When he took the stage for the closing session of this year’s Greenbuild, amid flashing lights and a thumping rock anthem, USGBC CEO Rick Fedrizzi got right to the point: “When people say green building is over, tell them there were 29,752 people at Greenbuild. That doesn’t sound like we’re at the end of the road.”

It’s a message that green building advocates are chanting every chance they get — and personally, I hope they’re right. Green building makes sense on all sorts of e-word levels: energy, environment, economy, employment.

But there was some sense that this crowd — as massive as it was — was still fairly … insular, at least if keynote speaker soundbites are to be trusted (e.g., “what would we do without NPR?” and “finally [since the election] we feel like we have our whole lives ahead of us, and anything is possible”). For a reality check, I talked to some of the staff and volunteers at the event.

There was Will, a young water-quality researcher from Virginia who volunteered so he could attend the education sessions. (Eight hours of volunteering got you entry for all four days — not a shabby deal.) “I’m a little concerned,” he told me as he directed a stream of architects and designers toward the proper recycling bins for their type of refuse. “This has the feeling of being a trend or a fad, and we really need it not to be.”

There was Axel, a fellow volunteer and middle-aged graphic designer from north of Boston who told me that green-minded builders in his area are “scarcer than hen’s teeth.” There were hospitality staffers Angie and Kim; when I asked what they thought of the conference, Angie blurted out, “I don’t care about recycling!” as if it had been weighing on her all day. Kim was more interested in the proceedings, but concluded that green building, while interesting, was too expensive.

Attendees, too, were in a realistic frame of mind. Gina, a civilian with the Air Force in Atlanta, hoped to gather concrete and convincing information to bring back to the engineers at her base. They “weren’t trained on sustainability,” she says, and are shifting their practices slowly — mainly at the behest of the government. “I hope I can learn enough to show them some new things,” she said as she waited for one of the final sessions to start.

Scott, a Home Depot “install expediter” from San Antonio, had accompanied his LEED-certified wife to the event. Reluctant at first to position himself as more than a “tag-along,” he went on to confess to some expertise, telling me that the new green products his store sells tend to be returned more often than conventional ones: “If you have to replace your carpet after two years instead of ten, it kind of defeats the purpose.”

Scott characterized the entire conference as “nice,” and oddly, that word came up multiple times in my conversations. The sense I got was that people are hungry for action on the ground, not cheerleading. Of course, there’s a place for cheerleading. And with the economy the way it is, cheerleading might have to be enough for now. But when the money starts flowing again — or even trickling — I know 29,752 people who are ready to spring into action. To quote one Midwestern real-estate executive I spoke with, “We just gotta do it.”