For six years, plans to transform land next to the New Jersey Performing Arts Center in Newark existed only in architectural renderings, a tabletop 3-D model and tales told in rarefied circles by the center’s president, John Schreiber.

The goal was lofty: NJPAC, a nonprofit, would build retail space and hundreds of market-rate apartments, reinvigorating a dilapidated business district and spinning off enough profit to shore up its bottom line and reinvest in arts programming.

The pandemic delayed the dream. Then a hot real estate market and a newly generous state tax incentive program accelerated it.

On Wednesday, New Jersey officials will celebrate the groundbreaking of the $336 million project, which, within three years, is expected to alter the skyline of the state’s largest city and turn a ribbon of land next to a traffic-choked highway into an arts and retail hub.

The project, known as ArtSide, is one of the largest real estate ventures in decades in Newark, a poor industrial city 14 miles from Manhattan that is struggling to revitalize without large-scale gentrification.

Hopes are high. “It’s massive,” said Ras J. Baraka, the city’s mayor. “It helps us to change the center of gravity in Newark.”