The St. Louis Rams' plan to improve the Edward Jones Dome calls for a roof panel that would open slightly to allow more natural light.
Missouri Attorney General Chris Koster released details of the plan Monday despite the team's desire to keep it private.
The team's proposal does not cite a cost estimate. It also calls for adding about 6,000 seats.
The Rams and the St. Louis Convention and Visitors Commission are negotiating to try and improve the dome. If no deal is reached, the Rams could potentially break the lease and move after the 2014 season.
A sketch provided with the plan shows that the roof panel would not retract to expose the entire field but would open enough to allow natural light on game days.