Community College of Philadelphia plans a pair of new residential towers beside its Spring Garden Street campus to accommodate a hoped-for influx of high-achieving - and higher-paying - international students.

The two-year public college has selected Wayne-based Radnor Property Group to develop the roughly 500-unit, 11-story complex at 15th and Hamilton Streets, with plans for a mix of student and nonstudent housing.

CCP joins a small but growing list of community colleges nationwide that are looking abroad for an antidote to sinking enrollments. Key to their plans are on- and near-campus housing for the newcomers, a shift for what historically have been commuter schools.

"You can't realistically recruit international students without housing," college president Donald Generals said. "I think we are grossly underserving that market, and I think that is a growing market."

School trustees voted Thursday to enter exclusive negotiations with Radnor after vetting multiple proposals for the 1.7-acre school-owned site that is now an industrial building and garage. The deal would have Radnor enter a long-term ground lease for the land and agree to rent a portion of the complex's units to CCP students.

Work on the $130 million project, which will include ground-floor retail and some underground parking, could begin in spring of 2017, with the first tower complete for the 2018 school year, Radnor president David Yaeger said.

It will be the first major construction project at CCP's main campus since a $56 million expansion of the school's academic and administrative buildings that began in 2008.

"We see this as just a phenomenal opportunity, particularly as the Community College is entering a different phase with this residential-life program," said Yaeger, whose company is also developing a residential tower on Drexel University-owned land. "It's incredibly thrilling."

While CCP's student-designated housing will be available to all enrollees, the need to accommodate scholars from abroad was central to its planning for the site, Generals said.

Only about a quarter of community colleges offered housing during the 2011-12 year, the most recent period for which American Association of Community Colleges data on the topic were available.

But the number seems to be growing, as schools use dorms and apartments to draw overseas students looking for cheaper alternatives to four years at a full university.

Green River College in Auburn, Wash., about 20 miles south of Seattle, sets aside half of the 330-bed residential complex it built about 10 years ago for foreign enrollees, said Emilee Findley, a housing specialist at the school's international program.

The dorms at California's Sierra College, meanwhile, give that school in a rural region northeast of Sacramento an advantage over similar institutions in coastal areas, said international programs manager Alistair Turner. Foreign students make up just 1 percent of the college's 20,000 enrollees, but they occupy about a quarter of the dorm rooms at its main campus in Rocklin, he said.

"Many community colleges in California don't offer that," Turner said.

CCP is turning its gaze abroad as it seeks to reverse a 15 percent drop in enrollment to about 32,200 for the 2014-15 school year, down from around 38,100 when the student body last peaked, in 2009-10.

The decline - echoed in community college enrollment figures nationwide - comes amid an improving economy that is reducing demand for continuing education, as well as growing competition from for-profit operators such as the University of Phoenix, Generals said.

As a first step toward boosting its international head count - now at just over 200 - CCP has contracted with Washington, D.C.-based Quad Learning Inc. to recruit about 300 overseas students during the next five years, Generals said.

Quad Learning's program places international students with good grades in community colleges, with later transfers into four-year U.S. universities guaranteed if certain criteria are met.

The influx of high-achieving international students "will lift the overall quality of the institution," Generals said.

It will also lift revenue: Program participants pay three times as much as locally based CCP students, though Quad Learning takes a cut of the tuition, he said.

Through the program, Generals expects to easily attract overseas students seeking spots at Philadelphia's dense concentration of high-quality universities, as well as those drawn by the city's recent designation as a World Heritage City.

"The reason that we could not be more aggressive in recruiting international students is because we didn't have housing," he said. "Now that we will have it, we'll be more aggressive."