AIR RIGHTS IN GENERAL

Also known as “transferrable development rights,” air rights are the unbuilt, zoned square footage owners have above their properties. In some major U.S. cities, such as New York City, Boston, and San Francisco, these air rights can be sold and transferred under a cap-and-trade regime. They are a legal invention designed to balance density with preservation, allowing existing buildings—especially those historical—to transfer their air rights rather than be demolished.

• NEW YORK CITY EXAMPLE: If you are zoned to build 10,000 square feet on your lot but have only built 7,000, the difference is 3,000 square feet of air rights that you could transfer for use on another lot. The recipient could then build 3,000 square feet taller than previously allowed on their own lot, other zoning restrictions permitting.

Just where air rights can be used varies by city. We provide city-specific descriptions of prominent air rights regimes, but as a general rule, air rights transfers are often restricted to nearby lots, specially designated districts, or the same lot.