Stephanie Pellicano, 30, spent the better part of the pandemic trying to convince her sister, Jacqueline Pellicano, 32, to get an apartment in her building, a luxury rental along the Jersey City waterfront.

The younger Ms. Pellicano, worried that her sister’s living arrangement — with a roommate in another Jersey City building where other tenants did not seem to follow social distancing practices — was risky for their family. It would be better, she thought, if they were all together.

Jacqueline Pellicano resisted until last October, after her roommate contracted Covid-19 and she subsequently spent three weeks sleeping on her younger sister’s sofa. “But it worked. It just made life easier,” she said. “It was so nice to all be together and it kind of solidified it. OK yes, I do want to be here.”

By November, she was living in a studio at the Vantage, a two-tower complex where apartments start at $2,215 a month.

The younger Ms. Pellicano, who lives in a one-bedroom with her boyfriend, was relieved. “It was nice to have family a little bit closer because you can have more control over your family’s activity and you could be more transparent about your activity,” said Stephanie Pellicano, who works in sales planning for Nike. “I ask my sister constantly, ‘OK, who did you see this week? Do I trust that person, do I not trust that person?”

While the pandemic drove many Americans back home to reluctantly live with parents or siblings because of financial or health concerns, siblings like the Pellicanos made the move by choice, seeking out separate apartments in the same building. In the era of the social bubble, these siblings took the directive a step further and created their own physical bubble, becoming each other’s neighbors, dog walkers and after-work buddies.

Now as the country reopens with access to the vaccine widespread and infection rates falling, these siblings are settling into a living arrangement that might not have happened if not for the events of the past year. In many cases, they are living closer to one another than they have at any point since childhood. The pandemic unexpectedly reshaped their relationships and their lives in long-lasting ways.

The pandemic was an “opportunity for adult siblings to connect with each other,” said Jonathan Caspi, an expert on sibling relationships and a professor of family science and human development at Montclair State University in New Jersey. “When the world feels very out of control and very alien, you crave something that is familiar. It’s almost like that Freudian idea of regression, going back to an earlier time when things were more familiar.”

These moves came at a moment of increased mobility in the country. Sixteen percent of American workers moved between April 2020 and April 2021, marking the first increase in migration in over a decade, according to an Apartment List survey. This time has also been an uncharacteristically easy one to move within the New York City area.

By last summer rents had plummeted and vacancies were at their highest levels in years, and are only now beginning to make a slow creep back. Eager for new tenants, some buildings see the relationships that tenants have with friends and family as a way to bring in new people. Many buildings have been offering residents cash or gift cards if they bring in a new tenant. Stephanie Pellicano, for example, received $500.

The Pellicano sisters now see each other four or five times a week, watching movies together, watering one another’s plants, and occasionally borrowing a household staple, like a roll of toilet paper. When their mother visits from Florida, she can float between the two apartments without traveling across town. The months spent in the same bubble, and later in the same building, changed their dynamic. “It’s nice, because I can say, ‘Hey I’m coming over,’” Jacqueline Pellicano said. “It’s just brought us all closer.’”

The Pandemic Push

For some, the pandemic provided an opportunity to make life changes that had been postponed for one reason or another for years. The support of a sibling made it easier to finally take that leap.

Sarah Conroy, 42, a fashion stylist, was living in Bushwick, Brooklyn, last spring. Her sister, Beth Conroy, 45, an acupuncturist and a digital marketing consultant, was living in a studio in Jersey City, where she had lived for 13 years. Suddenly, the sisters found themselves locked in apartments and neighborhoods they had outgrown.

In Jersey City, after more than a decade in the same apartment, many of Beth Conroy’s friends in the building had long since gone. The space was large, but dark.

“I was alone in my apartment. I don’t get any direct sun,” said Beth Conroy, who has a history of anxiety and depression, and began to relapse during the pandemic. “As I was taking care of myself, I realized that my environment was so important.”

Her sister Sarah, meanwhile, had been contemplating a move from Brooklyn to New Jersey for two years, but had never been quite ready. Last April, she had to put one of her dogs to sleep. Her sister “came right away and ended up staying a week,” Sarah Conroy said. “It was great to have the company, but also she was like, ‘You have so much sunlight in your apartment!”

Beth Conroy started spending half of each week with her sister in Brooklyn. “Sarah and I saw the benefit of being closer, of having access to each other, that we could be with each other and support each other that way,” Beth Conroy said. Back in New Jersey, she started hunting for a new apartment, touring the Urby, a complex in Harrison.

After seeing it, she decided it was worth paying an extra $1,000 a month in rent to live in a full service building. “I said, ‘I am going to do this. I don’t know how long this is going to go on. I need some sanity,’” she said. “I want the pool. I want the coffee shop. I want the courtyard.”

In August, Beth Conroy signed a lease for a one-bedroom, paying $2,137 a month, after factoring in three months free rent she received for signing a two-year lease. Sarah Conroy followed a few months later, moving into a one-bedroom at the end of October, weary from a Brooklyn summer filled with political protests and endless illegal fireworks.

By the end of the year, Sarah Conroy had lured her friend and longtime neighbor, Valeria Mezzano, to the Urby, too. Ms. Mezzano, 46, a research scientist at N.Y.U. Langone, had been Sarah Conroy’s neighbor since 2013, first in Williamsburg and later in Bushwick. Beth Conroy received a $1,000 credit for bringing in her sister, and Sarah Conroy received a $1,000 credit for bringing in Ms. Mezzano.

Sarah Conroy wonders if any of this would have happened if it hadn’t been for the pandemic. “This was a move that maybe I was afraid to make before just because it’s such a big change from the way I’d been living,” she said. “I’ve heard a couple of friends calling it the pandemic push.”

The three women asked the building management to program their key fobs so they could access one another’s apartments. Now the women walk their dogs together, and are growing vegetables in Urby’s community garden beds. Beth Conroy can see into her sister’s third-floor apartment from her apartment on the fifth floor, so she knows when she is home. “It’s kind of quirky and ridiculous, but I am also kind of creeped out by it,” Beth Conroy said. “I stand in the window like a creep and then I text her.”

“He Can’t Ignore Me Now.”

For siblings who were already attached at the hip, finding homes in the same building made an intertwined life that much easier. Last spring, Amanda Gerome, 33, was living alone on the Upper East Side. Her brother and business partner, Ryan Gerome, 30, was living with roommates in Murray Hill.

The siblings, co-owners of an electrical contracting company based in Queens, had always worked remotely. But the shutdown complicated their arrangements. Traveling between the two apartments became more difficult, and now Ryan Gerome had to coordinate his schedule with his roommates, who were also working from home. It didn’t take long for the arrangement to stop making sense.

“We speak to each other 12 to 20 times a day. We see each other a lot. Why are we living so far away from each other?” Ryan Gerome said of his thinking at the time. “We need somewhere where we could take the elevator right to each other. With the pandemic, it just all made sense.”

So they set out to find apartments in the same building. Amanda Gerome played the role of the family real estate agent. “I charged my brother his old Beats headphones to find our apartment. I said that’s his fee,” she said.

Once she found Waterline Square, a three tower complex with a mix of rentals and condos along Riverside Drive, the decision was a “no-brainer,” she said, largely because the building has Hudson River views and extensive amenities, including a great room with work stations where they could hold client meetings. Amanda Gerome, a former professional opera singer, was particularly drawn to the music and recording studio. (But she uses her Beats headphone hand-me-downs when she rides a Peloton in the building gym.)

She rented a sixth-floor one-bedroom and her brother rented a fourth-floor one-bedroom, both moving in on September 1. Rents for one-bedrooms at the Waterline start at $3,980.

Now, they travel between each other’s apartments constantly. “Ryan is on the phone a lot and sometimes he doesn’t pick up my calls,” said Amanda Gerome, who has since moved into a two-bedroom on the 16th floor. Rather than wait, she runs down to his apartment to get her answer. “He can’t ignore me now.”

For Single Parents, a Move for Support

Once Avidale Balanzat, 27, found out that both of her sisters had moved into Bay 151, a luxury complex in Bayonne, N.J., she wanted in.

“I said, “There is no way you guys are going to get to see each other and I am not going to be there,’” she said, referring to her sisters, Vydanez Balanzat, 25, and Rovi Balanzat, 30, who both moved into the building in July.

Avidale Balanzat, who goes by Avi, quickly arranged a building tour, asking the leasing agent to show her a unit facing the inner courtyard, not so she could see the swimming pool, but so she could have an apartment where she could see her sisters. “I wanted to see everyone from the balcony,” she said.

The entire living arrangement was happenstance. Rovi Balanzat, the eldest and a clinical application analyst at a hospital, found Bay 151 by mistake. In June, she was heading to Costco and made a wrong turn, ending up at the building, which was brand-new and looked to her like an oasis. A single parent with two young children, she was tired of living in a cramped Jersey City apartment with no amenities. At Bay 151, she was sold on the swimming pool, the children’s playroom and other amenities, quickly renting a two-bedroom. Two bedrooms in the complex now rent for $2,600 a month.

A few weeks later, her youngest sister, Vy Balanzat, an accountant, followed. The lease on her Jersey City apartment had expired and she saw the move as an opportunity to finally see her sister again. She had been living with a roommate who was a pharmacist, and so at a higher risk of contracting the virus. Because of the risk, Vy Balanzat hadn’t seen either of her sisters in four months — normally, she saw them every other week. Getting her own two-bedroom apartment at Bay 151 changed that.

Next came Avi Balanzat, the middle sister who works in information technology, and quickly found someone to take over the lease on her apartment in Jersey City. In September, she moved into a two-bedroom with her 11-year-old daughter.

For the Balanzat sisters, the move has been transformative. The cousins play together in the complex, and the sisters share in the child care, helping with homework and class time during a year of remote learning that has been taxing on the two single mothers. When the holidays rolled around, they didn’t have to make hard choices about how to celebrate. Their parents, who live in Jersey City with their 14-year-old brother, Arvinz Balanzat, were able to safely celebrate with them, too. Now that the family is vaccinated, their parents visit frequently and Arvinz sleeps over every weekend.

“The pressure was off, definitely, especially when we all moved in together,” Rovi Balanzat said. “We were able to limit the celebration to those who were already living in the same building.”

Together as the World Reopens

Now, as cities and states ease pandemic restrictions, these siblings find themselves with living arrangements they established to weather a difficult time. The moment may be passing, but they’re still living in the aftermath. Dr. Caspi, the sibling expert, sees that as a good thing.

“Close adult sibling relationships are linked to so many positive, good outcomes in other places in life,” he said, including better health, happiness and career and romantic success. “The fact that they’re having these opportunities to develop these relationships, even if they’re temporary in arrangement, has long lasting effects. They carry through your entire life.”

Some siblings interviewed for this article, like the Balanzat sisters and Amanda and Ryan Gerome, have no immediate plans to change course. For others, the time is fleeting.

Stephanie Pellicano isn’t certain how much longer she’ll be living in Jersey City, potentially leaving her sister, Jacqueline, behind in the apartment she moved into in November. “It’s kind of like it was meant to be that we get to spend the last of this time together,” Jacqueline Pellicano said. Once her sister leaves, “It’s going to be definitely strange because I feel like she was one of the main purposes of why I moved there.”

The Conroy sisters also see their time in Harrison as a transitional one. “It’s not inexpensive to live here,” Beth Conroy said. Her goal now is to save money for a down payment for a small apartment. “This really is a steppingstone.”

Her sister, Sarah Conroy, whose cost of living fell when she moved to Harrison, views the move as a “baby step to being out of the city.” She too, hopes to buy a home, but she’s not sure where. For now, she’s enjoying the time with her sister. “Where ever I end up,” Sarah Conroy said. “I’ll always make sure that I’m close to family.”

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