Mass Timber Buildings: A New Approach to Sustainability and Net Zero Goals
Mass timber is quickly becoming a solution as the number of institutions pledging to attain net-zero carbon emissions increases. Whether they are leaning on public-private partnership (P3) or traditional delivery methods, owners and developers are recognizing the benefits of wood as a versatile, sustainable, and structurally efficient feature for their projects. With companies like Google and Microsoft expressing support for this renewable resource, experts believe mass timber could challenge steel and concrete as favored materials for construction.
“Mass timber or cross laminated timber (CLT) offers cost and value considerations that developers and clients are seeing the benefit of. Mass timber supports regional economies, saves time on the speed of construction, and is a renewable resource—with the added benefits of improved daylighting and interior aesthetics, which benefits the health and well-being of the end-user as well,” said Swinerton Director of Preconstruction William Silva.
For example, at Oregon State University, Edward J. Ray Hall, utilization of mass timber avoided 2,441 metric tons of greenhouse gases, with a total carbon benefit of 3,590 metric tons; this is equivalent to removing 759 cars from the road or to the energy required to operate 379 homes for an entire year.
Swinerton’s early commitment to mass timber began in 2016 with the design, permitting, and construction of the then largest mass timber office building in the USA—First Tech Federal Credit Union Oregon Corporate Campus—which was delivered 4 months faster and 4% cheaper than structural steel.
In a short period of time, Swinerton has become known for taking on and successfully delivering some of the most challenging mass timber projects in the country. With the number of mass timber projects expected to double every two years, Swinerton has assembled a knowledge base and resources that is not only unparalleled, but sought out by design teams and owners who can tap into a deep pool of experience.
Swinerton recognizes the challenges of developing a project around a new structural system, and brings its expertise to project teams that are seeking creative solutions to make a mass timber project financially viable. Swinerton’s approach is to direct efforts toward reducing overall cost of construction through smart and informed selections of not just the structural system, but to look at how to leverage complementary benefits in building mechanical, electrical, envelope, and interior systems to help achieve low energy goals.
“We can control costs through early input on building code and efficient designs that allow for complementary benefits between building systems and maximize prefabrication to address labor shortages,” added William.
Because Swinerton is a national leader in numerous construction market sectors, it combines market sector knowledge with mass timber advantages to bring beneficial outcomes for its clients. Swinerton has pioneered mass timber solutions to market sectors, including: Affordable Housing, Aviation, Civic, Community College, Corporate Accounts, Healthcare, Higher Education, Life Science, Office, and more.
5 Examples of Swinerton’s Mass Timber Project Experience
The first building to engage a dramatic reclaimed pumice mine acquired for a future Net Zero campus expansion, the expectations were high for Oregon State University. The project identified three goals: develop a flexible and adaptable prototype for the future, demonstrate the campus’ Net Zero energy goal, and incorporate meaningful use of a mass timber structure. The joint team of Swinerton and SRG developed an integrated strategy that found creative ways to meet these goals. Featuring a glulam post and beam frame and cross-laminated timber (CLT) floors and roof system, the project consists of classroom, laboratory, office, and maker spaces, spread across a three-story, 50,000 GSF mass timber structure. Swinerton participated in the pre-application meeting with the AHJ and was able to identify and then support the architect to implement an Alternative Means & Methods approach to maintain a critical Assembly Use while saving the project 2% through the strategy for the building code approach.
The new two-story, 27,090-square-foot office building serves as Harder Mechanical’s new headquarters. It utilizes a mass timber frame, glulam columns, and cross-laminated timber (CLT) floor panels—all of which was fabricated by Timberlab and installed after being locally manufactured in Oregon. The use of mass timber provides for a much lighter building versus traditional structural steel. As a result, the glulam beams and columns utilize shallow concrete footings. Swinerton assisted the design team in reconsidering mass timber (CLT) for the frame to deliver cost and schedule savings.
The Heartwood project will bring workforce housing to central Seattle, filling a critical need for middle-income housing in the city. The project will make use of an innovative, eco-friendly building material: cross-laminated timber (CLT), which lowers the overall carbon footprint of the structure. When completed, Heartwood is anticipated to be one of Washington’s tallest CLT buildings and was the first tall wood building to be permitted in Seattle. This project received a $250 000 Wood Innovation Grant from the U.S. Forest Service to validate the feasibility of Type IV-C multifamily housing. Swinerton supported the U.S. Forest Service grant application and joined the project team in a design-build capacity for the overall construction including the mass timber structure.
Through the design phase, Swinerton worked with the architect and structural engineer to determine the optimal unit layout and structural grid to meet the programmatic and budget needs of the project. Swinerton has also led meetings with the Seattle Department of Construction & Inspections to highlight grey areas of the code for this new construction typology and to propose solutions that address fire and life safety during both construction and occupancy.
Located in the Little Italy neighborhood of Downtown San Diego, this 260,000-square-foot core and shell office building consists of six stories with two levels of below grade parking. The exterior skin consists of precast brick panels, aluminum panels, stucco, structural Douglas fir timbers and aluminum soffits. The rooftop amenity spaces consists of a six-ply cross-laminated timber (CLT) structure surrounded by an outdoor space utilizing a pedestal paver system. Additional amenities include power actuated hardware at all doors and glass entrances, HEPA filtration systems throughout and touchless destination dispatch elevator controls. Swinerton self-performed structural concrete, metal stud & drywall, doors/frames and hardware, CLT mass timber, as well as cleanup services.
Additional Reading: Contractors are Partners for Achieving Sustainable Development Goals