He’s only 31, but Nathan Gauthier has had an adventurous life so far. He spent two years with the Peace Corps in Ecuador, studied red snapper in the Gulf of Mexico, shot underwater video for NASA, and worked as a fisheries biologist in Washington state and Hawaii.

These days, Gauthier’s adventures are a little tamer. In the past three years, he’s been a program manager with the Harvard Green Campus Initiative (HGCI). His mission on 22 design teams present and past: Devise the greenest schemes for building new buildings and refurbishing old ones.

In the course of his work at Harvard, Gauthier reviews mechanical plans; “models” daylight levels inside buildings and predicts shading patterns outside; calculates ventilation rates; prepares indoor air quality plans for the construction phase; and occasionally climbs around on green roofs to see what he can learn.

The job requires dealing with an eclectic mix of people, including architects, engineers, product vendors, and building owners. “I have to be able to speak everybody’s language,” he said. “I facilitate conversations that aren’t part of the traditional process.”

At the HGCI, Gauthier is manager of the new-construction program for all LEED-design buildings. (LEED is short for Leadership in Energy and Environmental Design, a set of standards established for sustainable structures by the U.S. Green Building Council.)

Gauthier — who in July will become one of two assistant directors at HGCI — is overseeing the LEED certification process for 90 Mt. Auburn St., where ground source heat pumps make this recently completed Harvard building 32 percent more energy efficient than a conventional structure.

Gauthier also helped plan the Dunster-Mather joint kitchen, with its high-efficiency dishwashers, variable-speed exhaust hoods, mechanical composter, and tank-and-pipe system for recycling waste oil.

He also organized and submitted all the LEED-required documentation for 46 Blackstone St., the first 100 percent renovation nationwide to receive a platinum rating, LEED’s highest.

These days, among other things, Gauthier is at work on the Arnold Arboretum’s Weld Hill project, new graduate student housing at 10 Akron and 5 Cowperthwaite streets, and other LEED projects at Harvard’s schools of business, law, divinity, and education.

Walking around campus with Gauthier is a lesson in the densely descriptive technical vocabulary that underlies sustainable design. He converses fluidly about bioswales, back-pressure turbines, enthalpy wheels, sensor technology, bamboo flooring, waterless urinals, and MERV 13 air filters.

On a tour of Dunster-Mather, the first LEED-certified interior in a U.S. institutional kitchen, Gauthier opened a restroom door, and pointed to the first dual-flush toilet ever installed at Harvard.

“None of the students will ever see it,” said Gauthier. “But it’s historic, and it helped convince others that the technology was worth pursuing.”

— Corydon Ireland