As the growing revolt against “supertalls” shows signs of making a dent in zoning policies, not everyone is in agreement on how the regulations should be interpreted and applied.

Two weeks ago, the Department of Buildings threated to revoke the permit for a 775-foot condominium tower on the Upper West Side unless its developer, Extell, revised the design of a 160-foot tall mechanical void. Originally intended to house a building’s mechanical equipment, these spaces have in recent years been stretched by luxury developers into excessively tall empty spaces, with the goal of maximizing building heights so that more apartments can be offered on higher floors without violating zoning limits.

Then, last Friday, the other shoe dropped when City Planning announced a proposed zoning amendment to regulate mechanical voids. Going forward, voids taller than 25 feet would count toward the residential project’s permitted floor area, creating a deterrent for developers looking to supersize their voids.

But as one Upper East Side group is quickly learning, voids are not the only device developers can use to create height. Moreover, not everything that looks like a void is a void.

For more than a year, Friends of the Upper East Side Historic Districts has been fighting a condo project on East 62nd Street over a design that incorporates a similar height-adding trick. Developed by Real Estate Inverlad and Third Palm Capital and designed by 432 Park architect Rafael Viñoly, the plan calls for a 510-foot, 32-story tower with a gap between the 13th and 16th floors that would effectively raise the upper half of the building.

The building has been referred to being on "stilts." A writer for YIMBY described it as “a Jetsons-esque podium to boost its upper levels high into the neighborhood skyline.”

Last year, architectural critic Paul Goldberger tweeted his assessment of the project:

Despite a challenge from Friends, the Department of Buildings ruled last year that the height-boosting design feature of the building was permitted under existing zoning.

And apparently that still holds true. Although the recent turn of events gave Upper East Side residents hope that the DOB would pull the plug on the East 62nd Street design, the DOB on Friday said that nothing had changed regarding that project.

Unlike Extell’s development, the plan for 249 East 62nd Street calls for “outdoor space” along with “structural outriggers,” according to the DOB. In a statement to Gothamist last week, the agency said that the design had precedent in other buildings, citing the Citicorp Building at 601 Lexington Avenue as an example. The base of that building has been described as being on stilts.

“Under the Zoning Resolution, outdoor space is not governed by the same rules as fully enclosed mechanical space, such as what is proposed for 36 West 66th Street,” the DOB statement read.

Andrew Rudansky, a DOB spokesperson, later clarified the agency’s position, saying that contrary to reports in the press, plans for 249 East 62nd Street are not considered to have a mechanical void—the only kind of structure that would be limited by the City Planning regulations as currently proposed.

The developers could not be reached for comment.

City Councilmember Ben Kallos, who represents the Upper East Side, responded by saying that he was "horrified" that DOB's interpretation appeared to be at odds with that of City Planning. In the past he has asked City Planning to consider adding more height restrictions in certain residential neighborhoods.

Citing 180 East 88th Street and 200 Amsterdam, two other projects that opponents say have used loopholes to add building height, Kallos said, "It's DOB that has been willfully refusing to follow zoning regulations."

Similarly, Rachel Levy, the executive director of Friends, expressed disbelief and frustration at the DOB’s position.

The Upper East Side project, she said, had been “one of the main poster children for this issue.” The 249 East 62nd Street plans were reported to be the impetus behind City Planning’s latest efforts to rework the zoning law.

“You don’t have to be a zoning expert and look at that column and to know that it’s wrong,” Levy said. “It’s shocking to me.”

City Planning did not immediately respond to a request for comment.

Levy also accused the DOB of not publicly communicating the status of the project. In April 2018, the agency took up several zoning challenges Friends made to the plans, including one involving whether the building violates its permitted lot coverage. On Tuesday, the DOB said those issues were addressed by the developers months ago.

Levy said her group was never informed.

She also argued that City Planning’s proposed zoning amendment should be interpreted as a “catchall” for all height-boosting design features, not just mechanical voids.

“The fact that two bodies of government have different ideas of proposed legislation is pretty concerning,” she said.

Ultimately, it will be elected officials that have the last word. The proposed zoning text amendment is set to undergo a public review process that will require approval by the City Planning Commission as well as the City Council.

Kallos signaled that when the proposal reaches the City Council, he would be prepared to revise the wording so as to regulate unenclosed voids such as the one at 249 East 62nd Street.

This means that whether the project gets built as currently designed may depend on how quickly the developers, who already have a foundation permit but have yet to receive a building construction permit, can construct it.

"I've raced to the finish line with a developer before and won," Kallos said.