After months of delays, the Park Slope Armory is finally open for business — and recreation.

The YMCA-run, $16 million center celebrated its grand opening on Jan. 11, and will be open to the public on Jan. 30.

The spectacular 100,000 square-foot facility was expected to open earlier this fall, but renovation of 20,000 feet of classroom space was not completed yet, frustrating those itching to get a crack at its state-of-the-art track-and-field center and basketball courts. A host of programs are eventually planned in the classroom space.

Sean Andrews, the executive director of the Prospect Park Y has said he understands community frustration about the delay, but that the end result will be an exciting venue.

The YMCA was selected last year to operate the recreational portion of the facility through a competitive RFP (Request for Proposals) submitted by the city’s Department of Homeless Services. The agency will continue to maintain a small women’s shelter in the building, located at 1402 Eighth Avenue.

e_SDLqThe fact that the Y is managing the facility is fantastic for us because they brought a lot to the table — they already have close ties to the community and a wonderful local track-record as a quality organization,” said Community Board 6 District Manager Craig Hammerman. Hammerman and others have been critical with the path the armory followed from its design to its creation, saying little community input was ever sought. “Because of how the city skirted various review processes to open this facility we aren’t sure what options exist for preserving the public interest moving forward,” he said.

In June, the Y finalized a 10-year contract with the city. Primary revenue will come from individual membership fees, $40 a month for adults an $72 for families. The facility will also offer fee-based programs such as summer camp and after-school programs. No one will be turned away based on their ability to pay for membership, Andrews has vowed.