In one of the biggest corporate relocations in the Twin Cities this year, TCF Financial Corp. has started moving 1,700 people from its downtown Minneapolis tower and other offices to a remodeled office building in Plymouth.

Its first challenge: how to get people there every day.

While the two-story building is surrounded by acres of parking, many of its workers had become accustomed to using public transportation in and out of downtown.

"We heard a lot of comments about that," Barbara Shaw, TCF's director of human resources, said Tuesday on a media tour of the new site. "We couldn't meet all needs, but we now have an express route from downtown Minneapolis."

This new bus route, run by the city of Plymouth's Metrolink transit service, is designed for commuters coming out of the city in the ­morning and heading back in at night, Shaw said.

The city has opened three daily express trips between downtown Minneapolis and the company's new address, 1405 Xenium Lane N., and Plymouth Mayor Kelli Slavik said the city will reassess demand once all the employees arrive.

While 200 workers have already moved, the relocation kicks into high gear in August when workers from seven offices move to the 400,000-square-foot building, which was built in the 1970s and expanded in the 1990s.

The last downtown Minneapolis employees — apart from those operating a bank branch on the skyway level of the IDS building — will move in November, ending the company's nearly 100-year presence in the city's core.

TCF, which has had a corporate presence downtown since it was founded in 1923 as the Twin City Building and Loan Association, is vacating its namesake 17-story tower at 121 S. 8th St. and the podium-style bank building next door.

Doing so will produce enormous savings for the company, which is Minnesota's third-largest bank by deposits. The Plymouth office space leases for $16 per square foot, well below the $22 per square foot it pays in the TCF Tower.

To make it work, the remodeling of the Plymouth building had to include conveniences that employees have come to expect downtown.

"It really became second-nature for those downtown to do all their errands nearby," said Craig Dahl, TCF's vice chairman and president. "We think we can accomplish a lot of the look and feel of downtown but in the suburbs."

The new office includes a fitness center, a convenience store with dry-cleaning services, a cafeteria, bike storage, showers and a day care center next door.

The move gave TCF a blank slate to design a more open floor plan for employees and provide new workstations with the latest options, such as standing desks. Bringing all the employees in proximity to each other in one location will also benefit the company's work, Dahl said.

"If we were to bring all these people downtown, we would end up with multiple floors and people trying to collaborate would have to get on a elevators," he said. "One of the appeals is being only on two floors."

This move marks the final step in the exodus of TCF's corporate offices from Minneapolis. Chairman William Cooper and other executives shifted the corporate headquarters to Wayzata in 1997 and, 12 years later, moved the bank's legal headquarters to Sioux Falls, S.D.

The fate of the TCF Tower and adjacent bank building remain uncertain. Both are owned by a Boston-based real estate investment company, Franklin Street Properties Corp., and are managed by Minneapolis-based Ryan Cos. News of its anchor tenant's departure last spring led to discussions about a possible redevelopment effort, but nothing has been announced.

Kristen Leigh Painter • 612-673-4767