Can bringing young and old under one roof solve the world's housing crisis?

Home sharing initiatives that link cash-strapped young people with elderly home owners are becoming popular with governments around the world as they seek to tackle the twin crises of homelessness and loneliness, experts said on Thursday.

Home sharing, which usually involves an older person offering a spare room at low cost to a young person in exchange for help and companionship, is increasingly seen as a solution to the problem of affordability faced by many countries.

Experiments in a number of countries suggest it could also alleviate loneliness among older people - a growing problem as populations age and more and more people live alone.

"In this city, home sharing is gaining momentum," Celine Fremault, housing minister for Brussels, told an international symposium in the Belgian capital. "We want to promote a well-proven model."

She said the Brussels government would support such initiatives, with projects already under way to create 350 new inter-generational homes as part of the city's public housing policies.

Inter-generational home sharing among strangers likely began in the 1970s in the United States, according to Homeshare International, which hosted the World Homeshare Congress.

The concept spread to Europe in the 1990s and later to Australia, and there are now a growing number of pilot projects in Asia.

Baudouin Waulquez, an 86-year-old Brussels resident who took a young musician into his home, said living with someone from another generation had been an "extraordinary experience".

He said living with a 19-year-old had required some adjustment - including learning to share the fridge - but he was pleased he could accommodate someone who would otherwise struggle to live in the city.

"The match was really perfect and took off immediately," he said.

Open to the world

Kirby Dunn, executive director of Homeshare Vermont, said the non-profit received about half its funding from state.

"I think smart governments look at this as a very cost-effective way to save money but they don't want to do it alone."

Inter-generational home sharing has steadily gained ground in cities from London to Seoul, as property prices rise and traditional family structures change with more and more young people moving away from their families to take up jobs.

Population ageing is set to become one of the most significant social transformations of the twenty-first century, according to the United Nations - with the number of people aged 60 or over to more than double by 2050.

Loneliness is a particular problem for older adults and research links it to dementia and premature death.

In Britain, the majority of people over 75 live alone and about 200,000 older people have not had a conversation with a friend or relative in more than a month, according to government data.

Annie Boisdenghien, 76, became a host in Brussels after seeing a newspaper advert for home sharing a decade ago, and has welcomed students from Ireland to Poland.

"My nest was empty," she told the Thomson Reuters Foundation. "Now, I am not alone, there is life in the house."

Boisdenghien enjoyed attending concerts with her young flatmates, who have made her feel physically secure and happy, she said.

"When you live alone in a big house, you sometimes feel lonely, so to fill the vacuum you turn to other people."

Her current housemate, Mattias Renaux, 21, is a communications student in Brussels and enjoys baking pastries for Boisdenghien.

"We do complement one another and we enjoy our lives," he said.

With two-thirds of people set to live in cities by 2050, according to the United Nations, and property prices climbing, delegates said that could soon become the social norm - with advantages for both sides.

"I want to remain open to the world," said Boisdenghien. "I don't want to stick to the old ideas."