So hot is Brooklyn’s real estate market that Manhattan Borough President Scott Stringer came all the way from across the East River to headline the program at the Brooklyn Historical Society’s quarterly real estate luncheon today. “I came to Brooklyn on behalf of the outer boroughs,” he quipped in his introductory remarks.

However, the draw for many real estate professionals wasn’t Stringer, but David Bistricer. The developer recently purchased the former Bossert Hotel and has been busy transforming it back to a hotel. It had served as a community facility for the Jehovah’s Witnesses since the 1980s.

Bistricer said he’s brought on Jeff Klein and Atif Youssef, both affiliated with the Chetrit-backed King & Grove Hotel brand, to oversee the conversion of the former Jehovah’s Witnesses property, at 98 Montague Street, into a 300-room boutique hotel; he said it that the 103-year-old property would not be flagged by any major hotel chain and would continue to be named after its original developer, lumber magnate Louis Bossert. Bistricer estimated that the hotel would open in about a year, with little alteration to the interior spaces, which were meticulously maintained by the Witnesses. Instead, he said, the work would be limited to upgrading the electrical and plumbing systems. The plans are awaiting approval from the city’s Board for Standards and Appeals, he said.

Bistricer noted the average room size would be between 225 and 300 square feet, and the charge would be about $300 per night. He is also working to open a private rooftop lounge in addition to a lobby restaurant and bar.

Finally, he said, four residents will remain from the building’s former use as a community facility, but he indicated that they have been cooperative — in part because the construction work has not been overly intrusive.

What the developer wouldn’t reveal, despite pointed questions, was what he paid for the building. The purchase price is rumored to be about $90 million but has yet to appear in city records.

Bistricer was the second speaker at the event, following Stringer. The Manhattan borough president spoke at length about the role of community boards in development; the boards, he said, should be headed and filled by people with land-use knowledge. He worked to achieve that goal, he said, by appointing board members based on merit and not level of support for his election campaign. The results of this shift were on display in the New York University and Columbia University expansion approvals processes, which he said demonstrated how the give-and-take could work. On the other hand, he said his vote against Jamestown Properties’ Chelsea Market expansion was an example of him pushing back against a developer who appeared unwilling to consider community concerns.

“I hope [the Chelsea Market expansion] gets to a place where I can support it, but you have to use your advisory vote in a strategic way,” he said. “You say ‘no’ to send a signal to the developer to listen to the community.”

Also at the event, developer Alex Barrett, who has developed several Carroll Gardens brownstone projects, including 25 Carroll Street, said the demand for brownstone properties in Brooklyn, especially from end users, has pushed prices past the point where he can profit from renovating them. As a result, he said, he’s unexpectedly been forced to develop in Manhattan.

Finally, Brooklyn Bridge Park president Regina Myer discussed the ongoing development of that park. She updated the audience on the progress of various piers and indicated that the Starwood Capital and Toll Brothers development there would allow the park to be maintained without taxpayer funds