NYC Air Rights & Air Rights Transfers

by | Last updated Jul 2, 2023 | New York City, NYC Zoning, Property Development

The right to build or develop is based on calculations and formulas provided in local zoning codes. The available air rights on a property are the unused potential development rights for the given property. You can use your available development rights on your property or sell them to an adjacent property. In NYC, Air Rights rules and protocols come from the NYC Zoning Resolution.


What are Air Rights?

Air Rights are the right to develop a property in accordance with Zoning Regulations. The proper term for Air Rights is Development Rights. These development rights can be used to develop the given property or can be transferred to neighboring properties. 

The term air rights is not in the New York City Zoning Resolution. The Zoning Code uses the term “development rights,” which is what people normally mean when they say “air rights.”


Air Rights NYC Development Rights

If there is undeveloped floor area available, it can be added to the current property or sold to a neighboring one. In New York City, you can transfer Air Rights to other properties, commonly referred to as a “Development Rights Transfer” or “Air Rights Deal.” There are two ways to buy and sell air rights in New York City.

  1. Zoning Lot Merger
  2. Development Rights Transfer


How To Calculate Air Rights

If you have a property where you can build 100,000 square feet, your air rights are 100,000 sqft. If that property has a 60,000 sq ft building, your unused air rights (or unused development rights) are 40,000 square feet. You can either add 40,000 sq ft to your building or sell it to your neighbor, who can add it to their property development.


NYC Air Rights Calculations

Buildable Floor Area = Property Area x FAR

Available Air Rights = Buildable Floor Area – Used Floor Area

A particular set of zoning regulations governs every property in NYC based on its zoning district. The NYC Zoning Codes determine and restrict many variables on a building. The zoning code provides an FAR (pronounced F.A.R. but everyone rights it FAR). We have another post if you want to read about FAR or Floor Area Ratio. The FAR calculation determines how many square feet you can build on any property. The allowable square footage results in the Development Rights or Air Rights.


Air Rights Example 

In the following example, we will use an FAR of 10. in NYC, an FAR of 10 would be, for example, an R10 Zoning Lot. The FAR varies depending on what zoning district you are in. We will also use a property with a lot size of 100 x 100, which equals 10,000 square feet (the Property Area).

Allowable Floor Area = Property Area x FAR

Allowable Floor Area = 10,000 sq ft x 10

Allowable Floor Area = 100,000 sq ft. This number is the development rights of the property.

The owner of this property has the legal right to build a 100,000-square-foot building. Therefore the development rights are 100,000 square feet of air rights.

The FAR calculation determines the development rights. If the lot is empty, you have 100,000 sq ft of Air Rights to use on your property or sell to someone else.


Development Rights in NYC Zoning.

In NYC, people typically use the term Air Rights when describing Unused Development Rights. The Development Rights which can be bought and sold are the right to develop a property to the extent of that development in square feet. Therefore the unused development rights (AKA air rights) are whatever allowable square footage is not used. If not all the allowable square footage has been used one can allocate that square footage to an adjacent property by merging the zoning lots.


Air Rights In NYC = Unused Development Rights

The Department Of City Planning uses the term Unused Development Rights, more commonly referred to as Air Rights or Unused Air Rights. Personally I think unused development rights makes more sense and is easier for people to understand, but everyone calls it Air Rights in NYC. 

Air Rights or Development Rights NYC Zoning definition –

“Development rights generally refer to the maximum amount of floor area permissible on a zoning lot. When the actual built floor area is less than the maximum permitted floor area, the difference is referred to as “unused development rights.” Unused development rights are often described as air rights.”

Unused Development Rights = Total Development Rights – Actual Building Square Footage

Let’s assume we have a property with an allowable buildable floor area of 100,000 sqft but on a lot with an existing 60,000 sq ft building.

Unused Development Rights = 100,000 – 60,000

Available Development Rights = 40,000 square feet in this example. These are the Air Rights, which can be sold 40,000sf.


What Do You Do With Air Rights?

Building Addition Option 1: 

In the previous example, the property owner can add 40,000 square feet to the existing building if they want to.

New Building Option 2: 

The owner could demolish the building and build a new structure of 100,000 sq ft.

Sell Air Rights Option 3: 

The building owner can merge the zoning lot with another property, and the other property can add the leftover square footage to their development rights. You can sell these air rights to your neighbors, or if you own the neighboring property, you can develop it with the additional floor area. You also may have the option for a development rights transfer.


Zoning Lot Merger for Air Rights Sale

 In New York City, you can merge zoning lots so that a new development can use the undeveloped potential of an adjacent property. A zoning lot merger will be the easiest and most common way to buy and sell air rights.

A zoning lot merger is when you combine two or more zoning lots in order to do the zoning calculations of two or more properties as if they were one. The merger allows the property owner(s) to distribute the unused development rights however they wish between the two properties.

Zoning Lot Mergers do not require the tax lots to be combined. The individual tax lots can be owned by one owner or separate owners. Please do not confuse the term zoning lot with tax lots. They are two different things. A zoning lot is the basis of all zoning calculations. It can be made of one tax lot or many tax lots as long as they are all adjacent. If you do a zoning lot merger for air rights, you cannot separate the zoning lot later. 

We have another post that describes the difference between a Zoning Lot and a Tax Lot if you need more clarity.


How to calculate air rights transfer or zoning lot merger:

Let’s assume there are two properties next to each other, each with 100,000 sq ft of available development rights. That means the combined development rights would be 200,000 sf. 

A zoning lot merger allows you to allocate the square footage in any way you like as long as you comply with all other zoning requirements. You could have one building with 60,000 sq ft and then develop the other with 140,000 sq ft. To complete an air rights transfer, you must file documents with the Department of Buildings and the Department of Finance.


Transferable Development Rights (TDRs)

Transferable Development Rights are a way of transferring air rights without a zoning lot merger. TDRs are useful for transferring floor area between properties that are not touching. Applying TDRs is far less common and much more complicated than a zoning lot merger. 


NYC Air Rights and Zoning

As an architect, I study NYC zoning codes and protocols, which are complicated and quite involved. In this article, we reviewed some of the basic concepts regarding NYC Air Rights and Transferable Development Rights. This post does not assume to cover every possible issue or condition but provides a general overview of the topic.


Thank You for reading our blog post on NYC Air Rights.

I hope this was helpful. If you would like to speak to an architect about a specific project you are planning, you can contact us at Fontan Architecture directly.


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Jorge Fontan

Jorge Fontan

This post was written by Jorge Fontan AIA a Registered Architect and owner of New York City architecture firm Fontan Architecture. Jorge Fontan has earned 3 degrees in the study of architecture including two degrees from the City University of New York and a Masters Degree in Advanced Architectural Design from Columbia University. Jorge has a background in construction and has been practicing architecture for 20 years where he has designed renovations and new developments of various building types.