A new concept plan for a residential development at the Center Circle site on Main Street would see roughly the same number of units but one building as opposed to three separate structures.

AST Development in August 2013 proposed three, five-story buildings totaling about 248 units but unexpected environmental cleanup became a stumbling block in the sale of the property, eventually scuttling the proposal.

Clay Bonny, managing member of East Hanover-based Heartstone Development, presented a new concept plan to the Redevelopment Agency at its Dec. 3 meeting. City Center, as it’s currently named, would include about 250 to 260 units within one building.

About 70 percent of units (~175 units) will be one-bedrooms because Bonny said they’re finding them to be more popular. Most tenants in his other buildings are young professionals, between 25 and 35 years old. Heartstone has built River Place at Rahway and Metro Rahway. Another segment of the population might be looking after an elderly parent, or a divorced man with a second bedroom as a study or room for kids visiting. “We’re seeing a major shift with young people,” he said.

A courtyard will be created within the center of the building, which will include a gazebo and pool, fire pit. Bonny said a gathering area or community room have been very popular in his other buildings.

Heartstone is finalizing the land agreement and Bonny said he wanted to make sure they were on the same page as commissioners. Heartsone briefly was involved with AST when they were working on the previous proposal. As Bonny understands it, the agency wanted a better connection between Main Street and East Milton Avenue because of the difficult parking lot. “I’m not here to be named redeveloper — maybe next month — but just here for refinement,” he told commissioners.

The project would be similar to what Heartstone has done previously (River Place at Rahway and Metro Rahway), with four stories over ground-floor parking, with about 60 to 65 units per floor.

With parking over the entire site, there would be about 275 spaces for 250 units, Bonny said, not yet at the required 1.25 spaces per unit.

“A large building is very difficult to make look good,” Bonny said, but presented an image of a Penn State residence hall that he thinks does a good job of it that could be easily adopted to this project. At one point, the agency was looking for a homogenous look for the City Hall Plaza buildings, like SDI Technologies and Meridia Water’s Edge. “We’re working hard to break up the huge facade inherent to these types of projects,” he said.

Redevelopment Director Leonard Bier said he preferred Heartsone’s finishes at River Place and less monolithic than the image Bonny presented.

The are some challenges to the project, according to Bonny, including tidal influence and grade issues. Some monitoring wells will have to stay on the site for two years, he said.

Bier questioned the size of the one-bedroom units, with a concern toward single occupancy studios. About 28 units are projected at 630 to 640 square feet, Bonny said, so they’re not quite studios but not quite one-bedrooms. The rest of the one-bedroom units are about 750 square feet and the two-bedrooms in the low 1,000 square foot range, according to Bonny, adding that the average at Metro Rahway is 1,091 square feet.

Commissioner Armando Sanchez, who lives at Meridia Water’s Edge, emphasized traffic flow in the area. “If you add more cars, traffic flow will be a disaster,” he said.