The Hotel Bossert has stood over Montague Street since 1909, and it's about to become Brooklyn's first branded residential condo — the Ritz-Carlton Residences, per renderings released this week.

Chestnut Holdings and Naftali Group are behind the conversion, according to New York YIMBY, which published the first renderings September 19. A hotel-to-condo conversion at this scale in Brooklyn Heights is not a small job: it means gutting and rebuilding a landmarked, roughly 100-room building floor by floor while keeping its 1909 shell intact — new mechanical risers, new elevators, new unit separations, all inside a building the Landmarks Preservation Commission will have final say over.

That LPC review is the actual gate here. Nothing structural or exterior moves without a Certificate of Appropriateness, and any contractor bidding this job needs to know the facade, the lobby, and the roofline are frozen by landmark designation — the money is entirely in what happens behind those walls.

For GCs and subs, a project like this means early relationships matter: developers moving through LPC typically line up their construction manager and key trade contractors well before permits clear, because approval timelines run long and a CM who can plan around landmark constraints is worth more than one who can't.

No construction timeline, GC, or permit filing has been made public yet. The first move for anyone chasing this work is watching DOB NOW for a landmark alteration filing under the Bossert's block and lot, and watching the LPC calendar for the Certificate of Appropriateness hearing — that's the date this job becomes real.