Congress is set to spend at least $550 million on a multi-year renovation of the historic Cannon House Office Building, but taxpayers may never know more than the most rudimentary details about the contract for the massive project.

A partnership created by a Michigan firm and another in Maryland won the contract, which is being managed by the Architect of the Capitol (AoC), according to The Hill, which first reported the story.

"The contract, awarded on Oct. 31 to a partnership between Maryland-based Clark Construction and Michigan-based Christman Construction, is scheduled to last through 2025, with the next two years devoted solely to planning, according to the pre-solicitation contract posted on the General Services Administration (GSA) website," the publication said.

The Cannon building was constructed 105 years ago as the first free-standing congressional office building. It is named after House Speaker Joseph Cannon, who led the House from 1903 to 1911 and exercised an unmatched degree of control of the proceedings. He was an Illinois Republican and became the first Member of Congress from either major political party to serve more than 40 years in Congress.

The projected cost of the project and its complexity are already sparking comparisons to the Capitol Visitors Center (CVC), another recently completed congressional construction project that failed to make deadlines and proved far more expensive than originally planned.

"The CVC was completed years later than planned and more than $350 million over budget," according to The Hill. "The ballooning costs and delays occurred due in part to changes to fire and safety elements that needed to be made after construction had begun."

For more from The Hill, go here.