After separating from her husband in 2007, Katie Marcoux and her two young daughters moved in with her parents for financial reasons. She expected to stay a year at most.

Thirteen years later, Marcoux -- now remarried -- still lives in the house, along with her parents and one of her daughters.

Such arrangements are increasingly common in the US, where one in five people now live in a "multigenerational" household, according to Pew Research Center.

The phenomenon has been on the rise since the 1980s, when immigrant families arriving from Asia and Latin America tended to reside in households that ran the gamut in the age of residents.

There was another rise starting around 2009 when the Great Recession brought the number of adults living in their childhood homes back to levels last seen in the 1950s.

Now, with the upheaval of COVID-19, many are turning to the playbook again.

New directions

When she moved in, Marcoux, now 49, was working part-time for the school system and "not in a very good financial position," she recalled.

But living with her parents allowed Marcoux to maintain a part-time work schedule while raising her daughters, who were adjusting to new schools and their parents' divorce.

She was assisted by mother Judy Kristensen.

"When the girls were little, we were able to help Katie out by driving them places and stuff so she could work," Kristensen, 78, said.

Meanwhile, Marcoux was able to progress professionally and now works full time.

"One of the things that it has afforded me big time is a financial freedom that I was able to recover," said Marcoux.

Eric Marcoux, husband to Katie, felt "very at home" with his in-laws, "so I sold my house and moved in," recalled the 47-year-old former cartographer, who brought his dog, Jazzman.

Still, Marcoux, his wife and two stepdaughters, then teenagers, were forced to share one bathroom, an arrangement that "wasn't ideal," he said.

The situation improved immeasurably after a home improvement project added a second master bedroom and another bathroom.

Dana Scanlon, a real estate agent in the Washington region, said more young parents are taking a similar approach during the pandemic.

"We have seen many couples with young children move in with their parents, into the large homes they grew up in -- something they never imagined they would do," Scanlon said.

"This allows them the opportunity to have in-house babysitters or 'Zoom school supervisors' while they work from their laptops."

Golden years

Another factor behind the shift has been the aging of the overall population, with many baby boomers still vigorous but looking ahead to a future when mobility will probably be more difficult.

Marcoux's parents appreciate the buzz of company when many of their contemporaries rue their solitude and they don't expect to have an empty nest again.

Staying with the parents is "definitely our plan," Marcoux said.

"When we did the modifications to the house, we also redid their bathrooms so that it was more accessible for elderly."

Marcoux has two older brothers in the area, "but it is just kind of an understanding that I will take care of them," she said.

Marcoux's youngest daughter, Jenna, 19, moved to New York for college, but Eva, 20, is living in the home as she studies graphic design.

"It really benefits me because at the end of the day I have a really strong support system," Eva said.

The arrangement has also worked well for grandfather Dano, 80.

"We have a very close relationship with all of our grandchildren," he said. "But it's special when they live with you."

Richard Fry, a senior researcher at Pew Research Center, said there has been a "sharp rise" over the last decade in young adults living in multigenerational households.

In 2016, the number of 25-29 year-olds living in such homes rose to 33 percent from 23 percent nine years earlier.

A common challenge for millennials and other young Americans has been the burden of student loans.

"Clearly what this reflects is that there's a segment of young adults who are simply having trouble earning enough to be able to live independently," Fry said.