Mr. Curtin’s landlady, who lived in the ground-floor unit of the two-family house, made no secret of her disapproval.

“She said: ‘You shouldn’t be partying with girls this late. Girls like that are no good,’ ” recalled Mr. Curtin, 33, who works in television production. “She was very interested in my love life.”

The landlady’s assessments of those friends, while not necessarily or consistently off the mark, were disconcerting, said Mr. Curtin, who had previously — and happily — lived in a landlord-occupied building. There, the owners had given him espresso, not advice.

“It was awkward that she was making comments at all,” he said. “But I wanted the relationship to be good while I was living there. She meant well, but really, it was none of her business.

“But,” he added, “maybe it was her business, because I was living in her building.”

For the majority of those who rent apartments in New York City, the landlord is simply the person to whom they make out a monthly check, a faceless being who races to the bank with that check — but doesn’t always respond with similar speed when there’s a problem with the boiler.

For some, however, the landlord is not abstract. For better (he’s always around checking up on things) or worse (he’s always around checking up on things), the landlord is the upstairs or downstairs neighbor. It’s the durable stuff of movies and sitcoms, like the 1960s series “Hey, Landlord” and the ’70s series “Three’s Company.”

Life with the landlord has its own particular complications and compensations. These range from the too-much-in-your-face and too-much-in-your-business sort, to the homeowner whose table always has an extra place. If the relationship is contentious— well, you know where the door is. But if it’s harmonious, that could translate into attractive terms when the lease comes up for renewal.

There are no hard figures on how many New York City apartment buildings have an in-house landlord. But it’s more likely to be the arrangement in small buildings, more likely on side streets than avenues, and more likely in the outer boroughs than Manhattan. That’s “because the housing stock, a lot of duplexes, is built for it,” said Jonathan J. Miller, the president of the real estate appraisal firm Miller Samuel.

“Having the landlord in the building is more common than you think,” he added. “But it isn’t something you see in the marketing or listing of a building, and it’s not seen as an amenity like a gym or a roof deck that will affect the rent you pay.”

There can be advantages to having a live-in landlord. “The assumption is that things will get fixed quicker because the landlord is there,” Mr. Miller said. “He’s subject to the same inconveniences as the tenants, so if the hot water is off, he has an incentive to fix it.

“By the same token, you may have to be more mindful of your behavior than in a large building where the landlord lives elsewhere.”

Sunny Zachi, the owner of Alpha Properties, a rental agency in Manhattan, says he makes a point of outlining the virtues and drawbacks of living in a landlord-occupied building. “I tell a prospective tenant that the building is clean and well taken care of. But then I say, ‘Guys, the landlord lives there, so there are things you have to be cautious about; he doesn’t want people who have parties until 4 a.m.’ ”

Landlords and tenants have to find a balance between privacy and intimacy that suits everyone.

The women who cycle in and out of the three-bedroom second-floor apartment that Melanie Adsit rents out in Astoria are tenants, but often they also become friends.

“We actually hang out and have dinner parties,” said Ms. Adsit, 37, an art education consultant who lives on the first floor with her husband, Alex Eaton, 36, a freelance cinematographer for film and television, and their newborn daughter. And sometimes, tenants become family. Ms. Adsit’s brother married a woman who had lived upstairs.

“I feel our tenants have been very patient with us,” Ms. Adsit said. “They know they have a good deal, so they’re not demanding.”

Megan McDonell, one of Ms. Adsit’s tenants, says that good deal includes the backyard. “Melanie and Alex are like, ‘Go on out there and invite your friends over,’ ” said Ms. McDonell, 31, an editor at a publishing company. “During Hurricane Sandy both my roommates were stranded elsewhere, so Mel and Alex invited me down to dinner and to hang out with them.”