The entire seventh and eighth floors of the former vocational high school were sealed off for decades before the school closed (due to fire code violations) and were reopened by its current owners (now with a proper sprinkler system). Irwin’s occupies the more spacious room on the south side of the building, and the bones of this former nursing classroom proved to be a ready stage for designer Kate Rohrer of Rohe Creative to craft a seductive, edgy space. The white-tiled walls were left as-is, still amply tagged with graffiti. Paint is still chipping off the concrete ceilings. But with vintage rugs on the floor, a shelving unit from the old chemistry lab repurposed as the bar, cushy leather banquettes, a dramatic gold curtain, big communal tables relocated from the art room, plush club chairs and potted palms now framing the expansive view of South Philly and its stadium lights, the mood for transformation has been set. And the largely youthful crowd has embraced it — some at the table behind us toting their post-workout yoga mats — eager for rooftop libations and mezze.