NYC Air Rights

NYC Air Rights & Air Rights Transfers

(Last Updated On: November 6, 2018)

When people say Air Rights they usually mean development rights. Development Rights or Air rights are the legal right 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. These can be used on the property or sold to adjacent properties.


New York Air Rights

What are air rights?

The term air rights cannot be found 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 with restrictions of course. 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 development.

NYC Air Rights Calculations

Every property in NYC is governed by a very specific set of zoning regulations. The NYC Zoning codes will 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 is the Development Rights or Air rights.

Development Rights are determined by calculating the allowable floor area.

In this 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

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. 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 means Unused Development Rights. A Development Right is the right to develop a property and the extent of that development in square feet. 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.”

As per 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 = Total Development Rights – Actual Building Square Footage

Unused Development Rights = 100,000 – 60,000

Unused 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. We have another post that discusses 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. This is for transferring floor area between properties that are not touching. This is far less common and much more complicated than a zoning lot merger. this is typically done for landmark properties or in certain special zoning districts.


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 Fontan ArchitectureIf you would like to get professional help with Zoning to determine your development rights please check out an article we wrote about Zoning Analysis. Also you can learn more about our NYC


New York Architects, Jorge Fontan

Author Jorge Fontan AIA

This post was written by Jorge Fontan, a Registered Architect and owner of Fontan Architecture.


  • Ramiro Lundberg

    December 31, 2016 4:33 pm

    Do you mind if I quote a few of your posts as long as I provide credit and sources back to your webpage?
    Please let me know if this is ok with you. Regards!

  • Jesse Moss

    November 21, 2017 2:47 pm

    If a building is in C6-3A and its Commercial FAR is 10 & Residential FAR is 7.52 and lot area is 2,235sf what is the potential buildable SF?

    Is it 22,350 sf of commercial space PLUS 16,807 of residential for a total of 39,157 of buildable SF?

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