When it’s dinnertime and Michele W. Miller’s husband, Jerome, has gone AWOL, Ms. Miller reflexively checks in with her co-op’s superintendent, Carlos Muñoz.

Nine times out of 10, Mr. Miller is down in Mr. Muñoz’s apartment, where the two are watching sports, discussing their children or commiserating about their endless struggles to quit smoking. “Jerome will tell me, ‘I’ll be right back,’ and then doesn’t come for a few hours,” said Ms. Miller, a lawyer and novelist. “A few nights ago I texted Carlos and he wrote back that if I didn’t let Jerome eat there, he wouldn’t come up to do a repair.”

The couple’s friendship with Mr. Muñoz began five years ago when they renovated the kitchen in their Hudson Heights apartment, and he moonlighted as the contractor. The bond solidified when, during a school vacation, Ms. Miller, the mother of twin boys, now 11, invited Mr. Muñoz’s twin daughters, now 13, to come up and hang out. One day when the baby sitter was unavailable and Ms. Miller wasn’t able to miss work, Mr. Muñoz stepped unto the breach and refused payment.

Mr. Miller, meanwhile, has taken Mr. Muñoz’s daughters to the park and to the beach with his sons, and on several occasions has helped his buddy the super snake a drain and haul garbage. “Some of our fellow shareholders,” he said, “look at me like I’m crazy.”

Well, maybe just a little crazy. It’s true that some New Yorkers confine their interactions with the doormen and the super to pleasantries — anodyne observations about the weather, perhaps disparaging comments about an underperforming sports team — and requests: Would you please give this package to the U.P.S. guy? Could you get me a cab? “They’re the employers” goes their thinking; the doormen and the super are the employees, service staff whose job it is to serve. Being friendly is one thing; being friends is another.  (Undoubtedly, plenty of doormen are similarly inclined to be courteous but distant.)

But to others, like the Millers, the super is more than the guy who fixes the intractable leak under the kitchen sink, the doorman more than someone who ferries the groceries, delivers the mail and keeps watch on the security monitors. These men (and they are almost always men) are pals. They’re family, extended family perhaps, but family just the same.

Chances are you see them a lot more than you see people who really are family members. Chances are they know more about you and play a bigger role in your life than certain family members do, so what’s wrong with bringing them a latte and bagel from the corner Starbucks? And if you have an extra ticket, why not ask them to come along to the Yankees game?

“It’s understandable that building workers often become friendly with tenants, who they may see every day for years and sometimes decades,” said Kyle Bragg, the secretary-treasurer of Local 32BJ of the Service Employees International Union, which represents doormen. “It’s not unusual to find tenants who say their staff feels like ‘family.’ But similar to any other workplace, personal relationships shouldn’t interfere with workers’ ability to perform their jobs.”

Kathy Braddock would argue that the existence of these personal relationships can actually enhance the ability of porters, doormen and supers to do their jobs — and can immeasurably benefit a building’s residents. “We are a city of service people,” said Ms. Braddock, a managing director of the real estate firm William Raveis New York City. “Every time you walk out your door, whether you go to the dry cleaner or the liquor store, you can create a relationship with those people that will make New York work for you. And part of making it work is having the staff of your building be your family,” continued Ms. Braddock, who has lived in the same Park Avenue building for 30 years, and has a quasi-kinfolk relationship with the recently retired superintendent, Fernando Duque.

When, for example, Ms. Braddock was working full time and one of her sons was sick, Mr. Duque made it his business to make periodic visits upstairs to check on the patient and make chicken soup. When one of those sons was a teenager and the super observed him going up to the roof — a forbidden area — with some friends, “he made the assumption that the boys were doing something they shouldn’t be doing, scolded my son and came to tell me about the incident,” said Ms. Braddock, who was grateful for the intervention.

“I’ve been out to dinner with the super’s family and traded recipes with his wife,” she added. “I offered his children some guidance when they were getting ready to apply to college, and I gave his daughter-in-law advice about her decorating business.” More recently, just before the super ended his tenure, “he came up to my apartment, we had a bottle of wine and talked about life and change and our kids,” Ms. Braddock said.

Before Arlene Kagle met the man who would become her second husband, several of the staff members of her co-op on West End Avenue were included in her will. The dollar figure wasn’t huge, but there they were, all listed as beneficiaries — the super, the handyman and the night elevator man, Mario Reyes.

“I was divorced, and next to my brother and my parents they were the closest thing to family I had,” said Dr. Kagle, a psychologist in New York and Richmond, Va. “They looked after me. They worried about me, and I wanted them to know that if anything happened to me that what they had done hadn’t gone unnoticed or unappreciated.”

“I remember having a terrible blind date,” she recalled, “and he was angling for a second date as we stood in the lobby and I tried to edge away.” Fortunately, Mr. Reyes was on duty and read her body language with a clarity that was lost on her suitor. “As soon as I took a step into the elevator,” she said, “Mario slammed the gate in the guy’s face and whisked me up to my apartment.”

For her part, Dr. Kagle helped a doorman’s son snag a summer job, counseled him about appropriate workplace behavior and took the superintendent and his family out to dinner.

Some shareholders have taken it a step further, inviting doormen for a weekend in the Hamptons or offering them the use of a vacation property, and some service staff members have availed themselves of the opportunity.

That would not be considered appropriate for employees in one of the 600 buildings managed by FirstService Residential. “The roles of doormen, porters and superintendents must remain purely professional,” said Dan Wurtzel, the firm’s president. “They cannot form friendships with individual residents, because that will foster an environment of favoritism, a perception that not all residents are treated equally,” he said. “Word gets around that you took the super out for a drink or for dinner and people start to think, ‘Oh, now he’s going to do this and that for the resident.’ ”

According to Mr. Wurtzel, whose company has an employee handbook spelling out the proper terms of engagement with residents, it’s perfectly fine for a doorman or a porter who pulls Thanksgiving duty to accept a plate of turkey and stuffing from a resident, and fine to say yes when a shareholder who’s moving out of the building offers a castoff couch or flat-screen television. But it’s probably not O.K. to say yes to drinks, dinner or the Hamptons. (Employees are required to run such invites past their supervisors.)

“Can you imagine how it would be perceived if the individual offering the invitation were on the board of the building and at some point there were problems with this employee?” Mr. Wurtzel said. “It gets hard to make objective decisions when you’re dealing with a friend.”

Lois Tamir and Laura Finfer, the principals at Leadership Excellence Consulting, view condos and co-ops as variants of an organization. “Key to a well-functioning organization,” they wrote in an email, “is clarity about roles.” With ambiguity come risks. When a professional relationship crosses into friendship, they continued, “It can put the professionalism of the staff into question and create discomfort for observers because the roles of the players are now unclear.”

Suddenly home sweet home starts to seem just as political as the office. Steven R. Wagner, a real estate lawyer at Porzio, Bromberg & Newman, is the counsel for a co-op whose superintendent has a close relationship with an elderly shareholder. His appointed rounds — for no additional remuneration — include going to the resident’s apartment and checking on him to make sure everything is O.K.

“The super is not the best super,” Mr. Wagner said. “He’s a little lackadaisical about his chores, but because he has this friendship with this elderly man who’s a former board member and very influential, residents are reluctant to take steps to do anything.”

Mr. Wagner also tells of a building staff member who, when he was dismissed by the board of an East Side co-op, lobbied the shareholders he had befriended to stage a coup. It was unsuccessful.

For some building residents, being chummy with the service staff is just part of their personality. “I tend to be friendly with everyone,” said Dan Nainan, an Intel engineer turned comedian and motivational speaker who lives in a co-op in Chelsea. “I’m friendly with my neighbors and walk their dogs, and I’m friendly with the doormen and fix their computers and don’t charge them,” said Mr. Nainan, who routinely invites the doormen and the super to his parties and has taken the super, Jose Noel Medina, to a concert.

For others it’s family tradition. “I grew up in the city and the super and the doormen were my mother’s best friends,” said Brett Beldock, an interior designer. “She was a single parent and if she was running late at work, they came up to look in on my brother and me.”

Before her recent move to a condo in Harlem, Ms. Beldock lived on the Upper East Side in a rental building whose doormen became an extension of her interior design business. “They would approve wallpaper samples for me,” she said. They would also comment on blind dates, calling Ms. Beldock on the intercom and giving her a whispered preview. Whenever she gave a party or went to a holiday family dinner, she took food to the staff. “I’m back to my familial ways in my new building,” Ms. Beldock said. “The doormen know how my company works. They’ll examine what’s being delivered and make sure everything is right.”

She acknowledged that some residents are much more formal than she. “But if you have a more personal relationship with the staff I think you get so much more.”

Sarah Knapp, for example, is getting help with her Spanish. “I have multiple doormen and I have a friendship with one of them,” said Ms. Knapp, founder of Outdoor Fest, an event that connects New Yorkers with al fresco adventures. “I told him I was trying to learn Spanish, and whenever there’s time, he works on it with me.”

He’ll correct her when she muddles the past tense, and additionally, several times a week, the two will talk — in English — about their families and work. When she left her job and began her own company, Ms. Knapp, who lives in a co-op in Brooklyn, talked to the doorman about her life shift, “and he was very supportive. He’s just really nice and awesome and friendly.”

“With him,” she said, “it’s more like ‘Welcome home,’ rather than ‘Let me open the door for you and then I’m going to close it.’ ”

Jerome Miller, a marketing manager turned high school chemistry teacher, said that when something in the apartment is broken, it might get fixed more quickly thanks to his relationship with the superintendent, Mr. Muñoz. “If he’s visiting, I’ll say: ‘Will you take a look at this?’ ” he said. But, Mr. Miller hastily added, “that isn’t the basis of the relationship. Carlos is my friend. We have similar values. I understand a lot of his challenges and he understands my challenges. There’s nothing we don’t talk about.”

These ties “make my job easier,” Mr. Muñoz said. “I think if I have an emergency and can’t do something or can’t be around, people will be more understanding.”

But even the most egalitarian residents are hesitant to push things beyond a certain point. When the Millers’ previous super invited the family to the Poconos, “we never went, so maybe that was where the boundary was,” Ms. Miller said. And when Ms. Knapp is having a dinner party during her favorite doorman’s shift, “I think: ‘Should I invite him up when he’s on his break?’ ” she said. “But I think there’s a line. There is a line. This is his job and this is my home.”