With the recent passage of the Farm Bill, investment and commercial interest in cross-laminated timber (CLT) and other engineered wood products is poised to take off in 2019. The new bill authorizes the Timber Innovation Act, which was introduced in 2017 and incentivizes investment and R&D into these and other wood products that can support multi-level structures taller than six stories.
The Timber Innovation Act language that was attached to the 2018 Farm Bill includes objectives to:
- Establish a performance driven research and development program for advancing tall wood building construction in the United States.
- Create federal grants to support state, local, university and private sector education, outreach, research, and development, including education and assistance for architects and builders, that will accelerate the use of wood in tall buildings.
- Authorize technical assistance from USDA, in cooperation with state foresters and state extension directors (or equivalent state officials), to implement a program of education and technical assistance for mass timber applications.
- Incentivize the retrofitting of existing facilities located in areas with high unemployment rates, to spur job creation in rural areas.
With recent developments in wood products engineering, it is now possible to expand the use of wood into more construction projects. CLT-based buildings take less time to construct; because mass timber panels are prefabricated, smaller crews can assemble structures more safely and in less time. The speed advantage is amplified because manufacturing can occur simultaneously with site and foundation work, reducing down time between construction phases and shortening construction time.
CLT-based buildings are also more energy efficient. Unlike other building materials, they are comprised completely from renewable materials that sequester carbon, keeping it out of the atmosphere indefinitely. Using wood in place of fossil fuel-intensive materials avoids most of the greenhouse gases that would have been emitted during the manufacturing of such products. While a ton of cement emits nearly a ton of carbon in its production process, a ton of timber has the potential to remove (and store) up to two tons of carbon absorbed from the atmosphere.
The American Wood Council notes that “The rise of green building practices means more attention on how our country's buildings impact the environment. The ‘Timber Innovation Act’ would enhance the opportunities for the construction of buildings that will have the lowest environmental impact. Recognizing that wood, among the major construction materials, provides the lowest life-cycle impact, policymakers have increasingly turned their attention to using it more (along with tall wood) to lessen the environmental burdens associated with the building sector.”
Modern building codes are also being updated to include the use of CLT and other innovative engineered wood materials in taller buildings. Fourteen mass timber code change proposals were recently approved, clearing the way for their inclusion in the 2021 International Building Code (IBC). The timber code change proposals create three new types of construction in the United States, setting fire safety requirements and allowable heights, areas, and number of stories for tall mass timber buildings up to 18 stories tall.
The three new building classifications that will be included in the 2021 IBC are:
- Type IV A - timber buildings permitted up to 18 stories and 270 feet tall at a maximum
- Type IV B - timber buildings permitted up to 12 stories and 180 feet tall at a maximum
- Type IV C - timber buildings permitted up to nine stories and 85 feet tall at a maximum
Type IV C structures are allowed to use exposed timber as an interior finish, however Type IV A structures must enclose all exposed surfaces and include a three-hour fire-resistance rating for the structural elements.
Wood-building construction directly supports the forest value chain that supports the rural American economy. Increased demand for wood raw materials means that landowners will be more likely to manage their land for timber growth and cyclical harvests, thereby keeping forest lands forested. These forests will in turn directly help to support regional logging crews, mill facilities, transportation companies, retailers and end-users of wood products.
While the Farm Bill could have done more to address some of the forest management concerns—particularly in light of the news out of the fire-ravaged Western US over the last six months—it is nevertheless a step in the right direction for the expanded use of forest materials and the communities throughout the US that serve the nation’s forest products industry.