For years, University of Alabama at Birmingham athletic director Mark Ingram wondered whether a football team in the South could build an indoor facility without walls. So as UAB explored an indoor field for its return to football in 2017, Ingram asked a friend who's an architect if the idea is doable or just a ridiculous thought.

"It's just like throwing the ball on fourth and short," Ingram said. "It's brilliant if it works, but if not, you're an idiot."

It's possible, and it's happening at UAB, which is breaking ground this month on what may be major college football's first "indoor" practice facility that's not actually enclosed. Ingram knows no other schools that have done this. UAB is putting a pavilion roof over a 100-yard field without climate-controlled walls.

UAB's 'pavilion' will be one of the most unique in college football. UAB

UAB will pay $4.7 million for the pavilion instead of about $15 million for a regular indoor facility, Ingram said. Since walls don't need to be built, UAB will save significant money by not paying for windows, doors, air conditioning, a fire and sprinkler system, and additional lighting that would be needed for a truly enclosed indoor field.

"If it's raining, the field is dry. If it's hot, you're under shade," Ingram said. "So what do we need the walls for? At the end of the day, what are we talking about? It doesn't get cold here.

"I was at Tennessee for 15 to 16 years and it gets reasonably cold there in the winter, and that's only four hours north (of Birmingham) but it's a higher elevation. I can see why Tennessee wants it. Now, they don't have air conditioning in theirs. It would be hard here to explain why you didn't have air conditioning. But we'll be able to save a lot of costs. And we're getting what we want."

In recent years, football programs across the country have built indoor facilities in increasing numbers. Florida just built a $15 million indoor field ahead of the 2015 season. Georgia is building an indoor facility for about $30 million.

But that's a lot of money for a Group of Five school such as UAB, whose entire athletic department budget is roughly the same as what Georgia will pay for its indoor field. The University of Alabama System approved UAB for $22.5 million in new football facilities. The wall-less indoor field stretches out the Blazers' money for other improvements.

"This was the most economic way," UAB coach Bill Clark said. "Most people have a second or third gym on campus. Our second gym here is a [physical education] facility. Not only is volleyball or other sports in there, you have actual PE classes there. So you're nice to the people who run it. You try to get it when it rains, but they have PE classes going on."

UAB's pavilion won't initially have fans to help with heat. Clark said he might wall the facility if enough money eventually gets raised.

Ingram used to be senior associate athletic director at Temple, which has an indoor field that's entirely enclosed. He recalled seeing Owls players often running outside during Philadelphia winters.

"It doesn't get that cold in the winter here (in Birmingham)," Ingram said. "If we need to, can we put on a long-sleeve T-shirt? Is it really that hard?"

When UAB shut down football in 2014, the university said it was due to a lack of money. Now as the Blazers return, they may be giving other schools a new blueprint for how to hold "indoor" practice, economically.