Air rights, zoning laws, and the skyscraper

Despite Manhattan’s incredible population density, much less of the borough’s skyline is dominated by high-rise buildings than one might expect. Instead, short, stubby, often pre-war buildings sit side-by-side to massive, sleek skyscrapers in a mottled, uneven patchwork throughout the island. Considering space goes for such a premium in the borough, one might ask why—wouldn’t it make sense to build as upward as possible?

Manhattan’s mottled skyline isn’t by choice. Much of New York City’s development is dictated by zoning laws that, depending on the area, limit the height of all buildings or prohibit the rebuilding of preexisting structures. In particular, many older buildings are designated protected by the Landmarks Preservation Commission, leaving them essentially untouchable. Even as neighboring buildings dwarf them, such buildings are unable to expand upwards or make any appreciable changes to their structure at all.

However, rather than let the empty air space of these landmarked lots go to waste, these buildings are selling what’s known as their “air rights” to other buildings nearby. Neighboring buildings that would otherwise be limited by zoning regulations to a height of, say, ten floors, can purchase the air rights of a three-story landmarked building to build an additional seven floors and bypass the zone’s height restrictions. Such an arrangement allows the city to justify protecting landmark buildings without hampering the city’s overall growth and development potential.

Frustrating as it may be for landmarked building owners who are unable to expand upward and make use of their potential allotted square footage, selling air rights is no small financial consolation. As the city has increasingly grown upwards, the air rights market has heated up, and fast. According to the New York Times, a square foot of air space would have gone for $45, but now, it’s $450 a square foot. Many of New York’s recent big projects, such as the Hudson Rail Yard and One57, have made use of the air rights provision and have bought up hundreds of thousands of dollars’ worth, allowing them to far exceed the normal building height limits. Indeed, one skyscraper planned in the Hudson Rail Yard project is a staggering 80 stories. The trend, as far as most architects see it, will only continue as Manhattan becomes increasingly wealthier and more constrained for space.