As the nation pushes forward toward net-zero and sustainability goals, the built environment has a significant role to play. Material choice can have a tremendous positive impact, with advanced engineered wood products driving us closer to net-zero carbon.
In the second consecutive year of the Softwood Lumber Board (SLB) and USDA Forest Service’s Mass Timber Competition: Building to Net-Zero Carbon, five innovative projects stood out from the rest, receiving funds totaling $2.2 million to demonstrate mass timber’s applications in architectural design and to highlight its role in reducing the built environment’s carbon footprint.
This year’s competition was executed and funded by the SLB and USDA Forest Service with the goal of showcasing the expanded use of mass timber in the United States and inspiring broader adoption in commercial applications across the country. The entries highlighted mass timber’s impact on building practices that will help designers and developers meet sustainability goals with their projects.
To further the impact of the program, award recipients have pledged to share lessons learned during project phases—including cost analyses, life cycle assessments, and other research results—with the broader design and construction community to encourage more widespread adoption of mass timber as a structural material in similar projects across the country.
Winning proposals were selected by a jury of AEC thought leaders not just for their design excellence, but for their commitment to exploring new ways to design and construct mass timber buildings in the U.S. at a higher scale through replicable, cost-effective construction methods, as well as a commitment to strengthen the mass timber supply chain by using domestically sourced wood from sustainably managed forests.
The 95,000-square-foot, five-story mixed-use residential project is inspired by a former carriage house shell that was located on the property in the historic Brush Park neighborhood. The project is built around a new carriage house enclosure that honors the legacy of the original with a nod to its scale and form. A mass timber structure complements the carriage house and signifies the project team’s commitment to a greener future. The two-story bar and lounge that occupies the carriage house connects to a new one-story restaurant. Above the restaurant, the building will have a 5,000-square-foot commercial office space alongside luxury residential flats and lofts, each with a unique footprint and outdoor terrace. The use of mass timber in this development gives a nod to the use of wood and timber in the neighborhood’s historic buildings while also representing modern mass timber construction’s sustainable values. The project’s mass timber structural system includes glulam beams and columns and CLT floors.
“Mass timber has many attributes that make it a practical solution from a cost and design perspective. Its inherent beauty and fire resistance (char protection) allow it to be exposed as a finished material, eliminating the cost and labor associated with additional finish materials and coatings. The prefabrication of glulam beams, columns, and CLT slabs saves time and labor on site. These cost savings, in tandem with sustainability and environmental goals, make mass timber a great option for residential mid-rise construction. … The team believes that the softness and warmth of the wood structure has played a large role in condo pre-sales, an instrumental factor in the success of this development.” – Project Submission
This overbuild in Keene, New Hampshire, will add three stories and 57 apartments on top of a steel building, providing a further example of how mass timber can be used to vertically expand existing structures, adding density. Up@310 Lofts is located near downtown Keene’s Business Growth and Reuse district, which encourages new development and redevelopment while preserving the character of the residential neighborhoods and improving the area’s vibrancy. A lack of housing in the district has created an urgency to build long-term, sustainable, and resilient housing in Keene. The team envisions this net-zero energy project as a catalyst for future sustainable development in the city. An addition to an existing two-story mixed-use commercial building, this overbuild includes mass timber glulam posts and beams with CLT floor slabs. Mass timber was selected for its lighter weight (and therefore reduced additional load on the existing foundations compared with other structural systems), faster dry-in time, and the opportunity to use advanced framing strategies for improved energy performance, as well as the ability to sequester carbon and add a warm wood aesthetic to the apartments.
“The case for mass timber construction includes a lighter-weight assembly on top of the existing building and foundations, net-zero energy, and high-performance wood wall panels that use advanced framing strategies and cellulose insulation. In addition to sequestering carbon, the mass timber structure will add to the interior aesthetics of the 57 new apartments with beautiful warm wood ceilings.” – Project Submission
Via is a pilot housing project for the Northwest Arkansas Industrialized Construction program, an initiative of Blue Crane developments that is intended to help address the need for new rental housing in the region due to its rapid growth. The project consists of four market-rate and affordable multifamily residential buildings totaling 131 units. Two of the buildings in the complex, Emma and Water, will be built using conventional wood framing. The remaining two buildings, Meadow and Park, will be built with a standardized, industrialized kit of parts consisting of CLT panels and prefabricated bathroom modules, exploring further possibilities for mass timber offsite construction. The project team selected mass timber not only for its construction speed and aesthetic beauty, but also because of a commitment to sustainable, affordable housing development.
“One of the most compelling benefits of this kit of parts approach to construction is the speed it confers to the building process. That speed translates to lower general conditions cost for the contractor, a lower headcount on site, and a reduction in interest carry cost for the developer. … The system being developed for this project takes advantage of the strategic structural use of mass timber on certain building typologies in order to maximize construction speed and architectural appearance while maintaining affordability.” – Project Submission
The Village SF Wellness Center is a six-story, 45,000-square-foot mixed-use commercial and multifamily project developed by Friendship House and a coalition of Native-led nonprofits in San Francisco. The goal of the project is to reclaim physical and cultural space for urban American Indians by creating a first-of-its-kind intertribal “gathering of fires”—a physical, cultural, and spiritual nexus providing essential services and facilitating community connection by and for urban American Indians. In addition to providing office space for Indigenous-led organizations and programs, The Village SF Wellness Center will house a cultural and elders hall, a youth center, dental and medical clinics run by the Native American Health Center, two floors of interim supportive housing, and a rooftop garden and farm where food for the programs will be grown. The Type IV-C mass timber structure will be left exposed on the interior to reinforce the owners’ commitment to natural surfaces. The structural system includes a post-and-beam glulam system with CLT panels.
“The core drivers of the project are connecting with the natural environment, introducing Indigenous values to an urban setting, and providing a warm, healthy, and healing indoor environment for residents, occupants, and visitors. No other structural system can provide these benefits, while mass timber can embed the project’s values into the building’s very core. … In addition, the highly regular prefabricated mass timber system will expedite the construction process, reducing the required staging space, reducing the overall construction time, and reducing impacts on the surrounding neighborhood—these are critical advantages on any compact infill site.” – Project Submission
Woolsey Gardens is an eight-story, 59,570-square-foot high-rise multifamily project with commercial space on the first floor and a permanently affordable housing community above. The project team aims to use Woolsey Gardens to accelerate the production of sustainable and financeable permanently affordable housing units for sale to low- to moderate-income households as an alternative to affordable rental housing units. The zero net energy building features a solar microgrid, high-efficiency mechanical systems, a comprehensive demand reduction program, and it is designed to achieve LEED Platinum certification. The project team chose mass timber because it offers a number of tangible benefits to the project, including to sequester a meaningful amount of carbon and meet the project’s bold environmental goals; address overstocked forests in Northern California and the Pacific Northwest; and support an ambitious construction schedule and construction staging limitations. Projected to be the first Type IV-C mass timber building in California, the project’s primary structural system will rely on CLT panels for floor framing and glulam beams and columns.
“Each level of mass timber that is replaced by a typical building material such as concrete or steel reduces the embodied carbon of the building significantly. This is why the project team determined it was critical to maximize the use of mass timber construction, extending the mass timber system from the ground floor to the roof. … [In addition], the team values wood for its aesthetic quality and warmth. Too often, developers use less accessible, cold materials, like steel and concrete, in affordable housing—as an ownership, not rental project, the team wanted to support a sense of pride for homeowners, many of whom will be first-time homebuyers.” – Project Submission