Tom Whittaker and his three roommates, like many other George Mason University students, are saving money by sharing a four-bedroom brick house on a quiet tree-lined street in Fairfax City, only a few blocks from campus.

But the Fairfax City Council, faced with numerous complaints about off-campus disturbances among students in group houses, soon may try to alter the collegiate life style.

A proposed change in zoning regulations would reduce from four to three the number of unrelated persons allowed to live under one roof.

The proposal would affect the large number of students who live in subdivisions scattered around the city and must share living quarters because of high rent for houses and apartments and costlier housing on campus.

The City Council will hold a public hearing at 8 p.m. Tuesday on the proposed change, which is opposed by the city's planning commission.

Peggy Wagner, the city planning director, said housing violations and noise complaints should be handled under existing laws through stepped-up enforcement by the city zoning office and the police.

Whittaker said sharing his $640-a-month rent with two other people instead of three would be "unmanageable" and would force him either to get a job or find less-expensive housing.

"It's a lot cheaper to live off campus," Whittaker, 20, added. "One of my roommates is going through school on grants and scholarships, and he'd be in serious trouble if he had to move."

The university charges $2,400 a year for a dormitory room, about $1,000 more than Whittaker pays for off-campus housing.

But neighbors on Whittaker's street say they have little sympathy for the students.

"This neighborhood is slowly being eroded into residential housing for George Mason University," said Richard Turney, who lives near several student group houses.

Other residents in Turney's area have complained to the police department about late-night weekend parties that resulted in fights, vandalism, littering, drunkenness and noise.

But another George Mason student, who did not want to be identified, said his three housemates are no noisier than the family across the street.

"The teen-age girls there have friends over all the time and we never complain," said the 24-year-old senior, who works as a maintenance man during the day. "The families around here have to accept us as a fact of life. What else are people in our financial situation supposed to do about a place to live?"

Donald J. Mash, university vice president for student affairs, said that students are not the sole source of neighborhood disturbances. Mash said the university encourages its students to live in owner-occupied homes with families throughout the city.

Some other people who live in communal houses, such as single professionals and unmarried couples with young children, draw disturbance complaints, noted council member Robert F. Lederer Jr.

"The university is a very positive part of Fairfax City," Lederer said. "It's basically a quality-of-life issue for the residential neighborhoods here. It's a matter of the city taking control of its own destiny in determining where you can or can't allow that type of housing."

Prince George's County, where about 35,000 students attend the University of Maryland in College Park, and Montgomery County permit five unrelated persons to live in the same house.

Fairfax and Arlington counties and the City of Alexandria permit four unrelated persons to live under the same roof, and the District of Columbia, six.