SANTA CRUZ — Jonathan Giffard, a freshman at UC Santa Cruz, lives on campus this year. But next year, he’ll probably join thousands of sophomores, juniors and seniors who rent in city neighborhoods — a phenomenon that makes homes more expensive to rent and buy for other residents.

Finding affordable housing is a challenge not only for students, but also for newly hired faculty members because the median selling price for a single-family home in Santa Cruz County is $600,000.

As campus administrators study the feasibility of boosting enrollment from 15,000 to 21,000 students by 2020, city officials are considering a creative new idea for housing downtown.

The proposal, presented to campus officials at a public forum last week, involves building another parking garage downtown, then putting multi-story buildings with first-floor retail shops on parking lots owned by the city parking district.

Building smaller living units could reduce the demand on single-family homes, opening them up to families with children, said city planner Laura Spidell, displaying a drawing of what a multi-use building at Cedar and Lincoln streets might look like.

The project could happen in four or five years, or sooner, if the city moved it higher on the priority list. The first step, Spidell said, is to find financing to build the parking garage. Another key step would be relocating the popular downtown farmers market held Wednesdays.

Only three dozen people heard the presentation, but the reaction so far has been mostly positive.

Giffard, who is on the campus transportation advisory committee, liked the idea.

So did most of the upperclassmen in the room. After freshman year, they said, students are ready to live on their own rather than have a dorm supervisor looking over their shoulder.

They want a living arrangement that costs less than on-campus options and lets them skip the meal plan they claim doesn’t cater to vegans and vegetarians. When three or four students rent off-campus, they can split the costs and cook for themselves.

"Why live on campus?" asked Nathan Luedke, a junior. "It’s abnormal."

Faculty members like psychology professor Faye Crosby are enthusiastic about the downtown housing concept.

"I thought the picture was gorgeous," Crosby said. "It sounded like people were really thinking ahead. The city should get a lot of credit."

Dr. Scott Daly, an optometrist with a downtown office, said the idea would be attractive as long as the parking garage provided enough spaces.

"Desperately, we need more parking downtown," he said.

UCSC houses about 50 percent of its students on campus. That has been a source of friction with the community because the 1988 long-range plan had a goal of housing 70 percent of undergraduate students on campus.

City residents contend that if more students lived on campus, there would be less traffic on city streets. Some suggest offering incentives to encourage students to stay on campus.

However, campus officials say the 70 percent goal may be unrealistic for students nowadays.

"Our market analysis shows the demand is for about 50 percent of the students," said Jean Marie Scott, who oversees campus housing. "At other schools, it’s 35 percent."

Freshmen comprise the vast majority of the students living on campus. At UCSC, only 3 percent opt to live off campus their first year.

Tom Vani, the campus vice chancellor for business, said he has seen the change in attitudes between an 18-year-old freshman and a 20-year-old junior at other universities.

"Students change majors, colleges, roommates," he said. "We’ll set aside land to house 70 percent of our students if needed, but the market may say it’s not needed."

City resident Lynn Robinson, founder of a neighborhood group working on issues such as traffic, said she is not surprised by student interest in living off campus.

"It’s not a ‘City on the Hill,’ " she said. "The choices are limited."

She suggested campus officials review housing policies that have unintended consequences in neighborhoods.

The meal-plan policy is one example. Another is the rule prohibiting freshmen and sophomores from having cars on campus, which Robinson says results in students parking their cars in neighborhood streets.

"The spirit of the policy is good, but the reality of how it affects our town is another story," she said.

Giffard, a student representative on the campus transportation committee, said he has discovered that more buses are needed to accommodate students and that faculty commute because of the shortage of on-campus housing.

He contends that data show student drivers comprise a small portion of traffic on city streets.

"People have to come to grips with the fact that the city is 95 percent of the traffic," he said.