That the Greenbuild 2015 celebration party was held at Washington, D.C.’s Newseum — a 2008 building by Polshek Partnership Architects (now Ennead) that sits across the street from the city’s monumental core — shouldn’t have been much of a surprise. Aside from being among the few locations within walking distance of the Walter E. Washington Convention Center that could accommodate the crowd and offer a terrific view of the city, it was an eye-catching reminder that, as one attendee put it, “D.C. isn’t just a city of marble columns.”

If an informal poll of a few dozen partygoers suggested anything, it’s that the USGBC crowd, from new members to diehard early LEED adopters, remains largely positive about how the movement is growing. Jon Penndorf, a senior associate and sustainability leader at the D.C. office of Perkins+Will, expressed pleasure at how the conference’s educational content has moved over the years beyond the purely tectonic to broader, more human-focused areas. “I went to a presentation on circadian rhythms today,” he said with mild amazement.