In 2011, the venerable downtown Austin club Stubb’s asked architect Burton Baldridge to turn a decrepit trailer it owned into a green room. Then, after some initial deadlines came and went, the bar’s brass called to say they would need the new lounge by the time the first group took the stage at the Austin City Limits Festival—just three weeks away in the middle of the hottest summer in Austin’s history.

Stubb’s—with its outdoor and indoor stages and a barbecue restaurant—is housed in a 19th-century building that just happens to sit in a floodplain. So any changes to the existing green room setup would mean either meeting 21st-century building codes or creating a temporary structure. “That doesn’t mean the green room has to be easy to move, it just has to be able to,” Baldridge says. The 31-foot 1970s Airstream with a rotten floor would have to do.

Baldridge teamed up with fellow Austinite Branson Fustes of Pilgrim Building Company to cover the interior walls with long strips of mahogany veneer that would show off the trailer’s retro curves. They also built a bar in one end, secured a flat-screen TV to one wall, and lined the other with two narrow couches.

But Baldridge’s most impressive architectural move is the arresting new doorway. “I hated having to crouch down to walk inside an Airstream,” he says. So his team took out the original door and cut a six-by-six-foot square in the side of the trailer. Using quarter-inch plate steel, they built a commanding entryway with a door made out of tempered glass, which lets in daylight and helps the small interior feel less cramped.

The new doorframe was so heavy that when Baldridge and his crew towed the trailer to Stubb’s he feared it might roll over. “I was even more worried about the crane,” he says, which lifted the Airstream from the street, over the building, and into the patio behind the outdoor stage. But that maneuver too went without major incident.

As directed, construction finished just before global superstar Manu Chao was scheduled to arrive. “We were sweeping it out at 4:45 p.m.,” says Fustes, “and the band was supposed to walk in at 5.”