The San Diego Chargers, who were in serious negotiations to relocate to Los Angeles with the Oakland Raiders and share a stadium, released renderings of a proposed $1.8 billion stadium and convention center expansion in San Diego.

The stadium would have 61,500 seats that would expand by 10,500 seats to accommodate a possible Super Bowl, the San Diego Union-Tribune reported. With a retractable roof, San Diego could convert the stadium’s 100,000-square-foot playing surface as column-free convention center space. The roof also would allow the city to host events such as the NCAA Men’s Final Four and WWE WrestleMania but would prohibit natural grass.

“It’s a compromise,” Jeffrey Pollack, a special advisor to the Chargers, told the newspaper. “But it’s the direction we’re headed so this project can really serve the community for more than 10 days a year.”

Kansas City-based Manica Architecture, the same firm that designed the proposed Carson, Calif., stadium project for the Chargers and Raiders as well as London’s Wembley Stadium, produced the renderings for the proposed San Diego stadium, USA Today reported. The proposed Chargers stadium would be more intimate for fans than other stadiums, according to the Union-Tribune:

Architect David Manica said the seats will be “as low and tight to the field as possible,” and the distance between the edge of the playing field and first row of seats will be the minimum allowed by the NFL. Mata said the proposed stadium is “much lower than most of the other recently constructed stadiums with retractable roofs (by) four to six stories.”

The Chargers and the National Football League are pledging $650 million toward the cost of the stadium. The rest of the $1.15 billion is expected to come from public financing covered in part by a 4 percent net increase to the hotel tax that would bring the tax to 16.5 percent, the Union-Tribune reported.

Chargers quarterback Philip Rivers, former Charger and future Hall of Famer LaDainian Tomlinson, NFL commissioner Roger Goodell and Chargers chairman Dean Spanos are scheduled to appear at a signature-gathering pep rally on Saturday to get a stadium vote on the Nov. 8 ballot. About 67,000 signatures are required by June 8 to qualify for the ballot, the newspaper reported.

Last month, the chairwoman of the San Diego Convention Corp. said the proposed annex of the convention center in the new Chargers stadium plans would not meet its needs for additional exhibit space to help keep Comic-Con International and continue to attract other large trade shows. Others on the San Diego City Council are concerned over the potential effects of the proposed hotel tax hike.

“Counting on a significant tax increase to fund the construction of this plan, while also reducing marketing and promotional investments, will affect our ability to compete with other markets for tourists and conventions,” Councilman Chris Cate told the Seaside Courier. “Realistically, as the third largest source of revenue for our city, any potential negative impact to this funding source, no matter how minimal, could impact our ability to pay for police services or pave our streets.”

The Athletic Business Show was last held at the San Diego Convention Center in 2013. The International Health, Racquet and Sportsclub Association (IHRSA) is scheduled to hold its annual convention and trade show in San Diego in 2018.