TORONTO -- After her husband died, Elizabeth Hill says she would lay awake listening for bumps in the night in her eerily empty home -- so to get some shut-eye, she decided let a stranger live with her.

Since then, the 75-year-old has compiled seven "guest books" filled with photos and thank-you notes from the dozens of young international students who have stayed with her over the past two decades.

Hill is one of a number seniors who have been moving in with students in exchange for subsidized rent and occasional help around the house -- often with the added benefit of lasting friendships.

A Toronto elder-care initiative is working to replicate these mutually beneficial living arrangements this fall, in a provincially funded pilot project that aims to set the Canadian standard in intergenerational home sharing.

Researchers say these shared-living programs could help address two of Canada's most pressing social issues: housing affordability and caring for an aging population.

But Hill and 32-year-old Julio Hernandez, who have lived together for seven years, say the benefits can go far beyond reduced living costs, because the care goes both ways.

"At this point, I see her more like a friend than my landlady," Hernandez said. "She's like my Toronto family."

As baby boomers and millennials alike get priced out of red-hot housing markets, schools and community groups across the country have embraced various kinds of shared-living programs -- from a housing co-op in Winnipeg where women can grow old together, to a retirement home in London, Ont., that hosts Western University students.

In Ontario, more than half of residents -- and three-quarters of those over the age of 65 -- live in houses that are bigger than they need, leaving five-million spare bedrooms across the province, according to a 2017 report by the Canadian Centre for Economic Analysis.

That means many seniors have more space than they can afford, while students struggle to pay rent for cramped living quarters, said Raza Mirza, a University of Toronto researcher with the National Initiative for the Care of the Elderly.

The financial stress is exacerbated by growing costs and wait lists for long-term elder care or assisted living, Mirza said, while students face mounting tuitions.

With the Toronto Homeshare Pilot Project, Mirza and a group of researchers, social workers and government officials hope to find symbiotic solutions to these pressures so that seniors can stay in theirs homes, while students find new ones.

By Sept. 1, the four-month program is expected to match up as many as 20 pairs of senior-student roommates through a rigorous screening process. Participants will be asked to sign agreements that can require young boarders to commit up to seven hours per week to running errands or spending quality time with their hosts.

Researchers hope the insights they glean from the pilot project and subsequent studies will eventually be used to develop a home-sharing model that can be tailored to cities across the country.

But as they work out the kinks at this early stage, they're counting on Hill and other seniors who shared their success stories at a recent information session to guide them.

Joyce Rainville, 69, has been on both sides of the home-sharing equation. In her 20s, Rainville said she moved in with a family in Guatemala, and despite not speaking Spanish, forged a relationship that would stick with her long after she returned to Canada.

In the past 14 years, Rainville professes to have taken in "hundreds" of students, sometimes as many as four at a time. She helps them practice their English, and in return, they often introduce her to customs and cuisines from their home countries.

"I always said when I can do it, I'll give back," Rainville said in an interview. "They were away from home, and my home was their home."

When Hernandez arrived on Hill's doorstep from Cuba in 2011, they agreed he could stay in her west-end Toronto home for a six-month trial period as he set out to earn his master's degree.

Last Friday, the two of them decided to get out of the house and go to a restaurant to celebrate his successful defence of his doctoral thesis, which lists Hill in the acknowledgments.

Hernandez said he wanted to pick up the cheque to thank Hill for any number of things -- reducing his rent so he could make ends meet during his studies, comforting him through a breakup, or having supported his brother the same way when he lived with her years earlier.

"She was always there for me," Hernandez said. "She was essential for me to get to this point in my life."

Hill wouldn't have it. Lunch was on her.

When Hill is feeling down, she flips through her guest books and looks back on all of the memories she's shared with her unlikely roommates over the years.

There was the look on her first guest's face when she showed him his room with a double bed and he asked, "Is this all mine?" And the student who massaged her back as they watched the sunset on Toronto Island.

Of course, she sometimes had to deal with wet towels on the bathroom floor, or wait up until 11 p.m. to make sure a young woman got home safe from her night on the town.

But 95 per cent of her experiences have been positive, Hill said. So she can put up with the little things, because she gets so much in return.

And besides, she noted, "I'm not their mother."

But that doesn't mean she isn't family.