The residence halls, Clarke and Hood, feature six-way zoned heating, energy-efficient boilers, digitally controlled heating systems and ample weather-stripping. They also benefit from a brigade of students on campus, known as eco-reps, who cajole and exhort their peers to reduce their carbon footprints. Among their duties is the posting of fliers inside bathroom stalls, called installments. A recent missive urged students to “beware of the phantom load,” energy used by appliances that are turned off but still plugged in.

“Instead of someone talking at you, it’s someone your own age who says, ‘This is a good idea,’ ” said Becky Webster, a junior from Troy and one of a half-dozen eco-reps on campus.

Ithaca is one of only two colleges in New York State with dormitories that have earned the Energy Star label so far; the other is Hamilton College. And administrators here say they have submitted an application for a third dormitory whose energy use has recently met the Energy Star requirements for buildings.

While the Environmental Protection Agency is widely known for its Energy Star program for appliances, the agency has rated commercial buildings — perhaps less visibly — for more than a decade. Dormitories are among 22 building categories eligible for an Energy Star label, along with bank branches, courthouses, hospitals, hotels, petroleum refineries and schools. Dormitories joined the program in 2006; so far, more than 50 residence halls nationwide have won Energy Star approval, out of more than 9,800 buildings and plants.

The ratings system for buildings works differently from appliances. Using 12 months of utility bills, colleges enter information into the E.P.A.’s Web site about a dormitory’s energy consumption. The computer program takes into account factors like building size, computer use local climate and occupancy and then compares the energy use with similar buildings nationwide. A score of 75 or higher, on a scale of 1 to 100, means the dormitory is Energy Star eligible, and the agency system invites the college to apply for the label. A professional engineer must also perform an audit of the building, at the institution’s expense.

The Energy Star label for buildings is intended to raise awareness and prompt colleges to set energy goals.

“Colleges and universities spend almost $2 billion a year on energy,” said Maura Beard, a spokeswoman for the Energy Star program. “A lot of people think the solution lies in the latest gizmo or newest technology. But there are things as simple as, who’s paying attention to the lights being on all night? The idea is extricating this waste.”

Ithaca College’s quest for green dormitories is part of a broader agenda to be environmentally sensitive, one of the hottest social causes on campuses. Set in the Finger Lakes in a college town that likes to call itself “10 square miles surrounded by reality,” the campus has a new platinum certification in Leadership in Energy and Environmental Design, known as LEED, for a business school building, the highest available, from the United States Green Building Council, an environmental group. A second new building is expected to earn a platinum rating shortly. The college also has an active composting program, an environmentally themed residence hall and a new organic garden. And administrators are considering a major in sustainability.

The Energy Star labels for dormitories, which come with a plaque, are one way for college administrators to get recognition for investing in improvements that are not necessarily visible. At Ithaca, for instance, the college has spent $1.3 million in the last decade on dormitories and academic buildings to upgrade boilers, insulate attics and create a digitally controlled heating system that allows for automatic thermostat adjustments.

“It lets us make a visual statement that, ‘Hey, we are doing these things,’ ” said Marian M. Brown, special assistant to the provost and vice president for academic affairs at Ithaca, referring to the Energy Star plaques.

One of the keys to the Energy Star label for dormitories is submetering. While every dormitory at Ithaca College is individually metered for electricity, only about 15 percent have submeters for natural gas. The parsing of energy use is crucial because without information from both meters, a dormitory cannot compete for an Energy Star label.

Indeed, Ms. Brown suspects that some of the college’s other dormitories would earn a score of 75 or higher if they were individually metered like Clarke and Hood Halls. But such meters would cost the college about $1,000 each, she said. And in deciding how to allocate limited funds, one question for administrators is whether to spend money on things that yield actual energy savings or, in the case of submeters, provide feedback.

“I could easily spend $20 million on new windows if I had the money, and we have a number of boilers that need to be replaced,” said Rick Couture, the college’s associate vice president for facilities. “These are all the things that people don’t see and aren’t glamorous, but they’re the guts of the building.”

With Ithaca College’s commitment to instituting practices that do not have a negative impact on the global climate, more investments are needed. Some of the money will come from energy savings that the college has already achieved. Mr. Couture estimated that the college had saved about a half-million dollars annually in the last five years as a result of the building improvements.

While the Energy Star appliance labels have been criticized for their potential for fraud, the rating system for buildings has earned mostly praise. A Congressional report released in late March detailed how auditors posing as fictitious companies managed to get Energy Star approval for a number of phony appliances, including a gasoline-powered alarm clock.

“The building program uses actual utility bill data, so there really isn’t room for abuse,” said Merrilee Harrigan, vice president for education at the Alliance to Save Energy, a nonprofit group in Washington. “It’s a fantastic tool.”

Ms. Harrigan said Energy Star allowed colleges to see how their dormitories stacked up to others nationwide. “Even if you know the energy use of your building, you don’t have any context,” she said. “That’s the great value of the Energy Star program. It gives you an apples-to-apples comparison with other schools in the country, and that’s the piece that is extremely difficult to get any other way.”