One "future growth opportunity" for our green practices at home is capturing the rain as it falls, to be used for irrigation. To me, the barrels are mostly unsightly and they are a potential breeding ground for mosquitoes. I was thinking that I would need to get a big tank, pay someone to dig up the yard, and then put in pumps — all pretty invasive, not to mention expensive.

By any accounting, the closing act at GreenBuild/Boston had to be its finest moment, and it undoubtedly was among all I experienced during the three days. EO Wilson and Janine Benyus spoke individually, and then in colloquy led by Kevin Klose, president emeritus of National Public Radio.

A posting in the press room at GreenBuild Friday morning said that as of Thursday, 27,995 people had attended the show. A couple hours after I read that, I thought I heard USGBC president Rick Fedrizzi say from the stage during the closing session that attendance had topped 30,000. Maybe I got that wrong, but either way, the interest in green building certainly appeared to triumph, or at least maintain, despite the sour economic times.

I had never heard of Mr. Petrovic until encountering him at GreenBuild. He is vice president of Dadanco, a company I had never heard of until encountering it at GreenBuild. It makes HVAC "solutions." I became aware of Mr. Petrovic because his company sponsored Van Jones's speech, and had the opportunity to say a few words before Jones began. And he did — he said a few words, and sat down. A day later, I happened by the Dadanco booth, still without realizing what Dadanco did.

Even at (especially at?) Greenbuild, you can find greenwashing. 'Course, that's a subjective term, and some of it is more egregious than others. But one of the first booths I happened upon Wednesday morning was promoting the coal industry. As I've said before, is there anyone, anywhere, who favors coal in any form expect "left in the ground," apart from people who are economically tied to it?

The giddiness over the election of Barack Obama was still fresh in the building-industry-related events this week in Boston. Thursday morning, a session exploring New England's clean-energy future started off with a recitation of the president-elect's statement the day before on cap-and-trade and other energy priorities, which prompted the first of two bursts of applause.

One subtext this week was overload. First of course, there were the two shows, BuildBoston and GreenBuild. Two three-day shows — one an annual Boston event, the other a one-in-a-generation visit by as big a force as there is in building these days. Somehow, they overlapped on two of their days — the last two days of BuildBoston were the first two days of GreenBuild. From what I could gather — I spoke to some people who might know, but in casual conversation, not in interviews — you could view this as yet another little skirmish between architects and the USGBC.

Another in a series of miniprofiles of sustainability-minded people who are working to reduce humankind’s footprint on the planet. They're "mini" not only because they're short, but because all the questions are 10 words or less, and the answers are requested to match. (Please, no counting.)

JANINE BENYUS, 50, Stevensville, Mont. Cofounder, Biomimicry Guild; Author, "Biomimicry, Innovation Inspired By Nature"

What do you do? "I’m a biologist at the design table, helping innovators consult life's genius to create sustainable designs."

Green epiphany: "Asking the question, 'is anyone consiously trying to emulate the elegant, well-adapted, fit technologies of nature?' It was about 1990."

Stefan Behnisch, in conversation with audience members after his presentation.

Stefan Behnisch, who certainly could claim leadership in the clan of the world’s most sustainability-attuned architects, just by offering only his Boston work for evidence, followed Van Jones in the east auditorium at the convention center. He was affable, gentle, and self-assured. While Jones spoke about what can be accomplished, Behnisch described some of what he has accomplished, recapping several of his projects while pointing out the elements of sustainability exemplified by each.