NYC Air Rights & Air Rights Transfers

by | Last updated May 31, 2020 | New York City, NYC Zoning, Property Development

Air Rights NYC rules and protocols come from the NYC Zoning Resolution. When people say Air Rights, they usually mean development rights. Development rights or air rights are the legal rights to build on a property in accordance with zoning laws. The right to build or develop are based on calculations and formulas provided in local zoning codes. The available air rights on a property is 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.


What are air rights?

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

Air Rights or Development Rights are the unused floor area that can be developed on a property. The unused floor area can be added to the property or sold to a neighboring property. In New York City Air Rights can be transferred to other properties commonly referred to as a “Development Rights Transfer” or “Air Rights Deal”. There are 2 ways to buy and sell air rights.

  1. Zoning Lot Merger
  2. Development Rights Transfer


How To Calculate Air Rights

Air rights are what you can build on a property as per zoning regulations. If you have a property where you can build a total of 100,000 square feet, your air rights are 100,000 sq ft. If that property currently has a 60,000 sq ft building, then 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 you can sell it to your neighbor and they can add it to their property development.

NYC Air Rights Calculations

The available Air Rights are the unused Development Rights on a Property.

Buildable Floor Area = Property Area x FAR

Available Air Rights = Buildable Floor Area – Used Floor Area

A property owner can develop or sell available Air Rights

Every property in NYC is governed by a very specific set of zoning regulations. The NYC Zoning Codes determine and restrict many variables on a building. The zoning code provides an FAR or Floor Area Ratio. This determines how many square feet you can build on any given property. The allowable square footage determines the Development Rights or Air Rights.

Development Rights are determined by calculating the allowable floor area.

In the following example we will use an FAR of 10 this 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 that has a lot size of 100 x 100 which equals 10,000 square feet (that is the Property Area).

Allowable Floor Area = Property Area x FAR

Buildable 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. Therefor the development rights are 100,000 square feet of air rights.

The FAR calculation determines the development rights. In this case if the lot is empty you have 100,000 sq ft of Air Rights.

Air Rights NYC & Development Rights in NYC Zoning.

In NYC Air Rights typically means Unused Development Rights. A Development Right is the right to develop a property and 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 – 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

As per the example above assuming an allowable buildable floor area of 100,000 but on a lot with a 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.

What Do You Do With Air Rights?

Building Addition Option 1: 

In the example given, the owner of the property can add 40,000 square feet to the existing building if they want to. (Read another post discussing Vertical Building Additions.)

New Building Option 2: 

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

Sell Air Rights Option 3: 

The owner of the building can merge the zoning lot with another property and the other property can add the leftover square footage to their development rights. These rights can be sold 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

NYC Air Rights zoning lot mergers

In New York city you can merge zoning lots so that a new development can use the undeveloped potential of an adjacent property. The unused potential is what people usually refer to as Air Rights. A zoning lot merger will be the easiest and most common way to buy and sell air rights.

Air Rights NYC – Zoning Lot Merger

A zoning lot merger is when you combine 2 or more zoning lots in order to do the zoning calculations of two or more properties as if they were one. This allows the property owner to distribute the unused development rights to any one of the 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. The individual tax lots can be merged as well or kept separate. 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.

How to calculate air rights transfer or zoning lot merger:

If there are 2 properties next to each other and each is allowed 100,000 sq ft. That means the combined is 200,000. 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 feet. Documents must be filed with Department Of Buildings and Department Of Finance in order to complete an air rights transfer.


Development Rights Transfer

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. That is why they are typically used in cases of landmark properties or in certain special zoning districts.


NYC Air Rights and Zoning

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


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

I hope this was helpful if you are interested in learning more about NYC Air Rights please feel free to contact us directly.


Contact Fontan Architecture


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.