The University of Arkansas’s Adohi Hall draws from the richness of the tree-covered hills surrounding it. Named for the Cherokee word that means “coming into the forest” and built nearly entirely of mass timber, the $79 million, 202,000-square-foot student residence, in Fayetteville, takes inspiration from the work of two renowned architects from the region. First is the sublime detailing of E. Fay Jones’s Thorncrown Chapel, in nearby Eureka Springs; second is the region’s vernacular architecture as interpreted by Marlon Blackwell, FAIA, a renowned practitioner as well as a distinguished professor in the university’s architecture school, which bears Jones’s name.
Designed by Boston-based Leers Weinzapfel Associates, St. Louis–based Mackey Mitchell Architects, and local firm Modus Studio, Adohi Hall is the largest mass timber building in the country to date—a full-scale demonstration of the potential of wood architecture in a state more than half covered by forests, which supply a $1.7 billion wood products industry. The 708-bed residence hall, which includes 40,700 square feet of classroom, performance, and workshop space, comprises five interconnected timber volumes arranged in a jagged S-shape to create a series of landscaped courtyards designed by Philadelphia-based landscape architecture studio Olin.
Structurally, the building uses exposed glued-laminated posts and beams in concert with cross-laminated timber slabs for floors and roofs. Aside from a second-story garden supported by diamond-shaped wood-and-steel trusses—inspired by those used in Jones’ chapel—the specification of mass timber formed the basis for nearly every design decision, from the residential modules, which were based on standard CLT panel sizes, to the building’s lightweight metal skin.
Originally, the architects envisioned a dark-gray brick exterior, but the realities of mass timber forced them to reconsider. The dead load of the brick would have required steel reinforcement, explains Ashley Rao, AIA, LWA senior associate and project manager for Adohi Hall. “That was putting additional load on the mass timber and driving up the member sizes.” Instead, she says, the design asked, “What is the lightest, most beautiful thing we can hang off of this mass timber building? How do those two materials speak back and forth to each other?”
After exploring several options, the architects settled on a metal rainscreen system with a Kynar resin–based finish from Kingspan. The material selection is in part a nod to Blackwell, who clad his St. Nicholas Eastern Orthodox Church, in Springdale, Ark., in metal siding. “It has this fun profile and [because the building] faces so many different ways, the corrugation really catches the light in different ways,” Rao says.
To add further visual interest and break up what LWA principal Tom Chung, FAIA, calls the “insistent grid” of the building’s fenestration, the design team selected two accent panel colors. Copper panels echo the reddish hues of the building’s Arkansas cypress finishes while the white panels are staggered to disguise the regularity of the windows’ layout. Though the windows do align vertically, Chung says, “at first glance, it looks like the windows are sort of scattered. It’s this visual trick. It’s fooling your eyes.”
The dark gray rainscreen is supported floor-to-floor by metal stud furring, which is filled with fiberglass batt insulation and covered on the outside with gypsum sheathing, a liquid vapor-permeable air barrier to address the region’s varying humidity levels, and 2 inches of Roxul (now known as Rockwool) semi-rigid insulation, for a combined R-value exceeding R-27. Inside, the perimeter walls are finished in painted gypsum wall board.
All told, Adohi Hall should use 42% less energy than a comparable building. Because the building’s first year of occupancy was cut short by COVID-19, however, the project has not, as of yet, produced enough representative data to confirm energy use. The mass-timber structure is estimated to store the equivalent of 3,197 metric tons of carbon dioxide, with another 1,237 metric tons avoided through savings in material fabrication and transport. Altogether, the reduction is equivalent to taking 948 cars off the road for a year.
Additionally, Adohi Hall will offer insights into the hygroscopic abilities and structural performance of mass timber products. The university’s architecture and engineering faculty have embedded sensors into the hall’s CLT floors to measure moisture content and to better understand how the material performs in humid climates over time. (If the moisture content of a CLT panel gets too high, it could jeopardize its structural integrity.)
What is measurable is the regional impact of the university’s continued investment in innovative wood architecture. Shortly after Adohi Hall opened, Walmart announced that its new corporate headquarters in Bentonville would be built with mass timber. As a result, Structurlam, a CLT manufacturer based in British Columbia, will open its first American CLT plant in nearby Conway, to supply the Walmart project with approximately 1 million square feet of locally harvested and manufactured timber.
Structurlam’s presence in northwest Arkansas, Chung says, will speed the adoption of mass timber in the state and across the South, potentially with cascading benefits for its forests and natural areas. “Using the forest and harvesting trees in a sustainable manner actually keeps forests healthier than if you let the trees decay and die,” he says. “But the largest [benefit] is that it’s better for the carbon footprint.” Architects should build with renewable materials wherever they can, he adds—“otherwise we’re not going to have a planet to leave to our next generation.”
