New renderings of One World Trade Center released last week give a more detailed look at a slimmed-down design for the Lower Manhattan Skyscraper’s 408-foot spire. Not only could the design change keep the tower from reaching a symbolic height, it might also compromise its bid to be the tallest building in the United States.

Skidmore Owings & Merrill (SOM) and structural consultant Schlaich Bergermann und Partner’s original design for the spire enclosed it in a tapering shield of white fiberglass plates. But last year, in a move that saves $20 million in construction costs, the development team of the Durst Organization and the Port Authority of New York & New Jersey decided to take off the cladding, resulting in the narrow metallic mast visible in the recent renderings. If that spire is just a bolted-on antenna, rather than an architectural element, it would not count toward the building’s official height, according to the Council on Tall Buildings and Urban Habitat, the organization recognized as the official score-keeper for towers across the globe.

One World Trade would then clock in at just 1,368 feet, earning it second-tallest status behind Chicago’s 1,451-foot Willis Tower (formerly the Sears Tower). In fact, antennas on Willis Tower are not counted toward the building’s height for the very same reason, says Kevin Brass, the council’s spokesman. In addition, One World Trade would fall well short of its symbolic goal of 1,776 feet tall—the date the country’s Declaration of Independence was signed—which was chosen to honor the victims of the terrorist attack that brought down the original World Trade Center.

David Childs of SOM says the decision is disappointing. “Eliminating this integral part of the building’s design and leaving an exposed antenna and equipment is unfortunate,” he said in a statement in the New York Times, when the change was unveiled.

Yet for their part, the developers dispute the characterization of the spire as an antenna, saying that it will be illuminated at night, and that it will not be used as a transmitter, though as in the original design, broadcast equipment will hang from it. Plus, the design change will make caring for the spire less treacherous; workers won’t have to scale it to replace fiberglass panels, says Jordan Barowitz, a Durst spokesman: “That’s the stuff of ‘Mission Impossible,’ not skyscraper maintenance.”

Brass says the council plans to meet with Durst and review the new plans and will reserve final judgment until the project is complete. He also acknowledges that some amount of tweaking was expected before the 104-story tower was finished in 2014. “We are a still a long way from a completed project,” he said. “Designs change during projects all the time.”