On Thursday, Cabot, Cabot and Forbes, with financial backing from Chicago-based investment firm Blue Vista Capital Partners, paid $21 million to buy the property along Washington Street from Steward Health Care System, which owns St. Elizabeth's. By mid-year they aim to file a proposal with the city to renovate the existing monastery and add buildings on the site of an existing parking lot. The project could include about 400 to 500 apartments aimed at grad students, at rents those students can afford, said Cabot chief executive Jay Doherty

A veteran local real estate firm is teaming up with one of the biggest student-housing developers in the country to turn the 12-acre site next to St. Elizabeth's Hospital into a complex of buildings aimed at a booming but underserved population of 20-somethings.

The site of the old St. Gabriel's Monastery in Brighton could be the start of a new trend in the Boston housing market: privately run apartments for graduate students.

"The idea is to provide a housing option that gives an inducement for graduate students to live there and get out of the way of families trying to live in the three-deckers of the neighborhood," Doherty said.


Graduate student housing has become a factor in Boston's housing squeeze. The population of graduate students has increased by nearly 50 percent since 1994, to more than 48,000, according to city data. Most live off-campus, many squeezing into apartments that could otherwise be rented to working families. In Allston/Brighton alone, an estimated 3,600 graduate students live off-campus, enough to have a measurable impact on the rental housing market, experts say.

The Walsh administration has a goal adding 53,000 units of housing to the city by 2030 and has been pushing universities to contribute, especially for undergraduate students. So far there are 1,200 dorm rooms under construction, according to city figures. Late last month, Northeastern University and private developer American Campus Communities filed plans for an 800-room dorm in Roxbury.


But housing for graduate students has been harder to come by.

Enter private developers. Investors have poured into the student-housing market in recent years, financing nearly 7,000 student apartments nationwide in 2014, according to real estate firm Colliers.

Students like the high-quality amenities these new buildings can offer, and investors like the reliable rents that students bring, said Dorothy Jackman, managing director of Student Housing Services at Colliers.

"There's no shortage of developers looking for these opportunities," she said.

But those developers have yet to find many opportunities in Boston.

Expensive land and lengthy development times have made private student housing rare here, despite the huge student population. Just one large dorm — Northeastern University's new $75 million GrandMarc Hall for undergraduate students — has been privately financed. The American Campus project at Northeastern and St. Gabriel's are poised to be next.

Several private developers have been in talks with local universities, Boston housing chief Sheila Dillon said recently, with Suffolk University one of several schools studying the idea of an off-campus "student village."

The St. Gabriel's complex would not be attached to any particular university, Doherty said, but rather aimed at grad students citywide. Located along the Green Line, the Brighton location is between the main campuses of Boston University and Boston College.

Peak Campus Development, an affiliate of Blue Vista and the nation's second-biggest student housing developer, would market and manage it. It's developing similar complexes in Chicago and Charlottesville, Va., and sees a huge opportunity in Boston, president Jeff Githens said.


Peak Campus Development is developing similar complexes in Chicago.

"Just the sheer number of grad students at universities in Boston — it's so sizable," he said. "And we'll be filling a need that's largely unmet by new apartments today."

Aside from the renovated monastery, Doherty said, the buildings will probably look like other apartments going up around the city: five stories tall with wood frame construction. Inside, though, the units will be smaller, with more common space in the building for studying and amenities such as a 24-hour gym and in-building Wi-Fi. There will likely be fewer than one parking space per unit and perhaps shuttles to nearby universities, Harvard Square, and Longwood Medical Area.

Doherty said his company will try to set rents significantly lower than many "luxury" apartment buildings that have recently opened in Boston, where two-bedrooms can start as high as $4,000 a month even in outlying neighborhoods such as Jamaica Plain.

"We'll be materially lower than that," Doherty said. "We're breaking a little bit of new ground."

Doherty said he's been talking with local labor unions about ways to potentially lower construction costs for the project. He said he has also reached out to Secretary of State Bill Galvin, a Brighton resident whose support would be essential for possible tax credits on historic properties that Doherty hopes can subsidize the rehab of the century-old monastery.


Galvin's office did not return a message seeking comment Monday.

And while the deal to purchase the land just closed Thursday, Doherty said he has begun reaching out to neighborhood groups to seek their support.

"We want to make sure we get all our ducks in a row with the neighborhood and local leaders," he said.

Other big student-housing developers will be watching, Jackman said. And if the St. Gabriel's project can work, she predicted, it won't the last.

"There's demand and there are many developers who would be happy to be engaged there," she said. "If there's a way to get it done in Boston, they'll get it done."

A developer seeks to build about 500 units at the monastery and on adjacent land. Joanne Rathe

Tim Logan can be reached at tim.logan@globe.com. Follow him on Twitter @bytimlogan.