One of the World’s Cleanest New Skyscrapers Collides With the Future

“This building is clearly a showpiece,” said Richard Leigh, a professor of physics at Pratt Institute in Brooklyn. “The question is what it’s putting out in the way of emissions.”

Landlords such as SL Green say New York City’s new laws will force dramatic changes. Unlike energy codes of the past, one of the key laws, which restricts pollution, doesn’t merely apply to new construction: Existing buildings, no matter how small or how old, must gradually comply and retrofit as well, potentially at eye-watering cost.

Like SL Green, all New York landlords will be forced to look into an uncertain future and face stark choices.

For now, the future of New York’s office towers can be seen at 270 Park, a half-finished behemoth rising a few blocks north of One Vanderbilt. It will have no gas line at all. When it opens, it will be the city’s greenest skyscraper ever, owing to the city legislation banning use of fossil fuels in new construction — rules that didn’t exist when One Vanderbilt was being conceived.

The law, passed in 2021, is new enough that the city, in fact, is still working out the details of how it will be enforced. “In recent weeks, we have reached several important milestones on the implementation of this law,” said Laura Popa, deputy commissioner for sustainability at the Department of Buildings. Ms. Popa expected more rules to be added “later this year.”

Mr. Wilcox of SL Green supports the city’s efforts to make buildings cleaner, saying that an all electric future “makes sense.” Meantime, One Vanderbilt has welcomed its new tenants. Deep underground, an expanded transit hub rivaling an airport concourse recently opened next door. And dozens of floors above, the building’s powerful turbines twirl in the sky.

Will those turbines eventually end up being replaced with something else? “To be determined,” Mr. Wilcox said.