While a potential move to suburban Arlington Heights for the Bears has repeatedly been teased, the city is now considering the viability of putting a dome over Soldier Field in an effort to make the stadium more attractive.

The dome, as reported by Crain’s Chicago Business, could cost between $400M and $1.5B and will require some sort of taxpayer subsidy, according to a draft of an upcoming report by Mayor Lori Lightfoot’s Lakefront Museum Campus Working Group.

The panel has also proposed a number of additional upgrades, from rebuilding parts of the stadium to selling naming rights in order to generate revenue for further improvements.

While the dome might seem like a last-ditch effort by Lightfoot to keep the Bears in Downtown Chicago, the proposal is also part of a broader effort by the city to drum up tourism and attract more major musicians seeking concert venues.

“To better utilize Soldier Field year-round, the working group recommends the city explore the feasibility of enclosing the stadium,” the report says. “Although an enclosed venue is unlikely to attract many more major concerts due to limited touring windows, among other reasons, it would negate inconsistent weather conditions and allow Chicago to host coveted one-time events.”

However extensive these plans may be, the team hasn’t been in these discussions. While the Bears have a lease at Soldier Field that runs through 2033, the team has put its focus on a pending purchase for a possible new home in Arlington Heights — a deal that is highly likely, but not expected to close until next year.