In the 1980s, the company emerged as one of New York City's most prominent developers of luxury hotels, upscale condominium apartments, office towers, and mixed-use projects.

For one hotel, Mayfair House, he persuaded Sirio Maccioni to open Le Cirque, which quickly became one of New York's top restaurants, cementing the restaurateur's reputation.

Initial dissent from the community subsided when the condos went on sale, as most went to middle-class buyers including neighborhood residents, and not, as had been feared, to wealthy people intent on pushing out the locals.

[4] Zeckendorf followed the success of The Columbia with the Park Belvedere, hiring the same architect, Frank Williams, to design the first luxury residential high-rise on Columbus Avenue.

One of the early "sliver" buildings, rising 35 stories on a narrow, 12,000 square foot site at the corner of West 79th Street, the Park Belvedere made creative use of air rights to increase the allowable height—a strategy that became a Zeckendorf trademark.

Hailed as a pioneer in opening up the Broadway corridor to residential development, Zeckendorf went on to build three more West Side condominiums, the Copley, Central Park Place, and the Alexandria.

Zeckendorf was credited with helping revitalize the Union Square area, launching an upsurge of development along Park Avenue South and in the nearby Flatiron District.

After leasing space in the 49-story office tower to blue-chip firms Cravath, Swain & Moore and Ogilvy & Mather, the complex was cited as another pioneering move by Zeckendorf, legitimizing Eighth Avenue as a corporate address.

[2][8] In a rare venture outside of New York, Zeckendorf served as the managing development partner for the Ronald Reagan Building and International Trade Center, a 3.7 million square foot complex on the Federal Triangle in Washington, D.C., completed in 1998.

[9] Zeckendorf's policy of bringing in multiple partners to reduce his risk failed to protect him from major losses after the real estate market downturn in the late 1980s.

According to The Wall Street Journal, a habit of personally guaranteeing loans along with giving outside investors a greater share of profits than is customary contributed to Zeckendorf's financial problems.

Also like his father a knowledgeable wine collector, Zeckendorf was active for many years in La Confrerie des Chevaliers du Tastevin, a society of Burgundy connoisseurs.