Love & Money is a MarketWatch series looking at how issues surrounding money impact our relationships with significant others, friends and family.

Married couples are making room for roommates.

Sometimes, multiple roommates. Just ask Kelsey Riley Dixon. The 29-year-old business owner and her husband, a semi-pro kayaker, share a four-bedroom home with three male roommates “to reduce costs in the very expensive city of Seattle,” she says. “It allows us to have a home in a really expensive city with a deck, a backyard, a basement — and we are able to pay half the rate that we would living on our own.”

“ Stephanie, a 28-year-old PR professional, was only able to afford to move to San Francisco in 2017 because a married couple offered her a rent-controlled room in their apartment. ”

One big motivation for having roommates: Having extra money to travel. The couple recently spent nine months in Chile, Peru, Australia and New Zealand. “We don’t want to spend that much money on rent. This [having roommates] aligns with our values. We’d rather use that money for travel,” she says. And she adds that not only does having roommates help financially, it’s also “fun and rewarding.”

They’re part of a growing trend: The number of married couples living with roommates has doubled since 1995, according to a recent report from real estate site Trulia. About 280,000 married people now live with a roommate — and that’s particularly true in pricey cities like those on the West Coast.

The reason: Housing costs a ton. In Honolulu and Orange Country, Calif., the share of married couples with roommates is between four and five times the national rate. San Francisco, Los Angeles, San Diego and Seattle also have sky high rates of married couples with roomies. Those same cities all have well above average rental and housing costs (Trulia notes that housing costs in all these markets have risen more than 30% since 2009), with residents of uber-pricey San Francisco requiring more than $123,000 in income to live comfortably, one study showed.

“While only a small share of married couples live with non-family members, the ones that do often take on roommates either as a financial strategy to cope with housing costs or as a means of assisting others burdened by housing costs,” Trulia reports.

Logan Allec, a 30-year-old Santa Clarita, Calif., resident, and his wife had a roommate when they first got married. “We had an extra bedroom upstairs with its own bathroom and a little living area and we charged $850 a month,” he explains. “We were in our 20s and that was a nice chunk of change.”

But pretty soon Allec’s wife wanted more privacy for their budding marriage. “About a year ago, our roommate took a job some 50 miles away and moved out — and my wife couldn’t have been happier,” Allec jokes. And now that the couple is expecting a baby, getting another roommate is off the table, even though Allec, a CPA at Money Done Right, loves getting the extra money from renting. “A new roommate plus a new baby would be a little much,” he says.

But that situation happens too. Stephanie, a 28-year-old PR professional who asked that we withhold her last name, was only able to afford to move to San Francisco in 2017 because a married couple offered her a rent-controlled room in their apartment. And thanks to that great deal, she’s still living there today — even though the couple now has a 6-month-old baby who sleeps in the room next to hers. “It’s a great 3 a.m. alarm,” she jokes of the middle-of-the-night crying.

Even so, she’s likely staying put, because not only does she like the couple, she says she’s unlikely to find anything else affordable. “There are so few options that are less than $2,000 a person and I am still trying to pay off student loans.”

Of course, problems can arise when singles move in with a married couple. Thirty-four-year-old Ashley Patrickrecalls the time that she and her husband rented out their upstairs room to a friend so they could afford their house payments during a tough time financially. The roommate — who they loved — sometimes did things they didn’t love. “He would pee in the middle of the night but wouldn’t turn the light on so he’d get pee on the bathroom floor,” Patrick recalls. “We were living with a bachelor and he was a mess.”

Still, she says, they loved his sense of humor, and ultimately are glad they had the roommate, as it helped them afford to keep their home. “We were both starting out in our careers, and that [having a roommate] helped us get through those [financially tough] beginnings,” she says.

If you’re single and thinking of either moving in with a married couple or vice versa, keep a few things in mind. Elizabeth Lombardo, psychologist and author of “Better Than Perfect: 7 Strategies to Crush Your Inner Critic and Create a Life You Love,” says it’s essential in this potentially fraught situation to set ground rules that you all agree on (Dixon, her husband, and their roommates all have a chore wheel that dictates who does what when) and keep the communication open. Finally, “Look for ways to make things work. Don’t keep score. Taking steps to make things easier for your roommate, partner and you will make things much smoother,” she adds.