The material story cooked into the new Bell Museum

By Andy Sturdevant

The thermally modified white-pine cladding on the exterior of the University of Minnesota’s new Bell Museum in St. Paul is rough. Rougher even than the surfaces of many of the two-by-fours you’ll find in the lumber aisle of a hardware store, stacked vertically and waiting for you to throw them in a cart. Cooked into a solid, durable surface that repels moisture, the wood will subtly shift in color over time while the surface provides an agreeably tactile finish for future generations of visitors to run their hands over on the way to the museum’s main entrance.

Perkins+Will’s Doug Bergert, Assoc. AIA, one of the designers of the new museum, relates an anecdote about the Bell that seems relevant here: Francis Lee Jaques, the Minnesota painter whose handiwork adorns the Bell’s celebrated nature dioramas, had a dismissive term he used for picture-perfect natural-history backdrops. He called them “large Kodachromes.”

In his own work, Jaques used a hard-bristle stippling brush to give the scenes of bison, wolves, and cranes a rawer quality. “He’d use that to roughen the surface of the backdrop paintings, because he never wanted his dioramas to feel like a photograph,” says Bergert. “He wanted to create a spatial experience, so he’d rough up the texture so it didn’t have the sheen associated with wall paint.” In other words, Jaques went about his work with the belief that a rougher surface would feel like a better expression of the natural world. In the same way, the white pine enveloping large portions of the new Bell resists a tidy, Kodachrome view of the natural environment. It’s all there in the texture.

Indeed, the cladding creates a visceral connection to the Minnesota landscape. White pine, the majestic giant of the state’s Laurentian Mixed Forest biome, is what you find in the forests of the Boundary Waters. Both dense and soft, it was the wood of choice for 19th-century American manufacturers. “In the builders’ art, white pine is king,” wrote the Minneapolis Tribune in 1903, an era in which the boreal forests of northern Minnesota provided enough white-pine lumber “to create a boardwalk nine feet wide encircling the earth at the equator,” according to the Minnesota Historical Society.

For the last 30 years of the 19th century, tens of thousands of lumberjacks and hydro-powered mills sawed the white-pine forests of northern Minnesota into oblivion. In fact, the predecessor organization to today’s Department of Natural Resources was founded in direct response to the obliteration of the pine forests and the catastrophic forest fires that followed as a result. Even as early as the turn of the century, there were warnings that the state’s pine forests were being irreparably depleted (“Nothing is, or will be done, for many years, to replace the forest,” warned one contemporary writer). By 1910, the lumber industry had moved on to the Northwest and South. It would be nearly a century before the timber industry reemerged on a large scale in Minnesota.

Presently, there are roughly six million acres of forest in northern Minnesota. These forests are “managed with primary consideration given to long-term ecosystem integrity and sustaining healthy economies and human communities,” according to the Minnesota Forest Resources Council, the organization created in the 1990s to ensure the sustainable management of the state’s forests. The white pine that provides the cladding for the new Bell Museum comes from a Forestry Stewardship Council–certified stand of timber on the shores of Cass Lake near Bemidji. In recent decades, the timber industry in Minnesota has been focused on wood for pulp. The use of white pine at the Bell is something of a demonstration of how thermally modified wood can be used to create dynamic building exteriors that complement a natural landscape.

The thermal treatment process came to the attention of Perkins+Will by way of Patrick Donahue, wood products program director at the Natural Resources Research Institute at the University of Minnesota Duluth. The design team consulted with Donahue early in the project, and he advanced the idea of thermally modified wood.

“A global trade show junkie” is how Donahue describes himself, and at one such gathering in Germany in the 1990s, he came across the technique, developed by a number of Scandinavian firms. “That piqued my interest,” he says. Within a few years, Donahue was working with Minnesota-based engineers to develop the technology domestically.

Thermally treating wood isn’t new; the idea is familiar to just about anyone who’s ever built a fence to keep the cattle in. “Farmers used to char the fence posts before they put them in the ground,” Donahue points out. “Moving this sort of technique from a folk practice into an industrial process . . . that’s what the Finns are so good at.”

Simply stated, the technique bakes the water out of the wood. “Without water, decay doesn’t get its foothold. You cook the hemicellulose out, the sugars,” says Donahue. “It’s a chemical-free way of increasing durability.”

To hear Doug Bergert discuss the process for designing a new building in dialogue with U faculty and staff is to be reminded of why universities can be such fruitful places for science, art, and design to interact with one another in a way they might not (and usually don’t) in other settings. In early discussions about the new Bell facility, U physics professor Lawrence Rudnick proposed a concept that Bergert and his colleagues returned to throughout the design process: “a continuous loop of experiences . . . situated between the cosmic and the microscopic.” In other words, between one end of the natural-history scale and the other.

It’s a rather abstract idea on its face, but reflect on it the first time you step inside the museum. The building itself makes dioramas of its surroundings: Enormous expanses of glass give visitors framing devices for the agriculturally flavored landscape outside. Glass is a material we’ve come to expect in large quantities in sleek contemporary buildings; it both captures and reflects the big blue sky. That’s the expansive, the cosmic.

The cooked white pine creates contrast; it’s ancient and earthy, with a rough texture that, when touched, heightens the sensation of the elements that shaped it—wood, water, and heat, all interplaying in the thermal modification process. It’s Jaques’ stipple brush on the dioramas at work, mottled and rude and, in all its rawness, defiantly not Kodachrome.