Buckling Scare Puts MetroLoft’s Playbook Under Microscope

The dramatic structural failure at MetroLoft’s conversion of Pfizer’s former Midtown headquarters is drawing attention to one of the developer’s signature redevelopment techniques.

The temporary evacuation around 235 East 42nd Street earlier this month, after columns buckled and floors sagged during construction, has brought renewed focus to MetroLoft founder Nathan Berman’s “scoop-and-stack” approach, according to Crain’s. While investigators continue probing what caused the incident, engineers and developers say the method itself underscores the growing complexity of converting postwar office towers into apartments.

The strategy essentially hollows out portions of a building’s lower floors, creating interior lightwells while transferring that unused development potential to new floors added at the top.

The reshuffling solves one of the biggest obstacles in postwar office conversions, dealing with oversized floor plates with deep interior space that lack the windows required for residential units.

The technique is a hallmark of Berman’s projects. At the Pfizer redevelopment, MetroLoft planned to carve out a courtyard-like opening through the building while using both the recovered floor area and available air rights to expand the project from roughly 973,000 square feet to 1.3 million square feet. The added density includes a 15-story cantilevered expansion above 235 East 42nd Street, where the structural failure occurred.

The approach is hardly unique to the Pfizer site. MetroLoft employed a similar strategy at 25 Water Street, where carving multiple lightwells into the former office tower helped create enough developable floor area for a 10-story rooftop expansion. The building, now known as SoMA, opened last year as the city’s largest office-to-residential conversion with 1,320 rental apartments.

Berman described the buckling as the result of insufficiently reinforced columns rather than a flaw in the overall concept, telling the New York Times it was a “typical construction mishap.” According to engineers, the planned reinforcing steel plates — intended to strengthen the columns against the weight of the new residential floors — seemed to be missing from the 19th through 21st floors.

The building has since been stabilized, though damaged floors will need to be rebuilt as city and law enforcement officials continue their investigation.

— Holden Walter-Warner