  1. Harmonization. All of the credits and prerequisites from all LEED commercial and institutional ratings systems are now consolidated and aligned, based on the most effective common denominators, so credits and prerequisites are consistent among the ratings.
  1. Credit Weightings. The credits now have different weightings based on their ability to impact different environmental and human health concerns. A principal result will be significantly more points awarded for strategies that positively affect energy efficiency and CO2 emissions. Another result will be that some projects that would have achieved LEED certification under the prior rating system will not, due to the new credit weightings, achieve certification under LEED 2009 without significant design changes. Resource depletion, water intake and indoor environmental quality are other high-priority issues emphasized by the new credit weightings.
  1. Regionalization. Specific environmental points of emphasis have been identified for various regions of the country by USGBC regional councils, chapters and affiliates, and six LEED credits have been prioritized because they address the specific regional issues. A limited amount of extra points will be available for earning these priority credits.
  1. Alternate Compliance Paths. Likely to encourage reuse of existing buildings, this performance-based path will employ a unique "Life Cycle Assessment" credit calculator (available for try-out but still in testing) to take into account the embodied energy and lifespan of existing building materials.

LEED 2009 is far more performance based than the prior system, which relied much more on design and construction requirements and benchmarks. Whereas under the prior system a LEED certification could be achieved even if only minimal energy savings were achieved, this performance based system will require that energy efficiency and CO2 emissions be prominently factored into every step of project planning, design and construction. This performance focus should help eliminate anomalies that existed under the prior rating system where the same number of points could be awarded for project features that required dramatically different levels of effort and expense ( e.g., remediating a brownfield site versus installing low-emitting floor covering).

Going forward, it is intended that the LEED rating systems will be modified every two years. Of particular note, starting in 2011, it is expected that the credits will be further weighted according to newly developed social and cultural criteria.

A project already registered or registered before June 27, 2009, may continue toward certification under LEED Version 2, although the option does exist to transition the project to LEED Version 3 (with no new registration fee required if transitioned by December 31, 2009). New projects on or after June 27, 2009 are required to register under LEED Version 3.