Five new Sandy Springs skyscrapers also means thousands more cars on local streets, a prime concern of about 45 residents and business owners who attended the first community meeting about the massive redevelopment of 1117 Perimeter Center West on Jan. 20.

Representatives of the developers—named for the first time as Hong Property Trust of Sydney, Australia—said the mixed-use nature of the project could reduce its traffic impacts. And a “direct tunnel connection” to the Sandy Springs MARTA station, which sits under part of the site, via an existing emergency exit is a major potential mitigation, said project attorney Jessica Hill.

“The idea is that it’s live, work and play, and you never have to leave,” said Rob Forrest, the Milton-based developer representing Hong Property in the deal.

But the sheer scale of the project and some of its new preliminary numbers still worried locals, especially with other major redevelopments coming nearby, such as headquarters for Mercedes-Benz USA and State Farm. The plan calls for about 1,600 residential units in three towers; about 1.5 million square feet of offices in two towers; and about 200,000 square feet of new retail and restaurant space. The towers could stand 20 to 29 stories tall. That’s in addition to the unusual hexagonal office building currently on the 13.5-acre site, which would remain with modifications.

About 5,200 new parking spaces would be created in a new deck, compared with 1,300 on site now, said Hill. Some parking might need to go off-site during construction, Hill said, though it’s early for such details. The project will be deemed a Development of Regional Impact and get a massive transportation study, said John Walker of Kimley-Horn, the traffic consulting firm hired by the developer.

One resident of Mount Vernon Woods who works at the Arby’s fast-food company headquarters next door said most of her coworkers do not use MARTA and that current traffic is already bad.

“It’s a nightmare…God forbid if it rains or snows,” she said. “As soon as [the plan] hit the papers, everybody in the [Arby’s] building across the street started freaking out.”

Bill Woulfin, CEO of Metabolic Testing Services, was among several of the existing building’s commercial tenants who expressed concerned about the plan. He said his business has been there 13 years, and he learned at the meeting of the developers’ intent to turn the first two floors into retail or service business only, meaning he would be moved elsewhere.

“That’s the first we heard of it,” Woulfin said in an interview, adding he is concerned about traffic and parking impacts on his patients.

“We want to make sure tenants stay here,” Forrest said during the meeting. “We’re very cognizant of that.”

The mixed-use concept includes street-level retail in the towers along Mount Vernon Highway, as well as a “retail alley” facing a semicircular path between the existing hexagonal building and the new towers.

The existing building will get a “significant facelift” that is already underway, Forrest said. That includes cutting three new entrances into its central courtyard. That courtyard is current private but will be opened to the public and possibly host concerts or performances, Forrest said. He said that Hong Property wanted to keep the building because of its unusual charm and potential as an attractive retail and restaurant spot.

Because the meeting, held at the existing Perimeter Center West office building, was a preliminary review required before filing actual plans, few other details were available. Hill said the filing should happen next month, with the DRI and Sandy Springs city zoning reviews running into the fall. The developers will seek rezoning from office to mixed-use and anticipate variances for excessive height and less parking that is usually required because of the proximity to MARTA.

Updated: A previous version of this story gave an incorrect name for the trust that purchased the property.