The two players involved, GM and Gilbert’s Bedrock, can be patient in seeking the right mix of uses — although they plan to work quickly.

“Our plan is to stick to that date and our plan is to work as quickly and expeditiously as we can,” Massaron said.

The ultimate final mix could involve converting some of the buildings to residential space — a costly proposition to begin with, but one that has become more popular during the COVID-19 pandemic — or commercial space, or some other mix of uses.

The RenCen towers could also remain office space if the right user or users are attracted. Demolition could be a possibility, freeing up prime Detroit riverfront land, although Massaron said “the focus is on planning for redevelopment.”

“That’s what we are geared toward, and that’s what our orientation is,” he said. 

Precisely how much space GM is taking in Hudson’s Detroit is not known. Massaron said the deal was finalized Monday, although the arrangement allows for flexibility in the footprint.

“We are thrilled to have GM moving to Hudson’s,” said David Di Rita, principal of Detroit-based The Roxbury Group, a major development company in the city that has several properties near the Hudson’s site. “They have been a key player in the revitalization of downtown for nearly 30 years now and their relocation to the Lower Woodward corridor will have a major positive impact on the continuing growth of the district.”

Depending on the outcome of the RenCen discussions, public dollars could be involved. 

Massaron said it’s too early to discuss what, if any, would be sought. But a redevelopment project of that scale could revolve around millions in incentives, ranging from tax abatements to transformational brownfield funding.

Eric Larson, president and CEO of the Downtown Detroit Partnership, called the Monday news “a very exciting development” for the city and one that’s good for Detroit, GM and Bedrock.

Matt Cullen, a former GM and Bedrock executive who has been involved in the discussions, said conversations about GM about taking space in Hudson’s Detroit go back years, although the most recent incarnation goes back about a year.”

Cullen is also head of Jack Entertainment and board chair for the Detroit Riverfront Conservancy. “It’s a big day,” Cullen said following the announcement.

GM CEO Mary Barra, in response to reporters’ questions about potentially selling the RenCen, said the automaker is “working to decide what the right outcome is for the building.”

“We are embarking on taking the next year to work together with the mayor, Wayne County and Bedrock to imagine what it can be,” Barra said.

There have previously been conversations between Gilbert and GM about purchasing the riverfront complex, although those fizzled prior to the start of the pandemic in spring 2020.

Mayor Mike Duggan told reporters following the event that he is “totally open minded” about the Renaissance Center’s future.

He pointed to what he described as an “enormous demand for housing” but also noted that a redevelopment into that kind of space would be expensive. He also pointed to other potential uses that could be in the mix.

He also noted Gilbert’s history of finding new uses for old, iconic properties around downtown.

“Nobody has repurposed buildings more than Dan Gilbert,” Duggan said.  

The seven-building RenCen complex was built in 1973 and includes four office towers surrounding a Marriott hotel tower, as well as two smaller office towers. GM has used the office towers surrounding the Marriott tower as its headquarters since 1996, when it bought that part of the complex for $73 million. Since then, GM has invested more than $1 billion in the building and surrounding Detroit RiverWalk. 

The two smaller office towers  — the 500 and 600 buildings — on the east end of the property were sold late last year to Farmington Hills-based Friedman Real Estate.