The Vikings’ lease at the Dome ends in 2011, and the commission (Metropolitan Sports Facilities Commission), which owns and operates the facility, believes it needs to break ground on a new multipurpose stadium within the next 18 months to complete it in time for the 2012 season.

The Ellerbe proposal was prepared and supposed to be unveiled last summer, in late July or early August, but the 35W bridge collapse put that on hold, Terwilliger said Thursday.

What makes the Ellerbe idea different is that it would reuse some of the original Metrodome foundation as part of the new structure, as well as some of the seating bowl.

But Terwilliger said that almost the entire stadium would be new, with wider concourses, thousands of new seats, more suites and state-of-the-art features throughout. The new facility would bring in about $32 million in additional revenue per year, the commission said.