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.

From there, he walked through not only a gallery of his projects, but the sustainability principles each exemplified. Of his project the Dutch Institute for Forestry and Nature Research, he spoke of integrating the building with nature. Water that flows from the outside into an open space inside helps cool the building, and that cooler air is then carried throughout the building. The German architect spent a few minutes waxing on the value of wood — “it’s highly insulating, very stable, fireproof if you use solid wood, has fantastic thermal storage, it’s ideal” — but assured the crowd it wasn’t because his speech was sponsored by the Sustainable Forestry Initiative. Behnisch spoke passionately and at length about buildings’ embodied energy, questioning the wisdom of knowing down and building new, even if it’s sustainable. “Whenever someone tells you there is a CO2-neutral bldg, it’s only looking at from when it’s finished. Only running energy, not embodied energy,” he said. “Demolishing and rebuilding often doesn’t make sense, even if I like building buildings.” Behnisch said he likes Boston, where he said he has spent considerable time, but his admiration has limits. “Boston is a city with a pretty good public realm, but I wish someone would do a wind study before putting up another building,” he said. And he praised the city’s climate, saying it is moderate enough to support natural ventilation two-thirds of the year, but he said locals seem not to know it. “Office buildings need to have that Arctic environment” anyway, he observed wryly. Natural ventilation is prominent to Behnisch’s past and perhaps-future jewels of Greater Boston — 2003’s Genzyme Center in Cambridge, and the four-building, 589,000-square foot Allston science center. In Allston, the ventilation will come through openings in the stone facades, rather than through the windows. Genzyme, meanwhile, is also known for its daylighting. Heliostats track the sun and reflect it into the building’s full-height atrium, where it is dispersed by chandeliers and by louvers on the north wall. “You get very different light effects. What always amazed me is that light actually behaves as it should. It’s funny. You do calculations that it bounces there and bounces there and bounces there and you get light down there, and it works!” I’d have empathy for anyone who had to follow Jones, and for those of us who attended both speeches, it was hard not to note that while where time ran out before questioners did in the earlier session, no one came forward when Behnisch offered to take queries in the later one.