The U.S. Green Building Council (USGBC) announced the opening of the fifth public comment period for the proposed update to its LEED green building program. The comment period, which will close on Dec. 10, enables the building community to view the most recent draft of the rating systems and provide comments where any substantive changes have been made.

"LEED v4 will have the greatest impact of any rating system we've developed by focusing on building performance and rewarding innovative product manufacturers who offer best in class products," said Scot Horst, Senior Vice President, LEED, USGBC. "LEED v4 will help change the way project teams think, integrate, plan, execute and operate their buildings."

LEED v4 continues to push the envelope on energy efficiency, allocating nearly 20 percent of all points to optimizing energy performance over the stringent ASHRAE 90.1-2010, which would do more to help curb CO2 emissions than any LEED rating system in its 12 year history.

In addition to bringing green building solutions to more market sectors, including data centers, warehouses and distribution centers, hospitality, mid-rise residential, and existing schools and retail, the next version includes more options for projects outside of the U.S., making LEED the common language for sustainability around the globe.

The rating system has long championed innovation, and the LEED v4 draft further encourages innovative thinking and decision making about building materials and design. In this draft, using fewer, better materials will result in up to 9 LEED points, incentivizing product manufacturers that voluntarily report about their product makeup and those who reduce the negative impacts - from extraction of raw materials through the manufacturing process.

"Engaging people is at the core of the LEED development process, and this draft reflects the thoughtful comments and recommendations we've received from over 21,500 stakeholders," added Horst. "LEED v4 raises the expectations for what LEED project teams are being asked to deliver. We will launch the LEED v4 beta testing period in November which will provide an additional opportunity to explore the new program inside and out, and help refine support tools and resource."

When fully launched in 2013, LEED v4 will offer an improved user experience that will make the certification review and documentation process more intuitive and efficient. The simplified reporting requirements will be thoroughly refined and tested by the LEED v4 beta testing group - the first crop of projects to pursue LEED V4 certification. The beta process enables project teams to engage with a pre-ballot version of LEED v4 with guided support from USGBC.

USGBC's Greenbuild International Conference and Expo, taking place Nov. 14-16 in San Francisco, Calif., will give users an additional opportunity to explore LEED v4, including the new technical content and credit language, while learning about the streamlined documentation requirements and submittal forms and the dynamic, mobile education resources being developed.

LEED v4 drafts and the public comment tool are now available on the newly re-launched, re-envisioned USGBC.org website, a platform that engages the green building community and supports an entire ecosystem of websites and apps. The new USGBC.org gives everyone the opportunity to build a rich history of involvement in the green building movement.

In an effort to provide the marketplace a view of the full LEED program experience prior to ballot, USGBC announced an expanded timeline for LEED v4 and committed to a fifth public comment period. Fifth public comment will run until Dec. 10. Ballot period is expected to open June 1, 2013.

Approximately 35 credits are included in the draft open for public comment, and have been revised in response to feedback from previous public comment periods to further improve clarity, increase flexibility and options for project teams, and removing unsuitable requirements from previous drafts.

To view the drafts of LEED v4 visit www.usgbc.org/leedv4.