New York City’s Department of Buildings (DOB) has halted construction work at the third office-to-conversion project in Manhattan this month.

The DOB issued a partial stop-work order at SL Green Realty’s $805 million conversion project at 750 Third Avenue in Midtown East, which is set to result in 680 residential units and potentially see 11 floors added.

The halt comes after the near-collapse of the former Pfizer headquarters earlier in July, when steel beams at MetroLoft and David Werner’s 235 East 42nd Street project buckled and sparked the evacuation of 10 surrounding Midtown blocks. Earlier this week, GFP Real Estate’s conversion project at 222 Broadway in the Financial District was also halted after cracks were found on a newly added floor.

In the case of 750 Third Avenue, it seems as if steel columns were not welded properly and inconsistencies were reported, according to the DOB. As a result, inspectors have temporarily stopped all steel work above the eighth floor at the 34-story property, according to The New York Times, which first reported the news.

“During our structural reinforcement prep work, prior to beginning any overbuild work, we identified an on-site condition that differed from the plans that were submitted to the city, which was visible only after completing initial preparation work,” an SL Green spokesperson said in a statement to Commercial Observer.

“There are no structural issues with the building, and we are already working with the licensed professional engineer of record to address this condition,” the spokesperson added. “We do not anticipate any impact to the overall project schedule, with other work ongoing, and have already submitted our request to rescind the partial stop work order.”

While the Pfizer buckling certainly spurred a renewed scrutiny of ongoing conversion projects in New York City and an increased focus on safety, these types of partial stop-work orders are not uncommon. The DOB issued 7,000 such stops in 2025, the Times reported.

Isabelle Durso can be reached at idurso@commercialobserver.com.