Some teenagers might consider Lisa Moris's college room the lap of luxury. She has free cable television, central air conditioning, a private bathroom and daily maid service.

But Moris and her roommate, both freshmen at Boston University, also share a single closet more suited to an overnight stay than an academic semester. They must keep their door closed at all times, and they have no dining hall or laundry facility in their building.

Theirs is the latest in dormitory living in rental-space squeezed Boston: the Howard Johnson in Kenmore Square. "Basically, they have no room for us anywhere else, so we got stuck with this," said Moris, 18, a psychology major whose roommate hung Marilyn Manson posters on a wall opposite the generic hotel pastel prints framed above their beds.

Pinched by one of the tightest real estate markets in Boston's history and increased college enrollments, the nation's higher education capital is packing students into almost every conceivable space. And there is no short-term solution to the bed shortage in sight.

Under mounting pressure from residents and Boston Mayor Thomas M. Menino to keep students on campus, several universities and colleges are building large-scale dormitories here for the first time in decades--a fix that comes too late for most current students.

Single rooms have been turned into doubles, doubles into triples and triples into quads everywhere from Brandeis University in Waltham to the Massachusetts Institute of Technology in Cambridge, which sent letters to parents warning about possible crowding. At least until January, Boston University is housing about 400 students in the Howard Johnson here and in Cambridge, with an additional 225 students bunked at a small, Catholic women's college nearby.

Boston College purchased loft-style furniture and rushed in carpenters over the summer to transform dormitory lounges into bedrooms, while Northeastern University placed 81 students in single rooms at the YMCA. Meanwhile, the University of Massachusetts at Amherst assigned 100 students to a campus hotel and asked 200 undergraduates to stay home last week until officials determine exactly how many rooms will be available.

The housing shortage on and off campus is so severe, college officials said, that several graduate students who could not find affordable apartments decided to defer their study plans for another year. "It certainly is tight," said Sarah Bingham, a staff assistant at Harvard University's undergraduate housing office. "And people are desperate."

Colleges nationwide have experienced similar situations, forcing them to temporarily place students in hotel rooms or even on cots in their gyms. Catholic University, for example, experienced a big enrollment increase this year and bought 25 trailers from a New England college. Each of these modular units will house four students until the university can build another dormitory.

But with more than 60 institutions of higher learning in the greater Boston area, and 32 colleges and universities in the city alone, the arrival of tens of thousands of students every September feels less like a congenial homecoming than a communitywide invasion of U-Haul tanks and backpack-toting troops. For instance, two of the largest schools--Boston University and Northeastern University--have a combined total of more than 27,000 undergraduate students but fewer than 15,000 beds.

This year's onslaught is particularly oppressive given Boston's vacancy rate for rental property of less than 2 percent and rents that in some cases have quadrupled following the demise of rent control in 1994, according to city officials. Moreover, an increasing number of young professionals are staying downtown, while suburbanites are moving back in, said Tom Philbin, spokesman for the city's Department of Neighborhood Development.

That leaves little room for sophomores, juniors and seniors who counted on moving off campus and finding inexpensive housing in neighborhoods with traditionally dense populations of students, such as Allston and Brighton. (Freshmen are generally guaranteed housing.) City statistics show that two-bedroom apartments are fetching an average of $1,450 a month, up 75 percent from five years ago. As a result, the number of juniors and seniors wanting to stay on campus at Boston College rose 14 percent this year, and Boston University has a waiting list of several hundred people whose plans for off-campus living fell through.

"Affordable housing just gets tougher and tougher. Every year, there are times when I wonder where people end up," said Al Norton, general manager of Matching Roommates, billed as the nation's oldest roommate service. "The way it is now, there aren't many cheap areas in Boston anymore."

Jack Dunn, a Boston College spokesman, agreed: "The reality is that the colleges have got to find ways to work with the communities because this is a problem that's not going to go away.'

Relief may be coming with the promise of new construction and pledges by universities and colleges to house more of their students on campus. Harvard and MIT have announced plans to open new residences, and Boston University, which built its last dormitory in the 1960s, is building an $80 million dormitory with 817 beds overlooking the Charles River.

The ranks of the fortunate already are visible atop Northeastern's newly opened high-rise towers, whose corner suites overlook the historic Boston skyline and distant harbor islands. Lucky students such as Stacy Musone, 19, a sophomore, are paying roughly $2,000 a quarter for one of 600 beds in spacious units with dishwashers, individual bedroom thermostats, central air conditioning and private baths.

Two more Northeastern dormitories with a total of 1,000 beds are scheduled to open next year, and officials say that will reverse a two-year trend of turning away students who want to live on campus and could provide valuable rental income should the economy take a downturn and enrollments fall.

Musone, for one, said she could not believe her good fortune as she lugged a duvet into her new home. She spent last year in a cramped triple designed for two. Now she has whitewashed walls and a view of the Museum of Fine Arts. "There's no roaches here," she said. "It's beautiful."

CAPTION: Boston University put freshmen Joanna Janczurewicz, left, and Lisa Moris up at the Kenmore Square Howard Johnson.