Buckling columns at the former Pfizer headquarters this week forced evacuations across seven Midtown East blocks.

The incident raises new questions about office-to-residential conversion, one of several tools the city has used to add housing. It is also a tool Mayor Zohran Mamdani leaned into because it fit his affordability narrative.

Mamdani has framed housing as his central promise. He has paired headline-grabbing ideas like reviving the Sunnyside Yard megaproject with more incremental tools already on the books.

Office conversions fall into the second category. The mechanism predates his tenure and builds on former Mayor Eric Adams’ City of Yes for Housing Opportunity rezoning, approved in December 2024. City officials said at the time that it could add 80,000 homes over 15 years.

That ordinance made office-to-residential conversions easier. New York City has led the nation in these conversions for several years. Mamdani inherited a pipeline with about 12,000 units and continued championing it because it aligned with his affordability pitch.

“Hopefully this doesn’t have a pause effect, or people revisiting the City of Yes legislation, but I think that might be kind of a natural impact of this,” Michael Webb, a real estate attorney with New York City firm Farrell Fritz, told HousingWire TBD.

Lawsuit followed, but lost

The City of Yes legislation was passed by a narrow margin. Some City Council members opposed the law and called it a favor to developers.

A coalition of civic associations and elected officials from Staten Island, Queens, Brooklyn, and the Bronx sued the city over the City of Yes early last year. The suit did not challenge the policy’s housing goals. Instead, petitioners claimed the city violated state and local environmental review law in adopting it.

They argued the city unlawfully segmented City of Yes into three phases – carbon neutrality, economic opportunity and housing opportunity – to avoid assessing cumulative impacts. Petitioners also said the city failed to take a required “hard look” at harms such as sewer overflows, school overcrowding, and shadows, and never proposed any mitigation or alternatives. They lost the case in November.

Building bigger

The 235 East 42nd St. project was the marquee conversion example. Developer Metro Loft is converting two 1970s-era office towers built as Pfizer’s headquarters. One rises 10 stories, and the other stands 33 to 37 stories.

Metro Loft is adding 19 stories to the shorter building, bringing the total to 1,600 units. It is the largest office conversion in city history. The project demonstrated how vacant towers could be converted into badly needed apartments at scale by leveraging the state’s 2024 tax abatement for buildings with 25% affordable units.

That symbolism now carries added weight. A 2023 Moody’s Analytics study found only 3% of city office buildings were structurally suitable for conversion. That caveat drew little attention during the boom, but it now prompts sharper questions about whether incentives pushed marginal buildings – including one requiring a 19-story vertical addition atop a 1970s tower – into conversion too quickly.

The city comptroller’s office has flagged how these projects work financially, stacking tax exemptions against tight construction timelines. Critics argue that the dynamic can favor speed over caution. The concern echoes broader skepticism about big, complicated housing fixes, and this incident suggests even smaller-scale conversions carry underappreciated structural risk.

“With these office-to-residential conversions, it’s sort of like you’re building the plane while you’re flying it,” Webb said. “This really highlights the complexities when you’re doing a very ambitious office-to-residential conversion project.”

He noted that office buildings are typically built for heavier loads than residential. Aging structures can make that capacity uncertain in advance.

“If there’s a way that we can use this to make the process better, safer, let’s examine it,” Webb said. “I don’t want to see this becoming a problem that begs 1,000 solutions that aren’t needed.”