A mini-city slated for the site of a shuttered General Motors plant — one of metro Atlanta’s largest redevelopment efforts — is finally coming into full view.

The mixed-used project known as Assembly will soon welcome its first company to occupy space on the 165-acre campus. In the next few weeks, Serta Simmons Bedding is set to move in, consolidating its headquarters and bringing more than 500 employees.

Eventually, The Integral Group, the developer of the property, hopes to show off 750 multifamily housing units and 300,000 square feet of office space over the next two years. Assembly aims to support about 15,000 jobs.

“We’re pleased to say that really, it’s a culmination,” said Matt Samuelson, the chief operating officer of the commercial real estate division for The Integral Group. “We’ve been hard at work and a lot’s already been accomplished.”

The former GM assembly plant near Peachtree Road and I-285 was founded in 1947 and eventually had 4,000 employees spread over a plot of land the size of 125 football fields. It shut down in 2008, at the height of the recession, and the land has generally remained dormant since then.

This map shows what the Assembly Yards development will look like. (Photo courtesy of The Integral Group)

icon to expand image

Doraville, a DeKalb County city that straddles I-285 just north of the I-85 interchange, worked for years to attract the right development at the site. At one point, the space was even seen as a potential location for the new Atlanta Falcons stadium, The Atlanta Journal-Constitution reported in 2014.

When The Integral Group purchased the land in 2014, they were fifth in a line of developers that tried to tackle the vast plot of land, Samuelson said.

“It has been almost 11 years since GM closed its doors, so suffice it to say, we’re thrilled” for Serta Simmons to move in, Doraville Mayor Donna Pittman said in a statement.

“We always envisioned and planned for a site predicated on regional job growth, so we view the Serta Simmons relocation as a catalyst,” Pittman said.

Serta Simmons Bedding's new headquarters is set to open in early April in Doraville.  (Photo: Curtis Compton / ccompton@ajc.com)

icon to expand image

Prior developers were more focused on finding a major company to anchor and carry the initial redevelopment from the start of the project. Samuelson said Assembly set out to create a transportation-focused, mixed-use space that would attract companies on its own.

“We decided instead to create a city within a city,” Samuelson said, “and allow the users to come.”

Over the past four years, they demolished 3.5 million square feet of the vacant buildings and got to work implementing 550,000 square feet of development.

The project will also include parks and retail areas. The Doraville City Council voted earlier this year to allow open containers of alcohol in parts of the district to encourage entertainment and foot traffic. Third Rail Studios, a film and production company, has had a location at the site since 2016.

The developers strived to make Assembly a hub focused on transportation and accessibility, since it’s “in a strategic location to restitch the fabric of connective transportation options,” Samuelson said.

It sits right off I-285, near Buford Highway, Peachtree Road and the I-85 interchange. The Doraville MARTA stop is nearby, and the DeKalb-Peachtree Airport is just a few miles away. To help residents and workers get around the sprawling area, The Integral Group last week announced plans to buy a self-driving shuttle that would operate at Assembly.

“We hope it becomes a place that many in the Atlanta metro area will come to enjoy,” Samuelson said.

The project wasn’t always smooth sailing, though. At one point, it was in jeopardy as The Integral Group looked to local government for crucial investment help. The city of Doraville and the DeKalb County commission voted to spend $200 million in tax allocation district funds, but developers were never able to get the DeKalb County School District to commit to help finance the project.

A worker on a lift outside the new Serta Simmons Bedding building overlooks the Assembly development, a mini-city slated for the site of the old General Motors plant. (Photo: Curtis Compton / ccompton@ajc.com)

icon to expand image

Instead, the redevelopment forged forward with a complex tax incentives arrangement that amounts to 35 percent of the site’s annual property tax bill for the next 30 years.

Samuelson said the development was a result of “fantastic partnerships at all levels.”

Serta Simmons, the nation’s largest mattress company, announced its headquarters relocation in 2017, and will move in beginning in early April. Most of the employees coming to the new 250,000-square-foot office building are already working in the Atlanta area at other Serta offices: the current corporate headquarters in Buckhead, Beautyrest brand offices in Dunwoody and a research and innovation center in Norcross. The company also offered jobs in Doraville to 120 employees from the Serta brand offices in Hoffman Estates, Ill.

A DeKalb County city could soon take a big step towards bringing driverless shuttles into the area.

After the Serta team moves in, officials at Assembly hope they will be able to make use of the free self-driving shuttle. The shuttle, built by NAVYA, will arrive in early April and will be the first of its kind for a mixed-use development in the Southeast.

Beginning this summer, it will carry people who work at Assembly to and from the Doraville MARTA station, about a half-mile trek. It will only be used on-site until Doraville and Chamblee’s public roads have the infrastructure to support autonomous vehicles, Samuelson said.

Over the next two years, the site plans to work on the residential units and other amenities, including 125,000 square feet of food and entertainment retail space. As for other companies that might use the space, developers said it’s too early to release names.

Follow DeKalb County News on Facebook and Twitter