Seated gracefully on the floor near the footlights, dancer Mackenzie Dessens watched this week as fellow members of Delta Festival Ballet rehearsed on the brand-new stage at the Jefferson Performing Arts Center.

Plaques were still being hung in the lobby, and final touches had just been completed on the landscaping outside the long-awaited building at 6400 Airline Highway in Metairie next to Zephyr Field.

But inside, the dancers were practicing for the grand-opening gala Saturday night, accompanied by the Jefferson Performing Arts Society orchestra.

“The floor is perfect,” Dessens, 20, said approvingly, adding that it was her first time on the stage. And the theater, with just over 1,000 upholstered red seats ranging up toward the ceiling, was larger than she expected. “I was surprised,” she said.

Officials held an open house Thursday to show off the $54.5 million building.

Beset by problems over the 15 years it took to build, the project was delayed repeatedly and cost the state and parish more than double its initial budget.

But General Manager Jose Torres this week was ready to look forward, pointing out the state-of-the-art acoustics in the theater, the clear sightlines from every corner of the theater and the soaring system of pulleys, riggings and catwalks backstage.

With high ceilings and wide windows overlooking LaSalle Park, the 86,000-square-foot building accommodates a 61-by-40-foot stage, 10 dressing rooms and a green room.

The gala on Saturday will feature the Branford Marsalis and Joey Calderazzo Duo.

The resident Jefferson Performing Arts Society orchestra, conducted by Dennis Assaf, will open the gala show, and members of Delta Festival Ballet will perform.

Posters in the box office windows promote upcoming shows. The first is the musical “My Fair Lady,” opening Sept. 24.

The center is managed by SMG, which also manages the Smoothie King Center and the Mercedes-Benz Superdome, and is suitable for all kinds of events, including traveling shows, recitals and graduations, Torres said.

The space is meant to accommodate all ages and interests in the increasingly diverse community.

“This is about expanding the arts in Jefferson Parish,” he said.

The state-of-the-art facility is complete, Torres said.

“We’re done. We’re ready to do a show. Our box office is ready and running; our staff is in place,” he said.

“It’s finally here.”