After months of talk, it’s official: The Roundabout Theater Company has sealed the deal with Gotham real estate company the Durst Organization and Bank of America to program the new incarnation of Henry Miller’s Theater, which will open in the fall with the Roundabout’s upcoming revival of “Bye Bye Birdie.”

The Henry Miller’s — an entirely new Broadway auditorium constructed behind the original 1918 facade of the old theater — is the first Rialto house built to green standards, with environmentally minded elements including waterless urinals, an air filtration rate of 95%, wall panels and baseboards made with a high percentage of recycled content, and locally sourced marble.

The Broadway venue, located on West 43rd Street near Times Square, will have 1,055 seats. Mezzanine will be at ground level, with the patrons descending to the orchestra.

With the deal, the finances of which were not disclosed, the theater becomes the third Broadway space to be operated by the Roundabout, following the American Airlines Theater and Studio 54. The addition marks a gutsy move in a rough economic climate that has nonprofit theater companies all over the country tightening their belts.

Roundabout previously produced its hit revival of “Cabaret” in the old Henry Miller’s. Douglas Durst, head of the Durst Org, sits on the Roundabout’s board. A third space for the Gotham nonprofit has long been discussed as a potential venue for hit productions that could sustain longer runs, such as the company’s popular stagings of “Cabaret” or “The Pajama Game.”

The last Broadway offering to play the old Henry Miller’s Theater was “Urinetown.” The theater was shut down in 2004, when construction began on the One Bryant Park Project, including Bank of America Tower, which houses the new Miller’s and is a joint project of Durst and Bank of America.

Cook+Fox Architects, preservationists Higgins & Quasebarth, consultant Fisher Dachs Associates and Jaffe Holden Acoustics, were among the groups involved in the design and construction of the project.

Although the Henry Miller’s Theater looks ripe for a lucrative corporate branding deal, a la the Roundabout’s American Airlines theater, no plans for a name change have been announced.

“Birdie” — the first Rialto revival of the show since its 1960 preem — begins perfs Sept. 10, with helmer Robert Longbottom directing a cast that includes John Stamos, Gina Gershon and Bill Irwin. Opening night is set for Oct. 15.