[Kimbell site plan (click for expanded image) | image provided by Kimbell Art Museum | © Renzo Piano Workshop]
In addition to the Kimbell in Fort Worth, Texas...
[Kimbell section (click for expanded image) | image provided by Kimbell Art Museum | © Renzo Piano Workshop]
...is Piano's controversial (PDF link) visitor center next to Le Corbusier's Notre Dame du Haut in Ronchamp, France...
[Notre Dame du Haut visitor center | image source]
...his unrealized addition to Marcel Breuer's Whitney Museum of American Art in New York...
[Whitney Museum expansion | image source]
...and finally his addition to Richard Meier's High Museum of Art in Atlanta, Georgia, which opened in 2005.
[High Museum expansion | image source]
I would argue that Piano's treatment of the vertical and the horizontal, the facade and the roof, is a formal reason for his position as the "go-to guy" for these sorts of commissions. Specifically by focusing focus on the overhead plane, most often in the form of innovative skylights, the relatively windowless facade is able to drop into the background, much like Gwathmy Siegel's extension of the Guggenheim, which didn't even try to compete with Frank Lloyd Wright's swirling masterpiece. This is surely the case with the High Museum, and the Whitney facade is a lesson in restraint, but the two latest designs for the Kimbell and Ronchamp attempt to use the landscape to "blend" into their context. In the case of the former the landscape berms over the partially underground, Nasher-esque building, while in the latter case the visitor center would be built into the hillside to be hidden from the chapel above. Of the two the Kimbell has the best chance of being realized, so I'm looking forward to seeing more fleshed-out images that give a stronger impression of the formal relationship between old and new.