Loophole closing

An amendment filed by the planning department at de Blasio’s request would limit mechanical spaces to a height of 25 feet, and require multiple mechanical floors to be at least 75 feet apart. Otherwise, they would count toward the building’s floor area as set by zoning rules, which determine how tall a building can be.

Kallos worries that without intervention, the mechanical voids will just keep growing—to 300 or 400 or 500 vertical feet of dead space. The practice is especially noticeable on Billionaire’s Row—a strip of super-luxury condo buildings just south of Central Park. Mechanical voids make up about a quarter of 432 Park Ave., Manhattan’s tallest completed condominium tower, according to Kallos. The building’s minimalist boxy design can be seen from every borough.