The ongoing trend of building retirement projects on college campuses shows no sign of a slowdown.

Developers seem to have hit on a winning formula. Retirees enjoy the energy of campus life while school administrators are able to offer their retired faculty and older alums a way to stay connected to the school.

There are 50 college-based retirement communities nationwide, according to Ziegler Capital Markets Group, a Chicago-based firm that arranges project financing. Another 10 campus-based retirement projects are under way, with eight more on the drawing boards. Another 10 are being considered.

"Very few people have a negative memory of college life," said Kathryn Brod, senior vice president at Ziegler, explaining the appeal of the idea. "The campus is a draw for seniors who see so many amenities, particularly if it happens to be the [senior's] alma mater."

The developments offer lots of activities through the school, such as cultural and sporting events. Many college towns have a lower cost of living than big cities. University towns also tend to have top-notch medical facilities.

Classic Residence by Hyatt just completed its big project at Stanford University in Palo Alto, Calif. The $370 million development has 388 one-, two-, and three-bedroom homes. About 85 percent of the units are reserved, according to Penny Pritzker, chief executive at Chicago -based Classic Residence by Hyatt. "Colleges are a good match for senior housing," she said.

The Stanford project is typical of other college-based developments in several respects. The development is adjacent to the campus. Stanford owns the land and Hyatt has a 75-year lease on the 22.4 acres the project sits on. But the retirement buildings are not adjacent to teaching buildings. Most college projects are like this, maintaining some distance between the students and the retirees.

Also typical is that Hyatt's Stanford project is a continuing-care retirement development. Most college-based projects follow this retirement model in which the resident pays a hefty entrance fee (usually at least partially refundable), along with a monthly fee. In exchange, the resident has access to a continuum of housing. You may start out in an independent apartment, but as your health fails, or you become more frail, you are able to move to an assisted- or nursing-care apartment in the same development.

The average entry fee at Hyatt's Stanford project -- remember, we're talking California property prices here -- is $1.13 million. It's about $480,000 at Hyatt's continuing-care project at the Glen in north suburban Glenview.

Of note, the Stanford project has seven apartments with 4,200 square feet of space. The entry fee for those units is about $4 million. Most of those units are taken, Pritzker said, reserved by couples from the area who own very large houses and who want a place where they can entertain, or host family members for a visit.

Pricing at college-based projects depends on the local real estate market. And entry fees will pretty much mirror home prices. Developers have found they can't depend on just alums or retired faculty for customers. They must rely on local residents to make up the bulk of buyers, according to Brod at Ziegler Capital Markets. "We have learned that the project has to be able to draw from the surrounding market area," Brod said. Some projects in university towns in more rural locations have had trouble drawing residents, she added.

At Villa St. Benedict in west suburban Lisle, residents are just moving into their apartments at the project at Maple Avenue and Yackley Road, kitty corner from Benedictine University. The average entry fee is about $300,000 (90 percent is refundable). Some residents who have moved in are already auditing courses at the college, according to Margaret Herter, who markets the project.

But the strength of the connection between the college and the retirement community varies widely. Some projects, like Villa St. Benedict, offer residents the chance to audit college courses. Others may not. Some projects offer lots of interaction with campus activities and programs. Others don't.

At Hyatt's Stanford project, Pritzker said 40 percent of the residents have some type of affiliation with the university, either as faculty, staff or alums. The Hyatt project includes an auditorium where lectures will be held. "Whatever the residents tell us they want, we will make it happen," said Pritzker, who added that similar programming ideas are being implemented at other Hyatt retirement developments.

New college-based projects also follow other housing trends. Apartments tend to be larger than they were in older projects. Buildings have more amenities, such as swimming pools and health services. "Developers are getting more intelligent about these developments," Brod said.

Despite a few press reports that not all students want retirees in class, expect more campus developments. The country has about 3,000 private colleges and universities, Brod said. Only about 90 campuses either have or have considered a retirement project. "There's plenty of room to grow."