“Axel’s track record is the opposite of prolific,” Cohen said. “There are some people that when they perceive the time right, they buy and develop property like mushrooms, but Axel seems to be selective.”

Stawski’s tenants include Fitch Group Inc., which has one of its two international headquarters at the billionaire’s Broad Financial Center at 33 Whitehall St., and the central bank of Norway, at 505 Fifth Ave.

“They’re very hands on -- in a positive way," Sunderland said of Stawski and his team. “I’ve done this for 30 years and I’ve never heard anything bad said about him. That’s phenomenal in New York.”

Stawski also co-developed three residential buildings in Manhattan’s Soho and West Village neighborhoods. At the newly constructed 27 Wooster St., a $28.5 million penthouse went under contract after just six days on the market in December 2014, according to listings website StreetEasy. The billionaire stuck to his boutique approach on the eight-unit building as well, such as through requesting that every window open inward so they’d be easier to clean.

“This was rather special from my point of view,” Douglas Hocking, an architect with Kohn Pedersen Fox Associates, the building’s lead designer, is quoted saying in marketing material published on the development’s website. “I have never seen a building where every single piece of glass was actually a window that you could open.”

Holocaust Survivor

Stawski was born in Frankfurt in November 1950 to Moniek and Sara Stawski, both Jews who survived the Nazi regime. His father -- who spent more than two years at a Polish slave-labor camp and weighed 36 kilograms (79 pounds) at the war’s end -- began building apartments in Frankfurt in 1960 after running a small business selling chocolate, coffee and alcoholic drinks following the war, according to his autobiography, “My Life.”

Axel Stawski, the second of five children, studied in the U.K. as an undergraduate at University of Birmingham and later attended New York University where he obtained a master’s degree in law and an international law doctorate, according to the school’s website.

He had moved to the U.S. by 1971 and received general power of attorney from his father two years later at age 22, which gave him enlarged responsibilities for real estate transactions, according to a Sept. 11, 1984 filing with New York City Department of Finance. Axel became directly involved in real estate in the late 1970s, when a Long Island shopping center in which his father had invested came across financial trouble, according to a 1991 story in The New York Times.

Around that time, the family bought 950 Third Ave., a 32-story office tower in midtown Manhattan, with German billionaire Karl-Heinz Kipp. The 343,000-square-foot building is owned today by Naomi Altholz, the youngest Stawski sibling, and her husband, Andre, according to a Sept. 22, 2010  report from Real Estate Weekly.