Last year, Richard Mack, an executive at the multibillion-dollar investment group Apollo Real Estate, which happens to be owned by his father, paid $23 million for Spence-Chapin's 24,463-square-foot headquarters at 4-8 East 94th Street. (It was built from three 19th-century row houses, which explains that address.) Mr. Mack got permission from the Landmarks Preservation Commission in December to ...

Twelve months and 26 days ago, according to city records, the nonprofit adoption agency Spence-Chapin sold its 24,463-square-foot headquarters at 4-8 East 94th Street, built from three 19th-century row houses, to Richard Mack, a managing partner of his father’s multibillion real estate investment group, Apollo Real Estate Advisors. He paid $23 million. But real estate executives are wilier ...