The more candid, the better.

Or at least that’s the preferred method for the latest Leadership in Energy and Environmental Design (LEED) rating system that rewards progressive building architects, designers and builders for projects that are environmentally-friendly.

LEED v4, which is set to launch at next month’s Greenbuild show in Philadelphia, encourages all those involved in a building’s construction to be as forthcoming as possible about the products they use.

That was the gist of the message from both Jim Mellentine and Annie Bevan during Thursday’s second of two hour-long webinars called “LEED v4, Are You Ready? We Are!” Mellentine, who is a corporate sustainability manager for the Sustainable Solutions Corp., and Bevan, a certified analyst with GreenCircle Certified LLC, both advised the many project managers listening in to be as transparent as possible.

“I think it will relieve a lot of headaches that will come in the future,” Mellentine said.

The two LEED experts cited a number of different ways to do just that, focusing especially on critical Life Cycle Assessments (LCAs), Environmental Product Declarations (EPDs) and Health Product Declarations (HPDs) as the most effective.

“There are lots of ways to get EPDs and HPDs,” Mellentine said. “All of those will help bolster your product’s attractiveness to architects and builders.”

Defined as a technique to assess environmental impacts associated with all the stages of a product’s life from cradle-to-grave, an LCA not only satisfies supply chain sustainability requirements by verifying a project’s environmental attributes, but also helps the project design team by identifying areas for cost savings and those in need of improvement.

An EPD promotes transparency by providing quantified environmental data for all building products. Originally scarce in number, there are now more than 150 various EPDs in American, Mellentine said, with more still set to debut in Philadelphia next month.

A key cog in the Material Ingredients Reporting section of LEED v4 that represents the “most significant” difference from LEED 2009, HPDs are steadily growing in demand because the publicly-available documents are a full disclosure of known hazards within a building’s structure and include a cradle-to-cradle certification.

“A lot of our clients have worries about chemical hazards in their buildings,” Bevan said.

The use of Certified Environmental Facts (CEF) to highlight the sustainability attributes of a project are yet another option, Bevan said.

Varying costs of LCAs, EPDs, HPDs and other quantifiable data about a building’s sustainability remain a concern among some architects and builders, but Mellentine warned that being less than frank about the makeup of the project’s materials could ultimately prove more expensive in the end.

“The architects and designers are demanding them,” he said, “and there will be ramifications if they are not developed for your products.”

LEED 2009 registration for new or existing products will continue until June 2015.