HOUSTON – (By Cynthia Lescalleet for Realty News Report) – Mass timber is going mainstream as more projects incorporate the sustainable building material for both structure and the aesthetics of wood left exposed in the interiors.
As demand increases for more environmentally sensitive building practices, design teams and developers are pushing the possibilities of mass timber use in commercial, institutional and multifamily projects.
Meanwhile, the availability of wooden columns, beams and panels is improving as domestic production kicks in. And building codes are adjusting to accommodate its use in more complex – and taller – buildings, or possibly, future skyscrapers.
Mass timber can be a compelling design choice for reasons both visual and practical, says Steve Durham, Kirksey Architecture’s executive vice president of collegiate projects (and the firm’s self-described mass timber cheerleader).
A timber building has a negative carbon imprint equal to taking 2,000 cars off the road for one year.
While mass timber properties such as carbon reduction, fire resistance, strength and insulation are important, of particular appeal to design teams is its biophilic design opportunity, he says. The concept connects humans and the natural world to affect health and wellness. In other words, the experience of being in a building can be sensory, tactile — and comforting.
Durham compares the move toward mass timber in design and development to what happened with green building practices, now an established industry standard.
Kirksey currently has two large-scale mass timber projects in the Houston area. One is at Rice University’s Hanszen College. A five-story, 57,500 square-foot residential wing is taking shape as engineered wooden panels are locked into place like a giant custom kit from IKEA.
Another is the recently completed classroom building at San Jacinto College Central campus in Pasadena. At 120,000 square feet, it is the largest mass timber instructional building in the country.
They are among the 55 mass timber projects in the state’s pipeline, with 35 commercial, institutional or multi-family projects already started — or completed — as of December 2019, according to a tally kept by WoodWorks, a wood industry education and support resource for design, engineering and construction. Its national figures, kept since 2013, show 1,303 mass timber projects either built or in design stages.
Texas’ first total mass timber project made its debut in 2018: a Gensler-designed 8,500 square foot branch location for First United Bank in Fredericksburg. It was the first project in the country to use mass timber engineered of Southern Yellow Pine, something Texas forestry sources find promising indeed.
That was also the year that a hybrid mass timber and steel building rose in Houston’s Museum District: the Sarah Campbell Blaffer Foundation Center for Conservation at Museum of Fine Arts, Houston, a project designed by the Lake Flato architecture firm with Kendall Heaton Associates.
More recently completed, in San Antonio, is The Soto, a six-story mass timber office building, also designed by Lake Flato, with BOKA Powell. And in Austin, the 89-bed Hotel Magdalena is another Lake Flato project, with the Bunkhouse Group.
Hines, one of the largest development firms in the world, is an early adopter of the engineered building material’s possibilities. The company is using mass timber in its T3 (timber, transit and technology) projects, says Phillip Crocker, Hines senior managing director. A recent example is T3 Eastside in Austin, a project combining 93,000 square feet of office space with 9,200 square feet of residential. The Austin project is the company’s first mass timber project to include residential units, expanding on Hines’ timber portfolio of mid-rise office buildings.
Timber is both renewable and has wellness properties that benefit employees while at work, says John Mooz, Hines senior managing director. He also points to timber’s natural anti-bacterial and anti-microbial properties that outperform other typical construction materials in this respect.
A healthier, more sustainable workplace environment, as with T3, not only promotes productivity but helps companies attract and retain top talent, Mooz says.
When major developers get on board with mass timber projects it helps grow awareness and acceptance of its use, says WoodWorks’ Mark Bartlett, Texas regional manager. It also suggests how they see beyond the costs to the benefits; having a distinct property in a market can attract top tier tenants, higher rents and higher value when it comes time to sell.
LAYERING LUMBER
Traditional timber construction uses single sections of solid wood — and has done so for centuries, harvesting massive trees for use as columns and beams. Think of cathedrals and old warehouses. Today, the term “heavy timber” refers to this building practice.
More of an umbrella term, “mass timber” is a modern class of building materials that bind layers of lumber into larger scale, solid components, WoodWorks’ Bartlett explains. Its fabrication uses sawn timber, not wood chips.
The binding between layers can be glue, dowels or nails, each of which has been in use for a while. The resulting components are suitable for both function (as in load bearing beams, columns, walls and floor or roof decks) and the finished form itself.
The real game changer in U.S. mass timber use, however, has been the advent of cross laminated timber, called CLT, says Aaron Stottlemyer, forest research analyst at Texas A&M Forest Service, a state agency that protects, sustains and stewards natural resource development.
Because it is comprised of three-to-seven layers of cross-grain lumber that’s glued deeply into its cellular structure, CLT panels are strong, durable and rigid in both directions, he says. Notably, they can be fabricated up to 10 feet by 60 feet.
The engineered material weighs less than comparable steel and concrete, helping to reduce their use in foundations and the carbon footprint of producing it. The lighter weight of wood, estimated at one-fifth the weight of concrete or steel, reduces shipping costs, as well.
Factory-produced to specifications unique to each project, a kit of CLT delivered to the job site can be installed more quickly and by fewer workers than traditional steel and concrete, project managers say. That also means the project team needs to meet early and often with the structural, mechanical, electrical and plumbing contractors so that the pre-cut timber sections align correctly to accommodate it all. As a project manager noted, changes on site can be done, but it’s better not to have to.
THE ‘WOOD BASKET’
The International Building Code first incorporated CLT in its wood construction specifications in 2015, with updates in 2018. Code revisions in 2021 allow for its use in buildings up to 18 stories tall. Local jurisdictions, however, vary in their mass timber code updates, industry sources say.
Product availability also has been an issue in mass timber design in the U.S. but that is improving as domestic facilities kick in, Stottlemyer says. As the country’s “wood basket,” the Southeast is in good position to provide the raw material. In a matter of minutes, North America’s vast forests grow enough wood to build an an entire 18-story building.
One of the newer plants, Structurlam in Arkansas, is using Southern Yellow Pine, something the Piney Woods of East Texas has in ample supply, about 13 million acres, he notes.
While mass timber will never entirely replace concrete and steel, he says, with the current emphasis on sustainable construction, “Why would we not be thinking about more use of timber in construction?”
March 15, 2022 Realty News Report Copyright 2022
Photos: Courtesy of Aker Imaging
Feature photo: Rice University’s Hanszen College. A five-story, 57,500 square-foot residential wing. Architecture: Kirksey. Photos: Courtesy of Aker Imaging
File: A Growing Design Trend – Mass Timber
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1 comment
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