Even though it will take a couple more years for the International Code Council (ICC) to officially permit the use of mass timber in high-rise buildings, numerous signs point to cross-laminated timber (CLT) and similar products being used increasingly in projects of all sizes.
The ICC changes permit mass timber in buildings up to 18 stories tall. Most current U.S. building codes halt the use of wood above five or six stories. And while many states will wait until the 2021 ICC takes effect to sanction tall wood buildings, others are moving forward now.
In December, the Washington State Building Code Council approved revising its current building code to permit the kinds of wood buildings that the ICC just voted to allow. Meanwhile, developers elsewhere already are making plans that incorporate the ICC’s code changes. One of them is Michael Green, whose firm, Michael Green Architecture, is working on a 12-story mass-timber project in Newark, N.J., that encompasses a half million square feet of office space.
“Lots of regions are giving us an opportunity to build to the future code,” he said.
Green was among the keynote speakers at the Industrialized Wood-Based Construction Conference, which brought together many of the biggest names in mass timber construction. Other keynoters include Andrew Waugh, a London-based architect who has worked with mass timber for more than a decade.
“People in the commercial market are coming to us and asking us to build a timber building, because they know they can rent it for more … because people who work in timber buildings are happier people,” Waugh said. “They work longer, sleep longer, get more done. A biophilic relationship that people have with a building is important, and we’re starting to commercialize it.
“We don’t see this as a choice in construction materials,” said Waugh, co-namesake of Waugh Thistleton Architects. “We see this as a wholesale opportunity for a revolution in construction. Not a viable alternative; the only alternative.”
Mass timber’s advocates cite financial as well as aesthetic reasons to use wood. In the face of pent-up demand for affordable housing and an ongoing labor shortage that has slowed construction’s pace, “we need to figure out how to build more homes with fewer workers,” said Brendan Lowney, a principal and macroeconomist at Forest Economic Advisors, which sponsored the conference.
Marriott International, which opens a new hotel every 14 hours, has embraced a technique in which the rooms in its lower-priced hotels—the kind located near highways that frequently run three to four stories—increasingly are being built in factories in long, rectangular modules. These modules then are trucked to the job site and tied together to create the hotel. Because the site is being prepared at the same time the modules are being built, Marriott has cut its construction time nearly in half, said Dave Walsh, senior director, project management, for Marriott’s Select Brands unit. Modules and mass timber will come together soon with plans for a high-rise hotel in New York, he said.
Many advocates for systemic change also are fans of using wood because they believe it is more environmentally friendly than concrete and steel. Mass timber encompasses a variety of techniques to produce wood in thick blocks that can bear building-sized weights. CLTs, laminated veneer lumber (LVL), and newly invented products like mass plywood panels are examples. Bill Parsons, vice president of operations for WoodWorks, told ProSales in 2018 that he figures there is 200 million square feet of annual construction opportunity for mass timber.
Green also sees recent seismic standards prompting one away from light-wood framing on buildings of up to six stories. “We’re seeing [use of] mass timber start to creep down to lower heights and be economical,” he said.
Mass timber is so relatively new here that it still needs studying, particularly in areas like seismic design, durability factors, and how the building performs once it’s occupied. The TallWood Design Institute, a project of Oregon State University and the University of Oregon, is doing some of that testing. One thing Iain Macdonald, the Institute’s associate director, says he has noticed already is that architects may need to return to the days when they were master builders—people with visionary design skills backed with a knowledge of engineering and details.
This article originally appeare on ProSales.
