The San Diego Chargers NFL team wants a new stadium, and the city's convention center wants to expand. If the projects were combined to create a dual-use facility, the city could save 25% on the $1.6 billion cost of building two separate structures. "And what if, to be very simple ... you put a roof and a floor on a stadium, neither of which we have now?" asked San Diego Mayor Bob Filner. "You could have concert venues with a roof and other things. With a floor, you can play hockey and soccer, basketball."