The empty nests are starting to feel a bit full.

Young adults are returning to their parents’ homes with plans to stay for a few weeks, a few months or an undefined period with an ever-rolling end date. Many have been back in their childhood bedrooms for months: A Pew Research Center survey found that more than half of people between the ages of 18 and 29 were living with their parents in July. That figure was higher than at any time since the Great Depression.

“It doesn’t necessarily mean they’re taking a step back or putting their lives on pause,” said Daniela Domínguez, an assistant professor at the University of San Francisco and a practicing psychologist. “It might be financially more responsible.”

And with the holiday season in full swing, even those who are not moving in might be home for longer than usual because of health concerns, in deference to logistics, or because working remotely makes it possible.

For those who have tasted independence — or have had independence but need a bit of coddling after months of living through a pandemic — moving in with family, even temporarily, can be tricky. Believe it or not, parents, too, have their own lives and may struggle with adapting. You’re not their center of gravity anymore.

“Children and parents need to give each other space,” said Deborah Carr, a sociology professor at Boston University. “Who they are now is not who they were 10 years ago.”

Renegotiating established relationship patterns and expectations can be a challenge. “It’s not just that the kids are living with their parents,” Dr. Carr said. “It’s also that we’re collectively living in this pressure cooker of stress.”

And returning home can revive habits people thought they left in their teenage years, like lashing out at their parents or letting them do all the laundry. When that happens, Dr. Domínguez said, it’s important to remember: “We’re adults living with adults having adult relationships.” Here’s how to act like one, from move-in to move-out.

Step 1

Before you move in, consider when and how you will move out. “Thinking about the future beyond the virus is good for everyone’s health and the family’s well-being,” said Tama Leventhal, a professor of child study and human development at Tufts University.

If you moved in with your parents for financial reasons, think about ways you can readjust your lifestyle once you’re ready to return to the hustle and bustle of independent life. Then start saving that cash.

If you can work remotely, think about living somewhere where rent and other expenses are cheaper.

Step 2

If you want to live your life the way you have been — whether that means seeing friends, dating or indulging in long stretches of alone time — you should negotiate those needs ahead of time.

And when it comes to Covid-19 safety, always defer to the highest risk family member. “Everybody needs to get their act together and make sure that they’re not the potential person bringing danger into the household,” Dr. Carr said. “If one person gets sick, chances are everybody is going down.”

Once you have assessed your needs, share them. “Discuss class and work schedules, the division of household labor, the importance of personal space, use of common areas, and expectations about guests sleeping over,” Dr. Domínguez said.

But keep in mind that this is not a “fixed contract,” she added.

If you don’t think you can keep your family safe and meet your personal needs at the same time, you should probably stop reading this right now, and consider rooming with people who are not your parents. ¯\_(ツ)_/¯

Step 3

OK, so you’ve decided to move in. If you have an income, offer to pay for some portion of the rent or mortgage, for part or all of the utilities or for groceries. If those are not viable options, look for more creative gaps to fill.

“Ask, ‘can I buy Friday night’s dinner?” said Ashley Dixon, the lead planner at Gen Y Planning, a financial planning firm. Buy that Costa Rican coffee your mom raved about or the cabernet sauvignon your dad only drinks on special occasions.

If helping out financially is not within reach, or too awkward to offer, volunteer your labor: wash the dishes, walk the dog, cook dinner, vacuum the floors or mow the lawn.

If your parents refuse all your offers, take those extra dollars and give them to someone in need in your community.

Step 4

Just because you are on the Keto diet now does not mean you get to empty the fridge of Ben & Jerry’s and harangue your parents every time they eat pasta. Unless your family members express interest in one of your undertakings, let them live.

But if they do want to talk about setting mutual goals, go for it. When Dr. Domínguez temporarily moved in with her mother in Mexico this year, the two of them talked about eating healthily and exercising regularly. They made daily plans to reach those targets together.

“Everyone’s physical and emotional health within that family system is closely linked,” Dr. Domínguez said.

Step 5

“Every family has their own culture,” Dr. Domínguez said. “Stop, think and listen,” Dr. Leventhal said.

For example, if you want to spend the night at a “friend’s place,” it may feel awkward to even begin that conversation. First, find out what your family thinks is acceptable in terms of exposure to Covid-19. “Would they feel comfortable with you going on a socially distanced date?” Dr. Domínguez said.

Once those boundaries have been established, be respectful. If you are heightening their exposure to Covid-19, you need to be transparent about that.

Step 6

Some families have a higher tolerance for conflict; others avoid confrontation at all costs. Things are going to get heated. Before you lash out, walk away and do whatever you need to do to stay calm. That could be a walk, a yoga class, a meditation. (If you’re new to it, try this.)

“Re-enter the conversation when there is less heightened emotional activity,” said Jacqueline Hudak, a family therapist in Philadelphia.

And be patient. Remember, Dr. Hudak said, “relational change takes time.”

Step 7

Plan a game night! Decorate holiday wreaths! Use some of the money you are saving to watch “Mariah Carey’s Magical Christmas Special”! Have fun.