That, he figured, was the end of things. But about a year later, he got a call from his former landlord, Kay Doobay, 72, a retired home health care worker who lives on the first floor of the two-story house. The roommate hadn’t paid rent in a year, she told Mr. Armlovich, and she was taking him to housing court. Would Mr. Armlovich be willing to testify that the upstairs apartment had been in good condition, with smoke detectors, when he lived there? Mr. Armlovich, who had found Ms. Doobay kind and generous (she often cooked dinner for them and once gave a subletter sleeping on the floor a futon), told her he would.
After Mr. Armlovich testified, the roommate was ordered to pay six months of back rent — half the amount he owed, according to Ms. Doobay. A few months later, Ms. Doobay approached Mr. Armlovich with his own deal: a reduced rent of $350 a month in exchange for finding and vetting other tenants for the top-floor apartment.
Mr. Armlovich agreed, on the condition that they charge reasonable rates for the other rooms. He didn’t want to have his reduced rent come at the expense of others, he said. And since he would be selecting his roommates, he felt lower rents would ensure a good pool of people from which to choose.
He moved back into the apartment two and a half years ago, quickly finding roommates through friends and Bushwick Boarding Bazaar, a Facebook group. The largest room rents for $850 a month, while the two smaller ones are priced at $700 a month, all utilities included. Ms. Doobay also provides all the furnishings, including a sectional couch and a TV in the living room. And, not infrequently, a home-cooked Indo-Guyanese dinner.
“Kay is very doting,” Mr. Armlovich said. “She even switches out the curtains seasonally. She has winter curtains, Easter curtains, summer curtains.”
Emily Hamilton, 21, who moved into one of the $700-a-month rooms this May, said she was pleasantly surprised to find a setup that felt so “homelike.”
“When I lived in Queens before, the apartment never felt very secure,” she said. “Here, we all know Kay. She’ll come up and be like, ‘I just made dinner for you.’ One day, I just mentioned, ‘Oh, a plant would be nice here.’ And the next day, there’s a plant.”
After a long stretch of departing roommates slotting in their friends, this year Mr. Armlovich has had to earn his keep: Two of the roommates moved into a higher-end apartment complex in the neighborhood, and another left to live with her boyfriend.
Mimi Schweid, 24, a friend of Ms. Hamilton’s from Marymount Manhattan College, moved into the other $700 room this spring. The $850 room, meanwhile is still vacant: Mr. Armlovich said he had talked to a number of people but hadn’t yet found a good fit.
“If Alex says he recommends someone, we trust him,” said Ms. Doobay, adding that she was O.K. with leaving the room empty for a few months waiting for a compatible renter.
At the moment, however, Mr. Armlovich has a much more difficult task: He’s looking for someone to take over his room — and his role — in the house. This fall, he’s moving to Massachusetts to start a master’s program at Harvard Kennedy School.
But, he said, he is optimistic that he will be able to find a trustworthy replacement: After his first unfortunate turn in the apartment, he has had only good roommates.
“The important test for me is, ‘Have you ever had a good roommate?’” said Mr. Armlovich. He came to this wisdom after realizing his last bad roommate was always talking about how everyone had screwed him over. “If the answer is ‘no,’ then they’re the bad roommate.”
An earlier version of this article misstated the ages of Emily Hamilton and Mimi Schweid. Ms. Hamilton is 21, not 24. Ms. Schweid is 24, not 21.