Mid-century modern designs with history and surprises.

DETROIT – Outside general motorsAt the new world headquarters, between the 12-story building and the city's first new skyscraper in more than 30 years, sit two red Chevrolet pickup trucks.

One is a 1963 Chevrolet K20. The other is a new Silverado EV. The trucks, while part of a temporary Christmas display, are a symbol of what's inside the Detroit automaker's new global offices: its past and present, intertwined.

GM occupies four of the building's six office floors and has filled them with artifacts, design nods and “Easter eggs” tied to the Detroit automaker's history.

They range from a floor plan of GM's iconic design dome and an early map of its nearby proving grounds to interior wallpaper featuring 300 patented technologies and a feature wall of cassette tapes featuring songs featuring the automaker's brands, as well as playful references to executive stalwarts like CEO Mary Barra and Chairman Mark Reuss.

“When we were helping design the space, leaders asked to incorporate some Easter eggs and details to represent who we are at GM, you know, honor our culture, our history and our innovation,” Rebecca Waldmeir, GM's manager of industrial design architecture and experience, told CNBC during a tour of the new headquarters.

Other surprises include references to relevant Detroit streets, design influences from GM's famous design campus in suburban Detroit, and artwork and sculptures of its products.

Aesthetics aside, GM officials say the new offices will help with collaboration and are more relevant to how the company expects its employees to work in a post-pandemic world. It will house executive offices and other corporate functions such as marketing, legal and finance.

“A headquarters really should be, on some level, a beacon for the company's culture,” said David Massaron, GM's vice president of infrastructure and corporate citizenship. “When you come here, you should help people understand who we want to be.”

The new headquarters marks a major reduction in square footage for the automaker's corporate office: from a towering complex called the Renaissance Center along the city's riverfront to just four stories, about 200,000 square feet, in the new building.

GM's new headquarters is less than a mile from the RenCen, as it is commonly called, which has been a landmark for the city since, ironically, Ford engine It built the complex but decided not to make it its headquarters in the 1970s. GM purchased the building in 1996 as its third headquarters, all of which have been in the Motor City.

RenCen is Detroit's fortress, a 5.6 million-square-foot complex complete with a 700-plus-foot central tower surrounded by four 500-foot towers and two smaller adjacent ones.

It is notoriously difficult to enter and exit the complex and navigate. For much of its existence, it was surrounded by concrete barriers before a redesign around the turn of the millennium.

It has long been something of a physical permutation of GM's historically insular culture, changing which for Barra has been a priority during her roughly 11 years as CEO.

“The RenCen was designed in a different era, in a pre-Covid era, where everyone was going to work five days a week, everyone was going to their desk,” Massaron said. “Particularly in a post-pandemic world, you need office spaces that people want to come to, because we have options.”

GM's roughly 50,000 salaried employees in the United States currently must work in the office Tuesdays through Thursdays, but the rules are more flexible than before on location and remote work.

Most of the company's new executive offices on the top floor of the building will be open for executives to use as they wish, Massaron said. Only four of the offices will be permanently assigned to top GM executives, like Barra and Reuss, he said.

GM declined to reveal how many employees are expected to work regularly at the new headquarters, saying foot traffic will fluctuate depending on priorities and work flows. The company also declined to disclose financial details of its 15-year lease at the new headquarters.

The building complex, known as Hudson's Detroit, is owned by a real estate company from rocket companies President and billionaire Dan Gilbert, who has been buying and renovating properties in Detroit for more than a decade.

In addition to the office areas and executive floor, which open onto an open atrium, GM also plans to open a semi-public space to showcase products and host events on the first floor of the building.

Other amenities include social gathering areas and lounges, food and beverage services, and a pickleball court and recreation area.

GM's new headquarters, which is still under construction, comes months after Ford christened a new 2.1 million-square-foot global headquarters and product design and development center in nearby Dearborn, Michigan.

Ford's new facility includes offices, industrial and design operations and a host of amenities such as a 160,000-square-foot dining area with eight “kitchen concepts,” multiple patios and other improvements.

The notable difference in size between GM and Ford's new headquarters comes down to the automakers' location, workforce, and office and operations portfolios across the region.

GM, for example, has a vast technology and design center occupying 710 acres in nearby Warren, Michigan. That campus is home to more than 24,000 employees.

Massaron said GM did not feel the need to create “a city within a city” for its new headquarters, because it is actually “a building within a city.”

Here's a look inside GM's new world headquarters: