“The key here is that we have gone from a reactive position to a proactive position,” said Timothy Hogan, the Buildings Department’s deputy commissioner of enforcement. “There are bad-actor landlords who have gone out of their way to create scenarios that force us to vacate tenants, and now we can stop them before it gets to that point.”

Despite those efforts, “on the ground, I don’t see any changes or improvement,” said Shekar Krishnan, a director at Brooklyn Legal Services Corporation A, a nonprofit legal organization that represents Ms. Alvillar. He added: “It is certainly strange to be on the other side of an eviction, but it also feels so good to know Tranquilina can finally go home.”

For her part, Ms. Alvillar finds it all a bit overwhelming. Since leaving her apartment, she has been living with a nephew in Coney Island, Brooklyn. It is too far to travel to Bedford Avenue to sell her wares, so she has eked out a living cleaning houses.

While she was away, her building was transformed. Where once there were cramped kitchens and windowless bathrooms, there are now hardwood floors, exposed brick and stainless steel appliances. Tile and decorative wood line the building’s entryway; industrial light fixtures and artwork hang on the walls.

“This has been very difficult, very devastating, and I’m scared that the landlord will try and intimidate me again,” Ms. Alvillar said through an interpreter. “The building is now for people who have a lot of money, who can pay big, expensive rents. I hope it will be O.K.”

Tenants at 193 Bedford seemed unaware of what had taken place around them.

“Wow, I had no idea,” said Selma Radzivanovich, 20, a student at the New School who lives above Ms. Alvillar’s apartment in a two-bedroom place that she shares with a roommate, each of them paying $1,700 a month. “That is awful that the girl downstairs is just going to get evicted even though she did nothing wrong,” Ms. Radzivanovich added, while acknowledging the unfairness involved “for the other tenant who was forced out.”