“You don’t see a lot of second-story restaurants,” says Adam Lowenstein. If you don’t have palpable street presence, he explains, “you have to make it a destination.”

He’s talking specifically about the restaurant above Good Time Charley’s on South U. Formerly BTB Cantina, it’s now Cantina Taqueria & Bar. (Lowenstein and Justin Herrick also own Good Time Charley’s; it shares a liquor license with the Cantina but remains a separate business and unchanged.)

Lowenstein and Herrick started BTB, then Big Ten Burrito, in 2004 on State St. to fill a need for the type of burrito joint he and Herrick knew from Santa Barbara, where they grew up. As they both matured, married, and started families, campus burritos became only one element in their complex web of independent businesses that dot Ann Arbor. Besides BTB and GTC, they also own, with partners, the Alley Bar, LIVE, and the Last Word.

BTB is inexpensive and casual. So is the Cantina, but in a more sophisticated way. The interior got a makeover from local design firm Synedoche, and new chef Magdiale Wolmark is promoting tacos made of locally sourced ingredients. Though restaurant owners generally don’t invite comparisons with other restaurants, Lowenstein doesn’t reject the suggestion that he’s aiming for something like a South U version of Adam Baru’s Isalita. Though the district has long been dominated by student eateries and drinkeries, he thinks South U has the potential to be the new Main St.: “There are plenty of people in [nearby Ann] Arbor Hills and Burns Park,” he points out, who’d welcome a convenient spot for dinner and a drink. Not to alienate his base too much, he adds: “We still have Taco Tuesday. All tacos $2.50, beer $2, and margaritas $3.”

The building is owned by old-time Ann Arborite John Carver (of the Necto) along with John and Dave Rogers. Though another student high-rise is planned behind it and yet another across the street, Lowenstein believes the building will stay (“Of course that’s a little bit conjecture. I should say, ‘as far as I know.'”)

Chef Wolmark, a lithe fifty-two-year- old with a dragon tattooed on his skull, says he learned to cook by doing it. He’s lived all over the globe, most recently owning a couple of restaurants in Columbus before moving to Ann Arbor to send his kids to the Rudolf Steiner school. Also a student of wushu, or Chinese martial arts, Wolmark says he silver medaled in tai chi at an international contest in Beijing in 2000. Among other things, he says, tai chi has “prepared me for growing older in the kitchen. I can still move around with young’uns,” he laughs. Asked to demonstrate, he gracefully tai-chis his way back into the kitchen.

Cantina Taqueria & Bar, 1140 South University, 222-3715. Lunch Mon.-Fri. 11 a.m.-2:30 p.m. Dinner/drinks Tues.-Sat. 5 p.m.-2 a.m. Closed Sun., February 26, through Sun., March 5. cantinaannarbor.com