Falling down

As it faces demolition, Harvard's Otto Hall provides an object lesson in the perils of museum design

(Paul Warchol) Werner Otto Hall is attached to the rear of Harvard's Fogg Art Museum. The 17-year-old building, which houses the Busch Reisinger Museum, is slated for demolition and removal.

You can think of it as a medical detective story, except that the patient is a building, not a person.

It's a building that broke out with a skin disease that, at first, nobody was able to diagnose.

The building is called Werner Otto Hall. It's a small building, attached to the rear of Harvard University's famous Fogg Art Museum. Otto Hall houses Harvard's Busch Reisinger Museum, a collection of Germanic art mostly of the 20th century.

Indoors, it's a delightful set of galleries. Outside, it's a rotting mess.

Otto Hall opened in 1991. Today, only 17 years later, its exterior walls have deteriorated so badly that Harvard says the only way to repair them would be to take them off and start over.

Yet this disaster was created by the best and the brightest. The client was Harvard, or more specifically the Faculty of Arts and Sciences. The architect was Charles Gwathmey of the firm Gwathmey Siegel, known for - among other buildings - his superb 1992 addition to another museum, the Guggenheim in New York.

The general contractor was Walsh Brothers, a Boston firm now in its fourth generation that has long been regarded as one of the best in the region. Walsh Brothers built the American Academy of Arts and Sciences in Cambridge and much of Massachusetts General Hospital.

Otto was much praised, by this column among others, when Otto Hall opened in 1991. From outside, it was a clean example of modernism, bold but not so bold as to upstage the more celebrated architecture of Le Corbusier's Carpenter Center next door. Inside, it offered a set of galleries that intertwined with one another in unexpected ways.

That's why it's hard to believe that today the whole building - not just the walls, the whole thing - is slated to be completely demolished and removed. Tomorrow the Fogg will close, and eventually new construction will engulf Otto's former site. The new work will be part of a major addition to the Fogg designed by Pritzker Prize-winning Italian architect Renzo Piano, due to open in 2013.

Harvard would like to direct your attention away from Otto's sick walls by claiming that the building just didn't fit in with the plans for the new, larger museum, so it had to go anyway. But Harvard also admits, when pressed, that Otto's exterior was incurable.

So what happened? What's the diagnosis?

To put it simply, the guys who worried about the museum's art were not the guys who worried about the weather. We'll call them the art guys and the weather guys.

The art guys, applying a conventional standard, decided that Otto's interior should be kept at a temperature of 70 degrees, with 50 percent humidity. Those numbers would be best, they believed, for the health of the artworks.

Not only that, but the curators asked that the interior be pressurized, like the fuselage of an airplane. They didn't want cold, dry Cambridge winter air slipping in and damaging the precious artworks. The museum owned world-class works by such artists as Joseph Beuys and Max Beckmann - the self-portrait of Beckmann in a tuxedo is one of Harvard's unforgettable treasures - and also housed frequent touring exhibitions.

If there were going to be any air leaks through the exterior walls, the curators wanted to be sure the air would leak out of the building, not into it.

It's important to understand that this kind of sophisticated climate control was still fairly new at the time Otto was designed. Art curators were making demands that neither the world of architects nor the world of engineers and contractors had quite caught up with.

OK, that's the art guys. The weather guys - the architect, his engineering consultants, and the builder - created pretty much the kind of exterior they'd always built. The primary purpose was not to nurture the art but to keep out the weather. They built what is called a cavity wall. A cavity wall is like a sandwich. There's an outer layer of one material, to keep out the rain, then an empty layer of air, then an inner layer of some other material. Somewhere in the sandwich - the position can vary - there's also a layer of insulation, plus a sheet of something called a vapor barrier.

In the case of Otto, the exterior was finished in porcelain enamel panels, limestone panels, and glass windows. The interior was finished in ordinary drywall.

Now let's focus on the vapor barrier. This is a thin sheet of some kind of pliable fabric, usually plastic. Despite the name, its purpose is not to keep moisture out of the building but exactly the opposite. The vapor barrier is supposed to keep moist indoor air from leaking into the cavity wall.

Why would that be harmful? Because when it's cold outside, as it is in a Cambridge winter, the cavity will be cold, too, and any moist air leaking into it will condense into water, or perhaps even freeze into ice. The effect is like that of water condensing on a cold highball glass on a humid summer afternoon. Eventually, the water begins to damage the insides of the walls, creating rust and rot. At Otto there were times when the walls were soaked through.

Otto, remember, had a pressurized interior. Jim Collins, a Boston architect who is working with Piano on the new museum, puts the situation eloquently. "You've got an engine pumping moist air into the wall," he says. If the vapor barrier were perfect, it would stop the moisture. But in building construction, few things are perfect.

Architect Gwathmey says his wall design was just fine. In a recent interview from his New York office, he suggested other possibilities. "Somebody must have cut holes in the vapor barrier after it was installed," says Gwathmey. "Maybe a subcontractor installing plumbing or telephone connections."

Vapor barriers do, in fact, get punctured. Andy Sebor is a Connecticut engineer who is a recognized national expert in this field. He says failures of this kind are common in art museums of Otto's vintage. He notes that at the Davis Museum at Wellesley, a building by another Pritzker-winning architect, Rafael Moneo, the curators themselves caused problems. They ruptured the vapor barrier by drilling holes to hang artworks.

"You have to keep the vapor barrier away from the owner's drill bit," says Sebor wryly.

Sebor says that both construction methods and curatorial demands were changing in the years leading up to the Otto. "We engineers let architects and museum people go off on their own," he says. "There was a lot of wishful thinking." He notes many oddities, such as the fact that at architect Louis Kahn's gallery at Yale, heating elements were installed in the wall cavity, keeping it dry in winter. Kahn thus solved a problem he may not have known existed. Architects today, says Sebor, are more sophisticated.

There are a couple of other lessons to be learned from Otto. One is that long-term institutions like Harvard should build durably. They're short-sighted when they indulge in the cost-cutting that's common in the commercial world. At Otto, the exterior limestone and metal panels were connected to the framing structure by what are called "ties," small metal connectors. Otto's ties were made of galvanized steel, a material that eventually rusts when subjected to moisture, as it was at Otto. They should have been stainless steel.

Another lesson, perhaps, is that architects should be more wary of new ways of building. In Boston we've seen two other costly cases of architectural skin disease, the failure of windows at the Hancock Tower and of granite panels at 28 State St., the former Bank of New England - both of which were designed by noted architects. And recently the problems of the Stata Center at MIT, by Pritzker winner Frank Gehry, have been in the news.

Otto's problems were never fixed. Nothing worked quite right. The interior never made it up to the desired 50 percent humidity because of the leakage. Even the windows didn't work. They lacked what are called thermal breaks, meaning they, too, could become sources of condensation.

Harvard sued the architect and the contractor in 1996. As usual in such legal matters, neither side will talk for the record, but word on the street is that the parties split the cost of repairs - repairs that proved, in the end, not to make any difference.

Globe architecture critic Robert Campbell can be reached at camglobe@aol.com.