Wednesday, November 27, is the day when we’ll witness part two of a worldwide architectural story that began in 1972 with the opening of Louis Kahn’s immortal Kimbell Art Museum in Fort Worth — a concrete, travertine and glass masterpiece for the ages. With the unveiling of the Piano Pavilion at the Kimbell, another architect has dared challenge Kahn: Genoa-, Paris- and NYC-based Renzo Piano Building Workshop, in association with executive architect Kendall/Heaton Associates, Inc., of Houston. Our eyes (and feet) will be on the grass roof of the pavilion’s submerged west wing, a 19,200-square-foot green berm upon which to stroll, as well as the verdant landscape redux that adds 320 trees to the 3.5-acre campus. The entrance of the museum will now be towards the west in keeping with Kahn’s original vision. Plans call for moving/reinstalling treasures from the Kimbell’s permanent collection — its jewel-box holdings of Asian, African and pre-Columbian art as well as temporary exhibitions — into the new Piano Pavilion. For acolytes of architecture, the Kimbell addition, Piano’s fourth museum in Texas, will be on pilgrimage routes for decades to come. kimbellart.org.