But as much as lower costs made green construction more attractive, Henry and other industry leaders also say another criterion played a hugely important role in the mainstreaming of sustainable building: the sheer number of LEED-accredited professionals working at the firms.

These employees, schooled in the technology and best practices of sustainable construction and accredited by the U.S. Green Building Council or other third-party firm, have helped change the internal cultures of the companies for which they work.

“We actually lead the country in terms of having LEED-accredited professionals -- 1,085 out of about 5,200 employees,” says Kevin Dow, Southern California vice president/general manager for New York City-based Turner Construction Co., which ranks No. 5 on the list. “We’re very proud of that and think it makes a statement in itself.

“The people that we’re hiring today see accreditation as an investment in their future,” he says. “That’s why our accredited-professional rate has gone up so quickly. The younger generation of employees wants to build sustainable buildings. For the older employees, it’s a cultural shift. For the younger employees, it’s what they want to do.”

HOOPES

DOW

It’s a desire Turner fully supports, having realized $397 million in green revenue in 2009. Dow says 40% of Turner’s project backlog involves “sustainable building types.”

“We don’t see this as a fad,” he says. “If $2 billion of our backlog is in sustainable projects, that’s pretty impressive – not just for Turner but for the whole culture. It’s a huge shift.”

Ron Hall, McCarthy executive vice president, also sees the shift toward green building as being driven not just by external market forces but by changing attitudes from within.

HENRY

LINDEN

“You have to realize that the population of graduating seniors – engineering grads and others – is a little more focused on sustainable building than the older generation,” he says. “I think the younger generation clearly comes to us armed with a personal commitment to sustainability. It’s a natural transition.”

Ted van der Linden, director of sustainability at Redwood City-headquartered DPR Construction Inc., says he views LEED accreditation as a vehicle for enabling employees “to speak the same green language we’re trying to advocate in the marketplace.”

“Over a third of our staff have some [LEED] credentialing right now,” says van der Linden, whose company ranks No. 4 on the list of Top Green Contractors. “The accredited-professional stuff, weirdly enough, is a great tool to help create a groundswell among employees to find out their passion for sustainable building.

“What I think that’s done for us, ultimately, is create a depth of knowledge among the different roles in the company to the point that we can field fully accredited teams – from project executives to architects to market coordinators. We’ve got over 50 LEED-certified projects, and another 70 under some form of certification.”

DPR registered more than $434 million in green revenue last year.