Not that smokers will get kicked to the curb right away. New tenants must sign a contract promising not to smoke anywhere in the building, including their private terraces or balconies. If they break the rules, they can be evicted. But those already renting will not face the same fate until after they renew their leases and sign the no-smoking contract. With a turnover rate of 10,000 a year, Related’s apartments could conceivably be smoke-free in a few years’ time.

Critics point out that tenants could always lie about their habit, and hide it successfully. Also, it can be very difficult to evict tenants — especially those whose rents are regulated, as they have strong protections and guaranteed lease renewals.

But some smokers — and even nonsmokers — worry about privacy infringement and say Related is overreaching. “It’s just mean,” said Polina Skoch, a resident of Related’s One Union Square South, who smokes half a pack of Marlboros a day.

Even though she signed her lease earlier and is out of the immediate line of fire, Ms. Skoch said she worried about the “Big Brother” vibe that the changes could facilitate, because Related will mostly rely on neighbors to report on neighbors. “I thought it couldn’t get any worse when the city banned smoking in parks,” she added.

But Jeffrey I. Brodsky, the president of Related Management, says people can’t expect such freedoms in an apartment building, where resources are shared. “It’s not unlike somebody playing their tuba at two in the morning and compromising their neighbors’ efforts to enjoy their apartments,” he said. “There’s an expectation of certain behavior.” As for the increasingly trendy smokeless cigarettes, Related says that because they don’t emit plumes, they aren’t banned — although “we reserve our right to adjust our program if they become known as hazardous to others,” a spokeswoman wrote in an e-mail. Related’s condominiums won’t be affected.