John Russell Pope’s original National Gallery of Art is one of the world’s greatest museum buildings, and only gets better with age. Not only does every exhibition look magnificent in the top-lit galleries, but the gleaming marble exterior shimmers throughout the day, dominating the mall with its quiet monumentality. When I.M. Pei added his vaunted East Wing in the 1970s, critics were quick to compare its angled, abstract surfaces with those of the Pope building. I have never been impressed with the East Wing, either as a compelling museum interior or as a monument worthy of a place on the mall in Washington. Though clad in the same marble as its predecessor, Pei’s building always appeared to be made of white cardboard, like a flimsy architectural model.

Well, recent developments have proved that the Pei building was not constructed with the same care and durability as earlier museums from the Beaux Arts era in Washington. After only 35 years the marble panels on the exterior have begun to fail, endangering pedestrians and worrying the museum staff. When initially designed, Pei defended his triangular masses by trumpeting their pure abstraction. Abstraction was a watchword of modernism in all the arts, but in architecture it proved very difficult to achieve. The desire for taut surfaces and invisible joints drove designers to employ clever details that allowed buildings to look like monolithic sculptures of glass, metal or stone while also floating effortlessly in space. Details that allowed buildings to be built with thin veneers of stone, like those of the East Wing, were devised de novo by engineers and architects who believed that new technologies would make pure abstraction possible. If an architect built a paper or cardboard model and wanted his building to look like paper or cardboard, presto, a technology would be invented to accommodate his conceit. Pei’s partner, Harry Cobb, tried such a gimmick at the Hancock tower in Boston and spent most of career defending lawsuits after glass panels rained from the sky. Never mind those 37-degree angled joints at the corners–just caulk the hell out of them!

Today, the venerable Mr. Pei will have to answer for a similar act of hubris thirty five years ago. It’s interesting to look at the kind of elegant abstraction of surface and detail that Pope achieved at the National Gallery in the early 1940s, using carved blocks of Tennessee marble laid as a bearing veneer against a steel structure. Pope used the wisdom of classical building design and construction dating back to Roman times, combining it with the latest structural techniques of his own time. Instead of inventing details to serve a design imperative, he learned from past masters and adapted proven details to a new problem.

Engineer Robert Silman and his talented staff will probably figure out a way to re-attach Pei’s marble/cardboard panels, albeit at enormous cost and embarrassment to the gallery administration. He did something similar for Frank Lloyd Wright at Fallingwater and the Guggenheim. At a time when material scarcity and high energy costs are driving the building industry, have we the right to spend resources fixing the mistakes of every architect who put his ego ahead of sound construction practice? Since Pei’s East Wing has won countless awards from fellow architects, there is little choice but to find a solution to this nasty public safety problem. Perhaps next time a major museum constructs a piece of abstract sculpture and calls it architecture, someone will ask for curtain wall tests before issuing a C.O. Oh, and by the way, the Guggenheim board ought to put some pesos away for fixing another architect’s folly. It won’t be long before titanium starts flying around in major cities throughout the globe.