The George Lindemann Journal By George Lindemann

 George Lindemann Journal

Fort Worth, Texas

Italian architect Renzo Piano has enjoyed a career of many highs, from the 1977 Pompidou Center (with Richard Rogers ) in Paris to the opening last year of Europe's tallest tower, the Shard in London. Through his obvious skill and incomparable charm, he has also come to dominate a less enviable niche as the go-to guy for projects demanding as much deference and diplomacy as design.

Mr. Piano softened the hard white edges of the Atlanta High Museum without unduly offending the original architect, Richard Meier ; he wrapped the velveteen Italianate interiors of the beloved Morgan Library & Museum in a crisp contemporary box; at the Isabella Stewart Gardner Museum in Boston, he deployed layers and layers of glass to heighten the experience of arriving at the real heart of the place, the courtyard. Tucking turfed-over duck-blind nun's cells out of sight of Le Corbusier's sublime Ronchamp Chapel in France was the architect at his most acquiescent. Until now.

With his $135 million addition to the Kimbell Art Museum here, Mr. Piano has topped his own track record for sensitive responses to someone else's work of genius. He should stop now and concentrate exclusively on his own architecture.      

Adding to the Kimbell would rightly unnerve anyone. Designed by the American architect Louis I. Kahn and completed in 1972, it is the most universally admired modern museum building in the U.S., and equally celebrated throughout the world. (I sent an iPhone photo of just the water fountain to a European architect with no other information about my location. In a minute, he emailed back, "Must be the Kimbell.")

Beginning in the 1980s, the Kimbell could no longer easily accommodate the demands of showing both its small but choice permanent collection and temporary exhibitions. But proposals to expand by adding wings and replicating its iconic vaulting roof flamed out in the face of protests. Mr. Piano has met the space challenge by keeping his distance. The new Piano Pavilion (apparently the architect protested the honor, saying "I am not dead yet!") sits 65 yards away from the original building and adds more than 16,000 square feet of gallery space, plus an education center, 298-seat auditorium and parking garage for 135 cars.

Across a green lawn dotted symmetrically with elm trees, it stands face to face in what modernists call "dialogue" with the 1972 structure, which sits on a raised platform edged by reflecting pools. That slightly higher ground is literal as well metaphorical. The Kahn building remains as self-possessed as an oracle with its cycloid vaults rippling evenly across the roof and only breaking to form a courtyard (and light wells) and two open travertine porches of cloistered stillness.

The Piano Pavilion (designed with the Houston firm Kendall/Heaton Associates as executive architect) is the same length but two feet shorter in height and is almost invisible through the young trees from the Kahn. Both are complex poems to proportion, and trying to figure out how the overlapping double squares of the Kahn plan relate to the tripartite sections of the Piano will occupy numbers buffs for the ages. The rest of us will either feel the tension as an enhancement or restlessly compare and contrast. I fell more into the latter group.

The Kahn sits in sublime wordless serenity (Kahn himself was given to sibylline pronouncements such as "light is the giver of all presences" and material is "spent light"), while the Piano natters away. It's not so much the glass awnings at high salute over the entrance and colonnaded sides or the pairs of glued laminated timbers that overhang the walls that distract. It's the five caps at the end of every beam indicating where the supporting tension cables are anchored. The characteristically heavy stress on showing off the structural detailing may be contrapuntal to the archaic-looking simplicity of the Kahn vaults, but those five buttons come across as fussy. The lobby, otherwise vast and open, also is tricked out—with thick glass fins projecting from glass panels to enliven, unnecessarily, the view across to the Kahn building. The spacing of the floorboards may be an ingenious way to filter the flow of air throughout the galleries, but again the boardwalk look of it feels overdesigned. Both Kahn and Mr. Piano have thin glass clerestories atop gallery walls, but somehow Kahn's glow while Mr. Piano's look like the strips they are.

If the Kahn weren't there, would this be a great Piano building? Not really, as the tension I felt was not so much in the dialogue but in the sense of restraint, as of Mr. Piano holding himself back—literally, since half the building is actually bermed into the ground. His signature roof systems, which so famously allow natural light to wash evenly over space, here have a back-up of high hats on tracks to provide artificial light spots. The punch of color he sometimes applies to add a zing of heat is reduced to red seats in the auditorium. That said, the striking gallery walls made out of poured concrete work tremendously well. Not just any old mix, the concrete contains 2% titanium and has a velvety look and a magnetic blue cast especially well suited to show off the Kimbell's fine African and Asian collections.

Not that Louis Kahn made no mistakes. No lover of cars, and refusing to acknowledge that most people arrive in them, Kahn stubbornly placed the parking lot behind his building. And so visitors enter by a nondescript lower-level back door. In probably his most generous act of deference, Mr. Piano placed right in front of his own building two staircases with canted walls leading Orpheus-like up from the underground parking garage. Now, instead of his own new building, the first thing visitors will see is the Kahn as Kahn meant it to be seen.

Ms. Iovine writes about architecture for the Journal.