A look at Isaac Rosenberg’s real estate portfolio

The Brooklyn community leader and investor died this week

462-484 Kent Avenue in Williamsburg and Isaac Rosenberg
462-484 Kent Avenue in Williamsburg and Isaac Rosenberg

Rabbi Isaac Rosenberg – the Satmar community leader, Certified Lumber proprietor and Brooklyn real estate investor – had parted with much of his portfolio by the time of his death Tuesday.

Rosenberg and his brother Abraham, who operated under the entities Waterfront Realty, Cl Spe LLC and Bp Spe LLC, among others, own at least five properties, all located in Williamsburg and Borough Park, according to Reonomy and an analysis of public records performed by The Real Deal.

The best known was the development site at 462-484 Kent Avenue on the Williamsburg waterfront, which they’ve owned since the 1980s. The brothers secured a zoning variance on the 94,500-square-foot lot site, currently home to Certified Lumber’s headquarters, back in 2010, allowing for 500,000 square feet of residential development rights.

The Rosenbergs planned to build a gargantuan 754-unit rental complex at the site, to be known as the “Rose Plaza on the River.” About a third of the planned units were to be designated affordable.

But in 2013, the pair changed course, offering the property for sale, asking $210 million. Actual offers came in far below that however, topping out at around $150 million.

Last year, the site drew the attention of HFZ Capital’s Ziel Feldman and former Vornado Realty Trust boss Michael Fascitelli, now of Imperial Companies, who reportedly visited in person.

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The brothers’ other properties are far more modest.

They own a 35-unit, 21,000-square-foot residential property at 188 Clymer Street in South Williamsburg, a 15,000-square-foot warehouse and retail location at 4601-4613 Utrecht Avenue in Borough Park, a 88,300-square-foot factory building at 1 Division Street in South Williamsburg, and a 4,000-square-foot development site with about 10,000 square feet of air rights at 1144 46th Street in Borough Park.

They’ve also sold off a number of properties over the years, including a 13,250-square-foot factory building at 376 Flushing Avenue in South Williamsburg, which they sold to a group of investors led by Zelig Weiss in 2014 for an unknown price.

Isaac, who often signed his name “Isack” on real estate documents, was a pillar of Brooklyn’s Satmar Hasidic community, serving as President of Congregation Yetev Lev D’Satmar. Rosenberg was instrumental in effort to construct the group’s synagogue on Hooper Street in 2006. A team of 200 workers, many of them volunteers, completed construction of the project in just 14 business days, working 18 hours a day and violating a handful of Department of Buildings rules in the process.

Isaac Rosenberg died this week when he and a few friends were caught in a rip tide while swimming in the Atlantic Ocean off Miami Beach.

Abraham Rosenberg is now the sole principal of the brothers’ various companies. He was not immediately available to comment for this story.

Isaac’s funeral was held Wednesday morning at the Hooper Street synagogue he helped construct.