As part of the renovation, the architects added a 10-story “overbuild”. Photo © Ivane Katamashvili, click to enlarge.

The original building had slit-like openings. Photo © Ezra Stoller / Esto

Before it was SoMA, the building was known as 4 New York Plaza, and later as 25 Water Street. Completed in 1969, the 22-story reddish-brown brick monolith was designed by Carson, Lundin & Shaw as an operations center for Manufacturers Hanover Trust. It had only slit-like windows on much of its facade, in a pattern that, according to urban lore, was intended as a reference to computer punch cards and the equipment housed within. Over the years, the tower would serve as office space for a variety of tenants, including JPMorgan Chase, which had acquired Manufacturers Hanover after a series of mergers, as well as the New York Daily News. Fast-forward to 2022, when GFP Real Estate, Metro Loft, and Rockwood Capital purchased the building. In the wake of the Covid pandemic and the consequent drop in demand for office space, their goal was to transform it into apartments, hiring CetraRuddy, a firm that has designed several office-to-residential conversions.

The adaptation project came with a set of formidable challenges, but the biggest one was the immensity of its floor plates. Each was more than 40,000 square feet. Depending on the size of its lot, a typical new apartment tower might have floor plates of only 13,000 square feet, says architect John Cetra, CetraRuddy cofounder with Nancy Ruddy. This scale meant that much of the building’s interior would be far from windows, and the daylight and fresh air they would provide. The expansive floor area would make it difficult to design units that were desirable, or even legal, since the building code requires that all habitable rooms in residences have operable windows. For converted office buildings, however, it allows mechanical ventilation for spaces that are considered incidental or secondary to the residential use.

CetraRuddy’s solution entailed cutting two light wells, totaling about 3,000 square feet in plan, from the steel-framed tower’s interior, and then, as zoning regulations permit, adding back this floor area with a 10-story glass-and-metal-clad “overbuild” on top. The strategy also included inserting a new elevator core in the center of the building, while removing some elevators from the existing core along the south wall. Overall, the tower now has 13 elevators—nine fewer than there were originally, since it has a lower population in its residential incarnation, says Cetra.

The scheme, with its vertical addition, triggered the need for upgrades to the lateral system. The new floors add to the facade’s surface area, and therefore increase the wind loads, explains Joe Basel, a partner with Gilsanz Murray Steficek, the project’s structural consultant. To mitigate these forces, the engineers distributed new diagonal bracing throughout the structure, spreading out the loads, and thereby allowing the team to avoid retrofitting the foundations. Not having to install subgrade reinforcement was key to the project’s financial viability, says Ruddy.

Another cost-saving strategy was opting to retain the existing envelope, even though a typical office-to-residential conversion would involve replacing the facade. There the architects added new insulation and cut openings in the brick, allowing for large high-performance windows. To be more in keeping with the glass-and-steel towers that surround the building, they painted the elevations a light gray. The approach was not only less expensive than recladding, but it was also faster and more sustainable, says Ruddy, referring to the considerable carbon embodied within the masonry.

The apartments in the revamped tower have new, larger windows. Photo © Ivane Katamashvili

Inside, the apartments have an almost Scandinavian feel, with blond-wood-look vinyl floors, quartz countertops, and glossy white laminate cabinets. They are fitted out with electric appliances, including in-unit washers and driers. Some have views of New York Harbor and the Brooklyn waterfront. A few even have balconies created in a space where a small outer court had separated a stairway from the rest of the floor area. Other apartments are oriented toward the new interior light wells, which means their only view is of the unit across the way. On the whole, however, they have been ingeniously configured to make the most of every square foot. For instance, floor area far from the perimeter has been incorporated into apartments as “home offices”—rooms that cannot be marketed as bedrooms or living rooms because they are windowless and mechanically ventilated but are nevertheless useful. In all, there are more than 70 apartment layouts, reflecting the complexities of the conversion.

A few apartments have balconies. Photo © Ivane Katamashvili

The SoMA website emphasizes the building’s amenities—100,000 square feet of them—including indoor and outdoor pools, a spa, pickleball and basketball courts, a bowling alley, a coworking space, a sun deck, and grilling facilities. The rents for the apartments, which are being leased in stages, reflect the extensive offerings. Among those currently listed as available is a fourth-floor studio offered at $3,702 per month, and a tenth-floor three-bedroom, three-bath unit at $9,450. The 330 affordable apartments, found throughout the building—and with finishes, appliances, and layouts identical to those in the market-rate ones—will be awarded through a city-administered lottery, with much reduced rents ranging from $932 to $3,286, depending on unit type as well as household size and income.

The tower has two pools—one in the basement (this image) and an outdoor one on the roof, where the building steps back to the addition. Photo © Ivane Katamashvili

With the first residents just starting to move in, and the lottery closing early this month, it is still too soon to know how successful the building’s financial formula will be. However, the project has many lessons for developers and architects, from its apartments with their well-planned layouts and smart finishes, to its efficient structural retrofit strategies and thoughtful approach to reuse. Hopefully, SoMA will be one of many conversions to come, bringing those office towers, underutilized since Covid, back to life.

Click plan to enlarge

Click plan to enlarge

Click section to enlarge