Will the Bloomberg Balloon Violate the D.C. Height Act?
The answer's no, according to Liz Diller, principal of Diller Scofidio + Renfro, the architecture firm that designed the Bloomberg Balloon, even though it'll be taller than 130 feet tall once it's inflated. In a TED Talk posted in April, Diller talks about how her firm came to the award-winning design. She gets into a comparison between the Hirshhorn Museum and Sculpture Garden's Gordon Bunshaft–designed bunker and its neighbors on the National Mall. (Funny stuff, too: Diller digs up a review of the original Hirshhorn building by Ada Louise Huxtable, then the architecture critic for The New York Times: "This is born-dead, neo-penitentiary modern.")
Some of those buildings, she observes, exceed the statutory height limit. That's because the features that put them over the line are exempt. The Height Act allows that "[s]pires, towers, domes, minarets, pinnacles," and some other functional features such as chimneys "may be erected to a greater height than any limit" in the act.
Should the Bloomberg Balloon be known as the Diller Dome?
Given that she compares it to the Pantheon (!), at least in this visual, maybe Diller wouldn't mind if it bore her name.
In any case, the Height Act is mute on inflatable structures, but the Bloomberg Balloon required the same approval from the U.S. Commission of Fine Arts and the National Capital Planning Commission that a traditional dome would—so someone evidently buys that argument. (Fine Arts chair Earl A. Powell told the Hirshhorn to "go forth and inflate," Smithsonian reported.) The Height Act says the mayor of D.C. has some say, too.
Go ahead and watch the whole thing to see a guy inflate an actual model of the whatever-it-is.