How green a campus is today is a crucial factor in a college's admissions, affecting not simply the number of applicants but also the percentage of accepted students who choose to attend a given four-year institution. Since the average applicant now applies to seven schools, the competition for top candidates obviously is fierce. Recently, the yield nationwide dropped four points to 45 percent, meaning that more than half the students who were accepted at various colleges and universities demurred. As the number of graduating high school seniors decreases from a peak this year of 3.33 million, the battle can only intensify, especially as guidance counselors are reporting that a growing number of students are putting college on hold because of the economy.

So a green campus is among the features that this shrinking pool of selective students value. This is not a reference only to the aesthetic mix of trees, grass and shrubbery — important as they are — but to the ethical concern that an institution exhibits over energy conservation and impact of its greenhouse gas emissions on the environment. The verb "exhibits" should be emphasized. Colleges not only need to walk the walk, they want to be able to talk the walk, to show the world they are doing their part in protecting the environment.

A final argument for the greening of American campuses in a demonstrative fashion is the fact that sustainability recently has been added to most education curriculums. In fact, it is among the fastest-growing academic majors, according to a recent national poll. Green infrastructure, therefore, can serve a dual role: as a responsible way to conserve and generate energy, and as a "real-world" teaching tool.

Quinnipiac University in Connecticut opened its York Hill campus this fall with an array of sustainable approaches and alternative energy systems, some purposely quite visible. The star of the show is a cluster of 25 vertical-axis wind turbines, or "windspires," that not only generate power cleanly, but also make up a kinetic "sculpture garden" that will provide an aesthetically pleasing venue for students to visit. Set on a grassy hilltop with views of Long Island Sound, it sits along a well-used student path. Passersby can stop, sit on benches, and shoot the breeze themselves.

In addition to showing the public what it is doing, some schools are taking the next logical step: telling people what it all means in terms of kilowatts generated, greenhouse gases displaced, payback projections and the like. Infrastructure as a formal "exhibit trail" is one of the options that Quinnipiac is considering. Nearby, Yale University's Kroon Hall for its Forestry School is telling its green story with on-site kiosks and an intriguing Website: www.yale.edu/sustainability.

Visually impressive as the sculpture-like turbines are at York Hill, along with rooftop photovoltaic solar collectors, many of the most sustainable and arguably more significant initiatives are out of sight. The little-known secret about sustainable architecture is that the most basic, and least expensive, approaches are actually the most productive. For example, how you site a building in the landscape and orient it toward the sun — a strategy that costs little or nothing in most cases — can have the greatest impact on energy usage. Placement of windows and building mass can greatly improve passive solar heating and cooling, as well as "light harvesting," the use of natural light to reduce the need for electrical generation.

Responsible construction at campuses is not just about the bells and whistles, but nitty-gritty components such as the use and conservation of durable and local materials and an eye for how the facility can be maintained efficiently over time. Everything from rainwater harvesting and automatic sensors to turn off lights, to low-flow plumbing fixtures: just some of the myriad details that add up to significant conservation and budget savings.

The most sustainable building of all, of course, is the one that you don't have to build, or to put it another way, one that lasts for generations. An eminently practical and efficient structure that has no soul or flair, a place that people don't want to inhabit, or look at, is likely to be torn down and replaced before long. The one most overlooked feature in successful green construction is the creation of a building that will be beloved by its owners, users and passersby. If it is dear, as opposed to dreary, it will last for years and years.

Riley, FAIA, is a partner with Centerbrook Architects, Centerbrook, Conn. He can be reached at riley@centerbrook.com.