What Are Air Rights in Commercial Real Estate?

When you buy a piece of land or a building, you are not just purchasing what is at street level. You are buying a vertical column of space that extends both below ground and upward, as far as local zoning allows. That upward portion is what the industry calls air rights, and in dense urban markets, those rights can be worth as much as the building sitting beneath them.

Air rights have existed as a legal concept for centuries, but they have rarely been more relevant than they are right now. New York City’s sweeping City of Yes zoning reform, passed at the end of 2024, has fundamentally changed who can sell development rights, where those rights can travel, and who benefits. Air rights transfers in the city are on pace to hit their highest volume since 2016. Developers who once could only acquire rights from directly adjacent parcels can now reach further, and landmark buildings that were largely locked out of the market are now active participants.

Whether you are a developer, a building owner sitting on unused square footage, or a tenant trying to understand what a neighboring site can build, this guide covers how air rights work, what they are worth, and what is changing.

Key Takeaways

• What Air Rights Are: The legal entitlement to develop the vertical space above a property, up to the limit set by local zoning.
• They Are Tradable Assets: Air rights can be bought, sold, leased, or transferred under specific zoning rules.
• Current Pricing: In prime Manhattan locations, development rights currently trade for $300 to $600+ per buildable square foot.
• City of Yes Impact: NYC’s City of Yes legislation, passed in late 2024, significantly expanded who can sell air rights and where they can be transferred.
• Hidden Value: Building owners who have not used their full zoning allowance may be sitting on a significant, often overlooked, asset.

The Legal Origins of Air Rights

The concept is rooted in a Latin legal principle: Cuius est solum, eius est usque ad coelum et ad inferos, which translates roughly as “whoever owns the soil, it is theirs up to Heaven and down to Hell.” The phrase first appeared in medieval Roman law in the 13th century, was incorporated into English common law in the mid-18th century, and made its way into American property law from there.

The doctrine held up reasonably well until aviation arrived. In the early 20th century, courts began amending the definition of vertical ownership to mean only the space “within range of actual occupation,” creating the legal room needed for air traffic to operate above private land. Today, the Federal Aviation Administration governs navigable airspace above a certain altitude, generally starting at 500 feet in rural areas and 1,000 feet in urban areas. Below those thresholds, property owners retain development rights subject to local zoning.

The practical consequence is that your ownership of a building does not extend infinitely upward. It extends as far as your zoning district allows you to build. What you cannot use, you may be able to sell.

Floor Area Ratio: How Air Rights Are Measured

Air rights in practice come down to a number called Floor Area Ratio, or FAR. FAR is the ratio of a building’s total floor area to the area of the lot it sits on. Local zoning sets the maximum FAR for each district, which effectively caps how much square footage can be built on any given site.

Here is a simple example. If you own a 10,000-square-foot lot in a district with a FAR of 5.0, zoning allows you to build up to 50,000 square feet of floor area. If the building currently on that lot only occupies 20,000 square feet, you have 30,000 square feet of unused development rights. Those rights can potentially be sold or transferred to a developer who wants to build larger on an adjacent or nearby site.

The higher the FAR a district allows, the more valuable the unused rights tend to be, because there is more demand from developers trying to maximize what they can build in high-density zones.

How Air Rights Are Transferred

There are three primary mechanisms for transferring development rights from one property to another. The rules vary by city and zoning district, but the basic framework is consistent across most dense urban markets.

Zoning Lot Mergers

The most common transfer mechanism. If your lot shares at least 10 feet of its boundary with a neighboring lot, the two can be merged into a single zoning lot for development purposes. The unused development rights from one parcel can then be applied to the other, allowing a developer to build taller or larger than the site would otherwise allow. In New York, zoning lot mergers have been the engine behind many of the city’s supertall residential towers, including the assemblage that made Extell’s Central Park Tower possible.

Special Purpose District Transfers

Certain zoning districts allow development rights to move between non-contiguous sites, typically to serve a specific planning goal such as preserving a neighborhood’s character or concentrating density near transit infrastructure. NYC’s East Midtown special district is a well-known example. SL Green’s One Vanderbilt tower, completed in 2020, used this mechanism to acquire approximately 400,000 square feet of development rights from several landmark properties in the district.

Landmark Transfers

Under landmark preservation laws, designated historic buildings can transfer their unused development rights to receiving sites that may be across the street or, in some cases, several blocks away. This mechanism allows landmarks to generate revenue from their air rights without altering or demolishing the protected structure. Buyers get the development rights they need; the landmark gets the income to fund maintenance and preservation.

NYC’s City of Yes legislation, passed in December 2024, significantly expanded this mechanism. Landmark owners can now sell unused development rights to a broader geography of receiving sites, and the certification process has been streamlined. Developers can also acquire rights from side-street properties and transfer them to avenue-fronting sites, a combination that was not widely available before. The result has been a sharp acceleration in air rights activity throughout 2025.

What Air Rights Are Worth

Pricing varies enormously depending on location, zoning, and the specific terms of each deal. In New York City, which has the most active air rights market in the country, development rights in prime Manhattan locations currently trade for $300 to $600 or more per buildable square foot. Outer borough markets are considerably less: recent zoning lot mergers in Downtown Brooklyn and Williamsburg have seen rights trade in the $150 to $250 per buildable square foot range.

The two largest recent deals illustrate just how much money can be involved at the top of the market. In August 2024, Howard Hughes Corporation paid $40 million for air rights above Piers 16 and 17 at South Street Seaport to enable a planned 27-story residential tower at 250 Water Street. Separately, a partnership of Ken Griffin, Vornado Realty Trust, and Rudin Management agreed to acquire up to 525,000 square feet of development rights from St. Patrick’s Cathedral at $312.50 per square foot, a deal valued at between $98 million and $164 million depending on how much of the purchased rights the developers ultimately use. The proceeds will support the Cathedral’s maintenance and preservation.

Outside of New York, air rights markets are thinner and pricing is less standardized. Chicago, Boston, and a handful of other dense urban markets have active transfer mechanisms, but most smaller cities lack the zoning infrastructure to support liquid air rights trading. The concept still applies wherever FAR-based zoning exists, but the ability to monetize unused rights is largely a function of local demand for density.

Who Should Pay Attention to Air Rights

Developers and Investors

Air rights are most obviously relevant to developers who need more buildable square footage than a given site’s zoning would otherwise allow. Acquiring air rights from adjacent or nearby properties is often cheaper than buying additional land outright, and in constrained urban markets it may be the only path to a project of meaningful scale. For a broader look at how property acquisitions fit into the buy-vs.-lease decision, see our guide to buying vs. leasing office space.

Building Owners

Owners of low-rise buildings in high-density zones, historic properties, and certain institutional owners like churches, co-ops, and municipal entities are among the most common sellers of air rights. If a building is not using its full FAR allowance, the unused portion is a real asset, even if it does not appear on any balance sheet. Many building owners in New York have historically been unaware of this value or unable to access it due to regulatory barriers. The City of Yes changes have made it considerably easier for a broader set of properties to participate.

Air rights sales also carry tax implications. Gains from the sale of development rights are generally subject to capital gains tax, and the structuring of the transaction can significantly affect the tax outcome. For a broader overview of how commercial property is taxed, see our guide to commercial property taxes.

Tenants in Adjacent Buildings

If you occupy space in a building next to a low-rise or a parking lot, it is worth understanding what could be built there. Air rights transactions can enable construction that blocks views, increases foot traffic, or changes the character of a neighborhood. Leases rarely provide tenants with recourse against these changes, but understanding the development potential of adjacent sites is useful when negotiating lease terms and renewal options. For more on evaluating a building before you commit, see our guide to understanding Class A, Class B and Class C office buildings.

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Frequently Asked Questions (FAQ)

Q: Can air rights be sold separately from the building?
A: Yes. Air rights can be separated from the underlying property and sold, leased, or transferred independently. The transaction requires its own legal documentation and must comply with local zoning rules governing how and where rights can be transferred.

Q: Do air rights transfer automatically when a building is sold?
A: Yes, unless they have already been sold separately. When you purchase a property, the air rights come with it unless a prior owner has transferred or sold them to another party. A title search should reveal whether any prior air rights transactions have occurred.

Q: Are air rights the same as development rights?
A: The terms are often used interchangeably, but development rights is more precise in a zoning context. Air rights technically refers to ownership of the vertical space above a property, while development rights refers specifically to the right to build within that space up to the FAR limit. In practice, most transactions involve the latter.

Q: How do I find out how many air rights my building has?
A: Start with your local zoning code to determine the FAR allowance for your district, then compare it to your building’s existing floor area. A real estate attorney or land use consultant can provide a formal development rights analysis. In New York City, the Department of City Planning’s ZoLa (Zoning and Land Use Application) tool is a useful starting point.

Q: What is the City of Yes and how does it affect air rights?
A: The City of Yes is a major zoning reform passed by New York City in December 2024. Among many changes, it expanded the geography over which air rights can be transferred, streamlined certification for landmark transfers, and enabled new combinations of sending and receiving sites. The reform has led to a significant increase in air rights activity, particularly for landmark buildings and properties in the Midtown South area.

Q: What are air rights worth?
A: It depends entirely on location and zoning. In prime Manhattan, development rights currently trade for $300 to $600+ per buildable square foot. In outer borough markets like Downtown Brooklyn, the range is $150 to $250. Outside New York, pricing varies widely and markets are generally thinner. A formal appraisal is recommended for any transaction of meaningful size.

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Air rights are an invisible but real dimension of property value, and in markets where land is genuinely constrained, they can be among the most significant factors in a development’s feasibility. For building owners who have never assessed their unused FAR, the calculation is worth doing. For developers assembling sites in dense markets, understanding the full landscape of transferable rights in a given area has become a competitive necessity. And for everyone in between, the simple fact is this: in commercial real estate, value does not stop at the roofline.