Extell Buys Air Rights for $34.9 Million

The air rights purchase from Hartz Mountain Industries adds development potential to Extell's 655 Madison Avenue supertall project on the Upper East Side.

Updated on Nov. 12, 2026 in Commercial

Extell Buys Air Rights for $34.9 Million

Extell Development paid $34.9 million to Hartz Mountain Industries for air rights tied to 36 and 34 East 61st Street, according to property filings recorded Tuesday. The purchase adds development potential to the company's planned 74-story mixed-use tower at 655 Madison Avenue.

Why it matters

The deal shows how developers in New York City assemble adjacent parcels and air rights to build taller, larger projects on constrained Manhattan sites. Extell has accumulated several nearby properties in recent years to clear a path for the Madison Avenue project.

The air rights purchase was valued at $34.9 million and recorded in property filings on Tuesday, November 11, 2026. The planned 74-story tower would include 154 condominium units and 233,000 square feet of office and retail space, though the final design has not been confirmed in the filings.

The players

Extell Development

Extell Development is a New York City real estate developer known for building large Manhattan residential and mixed-use towers.

Gary Barnett

Gary Barnett is the president of Extell Development who leads the company's major Manhattan projects.

Hartz Mountain Industries

Hartz Mountain Industries is a New Jersey-based real estate company that owns and manages commercial and residential properties in the New York area.

The details

Extell bought air rights attached to 36 and 34 East 61st Street in Lenox Hill from Hartz Mountain Industries. The purchase is tied to the company's planned tower at 655 Madison Avenue, where Chanel is a potential tenant.

2024: Extell bought the 655 Madison Avenue tower site for $160 million from Williams Equities.
March 2025: Extell bought 33-39 East 60th Street for $103 million.
February 2026: Extell paid $39.9 million to Metropolitan Club for 135,146 square feet of air rights from 1 East 60th Street.
November 10, 2026: A deed filing showed Extell's $27.9 million purchase of 1645 First Avenue.
November 11, 2026: The air rights purchase from Hartz Mountain was recorded in property filings.

Market Landscape

Air rights transfers under New York City's zoning rules have become a central tool for developers seeking taller towers on Manhattan sites where little land remains. Extell's accumulation of parcels and rights around Madison Avenue follows that pattern of consolidating development capacity block by block.

For New Yorkers, large towers like the planned 655 Madison project can add housing and retail space in Midtown and the Upper East Side over time. The transaction itself does not change prices or availability for current residents or shoppers.

The takeaway

Air rights purchases show how developers build larger projects in Manhattan by acquiring development potential from neighboring properties. Residents tracking the Madison Avenue project can follow future property filings for design and construction updates.