Minneapolis' renovation of Target Center, one of the more controversial facets of the Vikings stadium bill that passed the Legislature this summer, keeps getting cheaper.

The city and private stakeholders are planning to embark on a major overhaul of the 22-year-old building, made possible by stadium legislation that also provided the means to pay down debt on the facility.

When officials announced the plan in 2011, the cost was $150 million. When the Target Center "implementation committee" was formed this August, the cost was pegged at $135 million. But at the first meeting of that committee Thursday night, city officials said the working cost is now $100 million.

Asked to explain the declining cost, the city's lead staffer on the project, Jeremy Hanson Willis, said city officials are merely taking a better look at their options. Initial estimates pegged the cost for redoing the "skin" of the building at $25 million, for example.

"We thought, 'Well, maybe we don't need to spend $25 million just on the skin,'" Hanson Willis said. "And so we've been having this sort of ongoing process to say what other options do we have to do things as [inexpensively] as possible. And frankly, we're trying to get the biggest bang for our buck."

The renovation cost is expected to be split about evenly between the city and private tenants, such as the Timberwolves. The negotiations on how that deal will work are continuing.

Ted Johnson, a senior vice president for the Timberwolves, said they are in process of "sharpening our pencils."

"I don't think anyone was interested in negotiating to a number that you may not need to get to," Johnson said.

When asked about the cost during Thursday's meeting, Mayor R.T. Rybak called $100 million "a pretty good working number."

"The $150 million number was a very general, quick thing that was really -- I don't think we ever intended that to be a final or embedded number," Rybak said.

As for the other money, it's unclear where it might go. As Hanson Willis noted, "They're pretty flexible dollars."

Eric Roper • 612-673-1732 Twitter: @StribRoper