This Timber Office Building is the First of Its Kind in the U.S.
A new, four-story commercial development in Des Moines, Iowa is the first office building in the nation to be constructed using dowel-laminated timber—eliminating the need for nails and fasteners. Dubbed 111 East Grand, the innovative, eco-friendly building was designed by local firm Neumann Monson Architects.
“The building is unique in that it takes a prototypical, speculative Type-A office building in the heart of the Midwest, which draws its inspiration from the first timber-framed structures that were common centuries ago, and helps transforms that typology by utilizing advanced and highly sustainable dowel-laminated timber manufacturing technology," says Cheung Chan, lead architect on the project.
Chan said the Des Moines building is the first multi-story project in the U.S. to use dowel-laminated timber (DLT); The inaugral DLT project in the U.S. was built for the Museum of Fine Arts in Houston.
The unique, all-wood product is made by StructureCraft, a Canadian structural engineering firm. The timber is sourced from sustainable forests in North America, and is made using a variety of wood species, including Douglas fir, hemlock, Sitka spruce, western red cedar, and yellow cedar. Ryan Companies installed the friction-fit, prefabricated, 8-foot-by-20-foot DowelLam panels, which serve as floors and roof. The 60,000-square-foot building structure also includes a spruce glulam beam-and-column frame.
“We chose to build a mass timber building to offer the market something different," says Tim Rypma, president of Rypma Properties, a Des Moines real estate development firm that served as a partner on the project team. “We didn't want another traditional office building."
Innovative wood product. The project used DowelLam timber manufactured by StructureCraft for the floor and roof assemblies.
All wood. The solid DLT wood panels use hardwood dowels to friction-fit pre-milled boards together on edge, which creates a panel that is optimized for horizontal spans. The result is architectural flexibility; DowelLam can be used for floors, walls, and roof structures.
No nails needed. DLT does not contain any glue, VOCs, or metal nails. As a result, there is no off-gassing, which helps to improve interior air quality.
Environmentally friendly. The use of mass timber provides a sustainable design solution. The advantages of using DowelLam material and systems include the ability for prefabrication, faster production speed, quality-control, durability, and strength. In a mass timber project, the primary load-bearing structure is composed of wood.
Alternative Materials. DowelLam is the first all-wood mass timber panel produced in North America—providing architects, engineers, and developers greater versatility in designing with mass timber. DLT is less expensive to fabricate than other glued products, such as cross-laminated timber. Pre-manufacturing helps reduce time and labor for installation onsite.
Look—no wire fasteners! The DLT columns and beams use glue-laminated timber, which features fire and chemical resistance. DLT panels do not use wire fasteners, and can be efficiently processed using CNC machinery. This results in production of a high tolerance panel that can contain pre-integrated acoustic materials, electrical conduits, and other service interfaces.
Form and function. One of the unique characteristics of DLT is that a wide variety of profiles can be integrated inexpensively into the bottom surface of the panel. Each finger-jointed board goes through a molder that enables customization to suit the performance and aesthetic requirements of a specific project. For example, an acoustic profile can add non-combustible, fibrous insulation to absorb sound while keeping the wood exposed.
Healthy By Design. Using DLT improves interior aesthetics with exposed wood, natural lighting, and ventilation. Khalid Khan, a partner at Neumann Monson Architects, says this form of biophilic design focuses on creating a productive and healthy environment for its occupants. "It speaks to the shared vision of the project development construction and design team—to arrive at a building that is timeless in its appearance and advanced in its execution and utilization of sustainable technology."
Curb appeal. The innovative, mixed-use building—located in the heart of the East Village in Iowa's capital city—has retail and restaurant space on the ground floor and office space on the top levels. It is located in a popular area of shops, restaurants and night life. The building is adjacent to a six-story parking garage, and provides easy access to downtown Des Moines.
