For the most part, warehouses built in recent decades follow a cookie-cutter formula: a long-span steel structure supporting metal decking with an enclosure of tilt-up concrete panels. But while this model maintains a low cost from a financial perspective, the carbon cost of that formula has become suspect.
In search of a more sustainable alternative, a growing number of business and warehouse developers are embracing a material with a much lower carbon impact: mass timber.
Among the most notable of these projects is Southfield 4, a 161,000-square-foot class A warehouse outside of Dallas. Its developer, Affinius Capital, adopted a hybrid approach to its design: Instead of concrete for its exterior walls, the firm used 50-foot-tall CLT panels clad with insulated metal panels on the exterior. “We were able to achieve a 43% embodied carbon reduction between the timber and the concrete innovation we had on the slabs and site paving,” Affinius Capital Executive Director of Construction Josh Hullum says. The concrete system used a proprietary admixture that reduced the amount of cement needed.
The climate impact of reducing embodied carbon in warehouse construction is significant given the burgeoning growth of this building category. Industrial sector vacancy rates were at 4.1% in Q2 2023, according to Cushman & Wakefield’s Industrial Marketbeat, historically tight compared to the 15-year historical average of 6.6%. In line with the demand for both sustainability and space, the use of wood for warehouses, factories, and industrial structures is now a growth industry. WoodWorks reports that it supported 23 such buildings in 2022, up from 14 in 2021.
Janicki Industries’ new $40 million, 186,280-square-foot manufacturing facility in Hamilton, Washington, is another recent example. The project includes 50-foot-tall ceilings, temperature and humidity control, and a predominantly wood structure and envelope. Using Oregon’s Statewide Alternative Method as a nearby model to guide local code officials, Janicki developed the Type V-B mass timber warehouse and two-story office structure with a combination of CLT, glulam panels, and glulam trusses. WoodWorks provided Janicki designers with support on topics such as area provisions, fire design considerations, and acoustics.
Across the country, L’Oréal’s new $140 million Research & Innovation Center in Clark, New Jersey, comprises additions of 90,000 square feet and 10,000 square feet, and the renovation of 135,000 existing square feet to accommodate new collaboration areas, open office/workstations, a cafeteria, and laboratory spaces. Designers used 82,500 square feet of 5-ply CLT decking in the main roof structure and 7,500 square feet of 3-ply CLT in the clerestory sections. The 5-ply deck can provide the required structural floor support for potential expansion, reducing the carbon impact of that future construction.
And while one-off examples set important precedents, the hope is that mass timber can be adopted in such industrial structures at scale. San Francisco–based Prologis boasts the world’s largest inventory of industrial structures. As one step in their effort to reach net zero emissions by 2040, the firm is constructing a 250,000-square-foot mass timber structure in Brampton, Ontario, near Toronto. The mass timber columns and beams will reduce embodied carbon by 62% versus the steel frame used in their conventional structures. Exterior panels will be made from Nexiite, a proprietary material by Nexii composed of sand, high-quality aggregate and a binder, with no ILFI Red List materials, and result in a 17% reduction versus concrete panels. If the project is successful in helping Prologis achieve its goals, rolling out such strategies over a portfolio of its scale could have much bigger environmental impacts than just a single structure.
The move toward more sustainable development in the warehouse and industrial sector is rooted in evolving good business practices. “You have an investor appetite, especially if you go into Canadian or European funds, where for every dollar that you receive, there’s an expectation of the sustainable transition or approach in some way, shape, or form of doing things better, more responsible investing,” Hullum says.
Warehouses are the next logical space for mass timber development. “We saw a lot of mass timber momentum in office development, [from] 2009 through 2020 or so,” Hullum says. Whereas office development has slowed amidst a sluggish return to work, the boom in e-commerce during the pandemic has only driven demand for logistics spaces higher.
On the horizon, Affinius plans a project similar in scope to Southfield 4 in Northern California. The developer is currently working on a white paper to share with investors and the marketplace that demonstrates how the firm achieved a 43% reduction of embodied carbon at Southfield 4. “Roughly half of that was what we achieved through timber and the biogenic carbon enhancement,” Hullum says. “The other half was through the concrete technology.”
Information sharing like the Southfield 4 white paper could help provide assurance through real-world case studies of mass timber project successes. “It’s not, ‘I have the secret formula to Coca-Cola and I’m going to keep it to myself,’” he says. “If we’re really going to make a difference, there’s an unspoken initiative that we’re going to [have to] be open and collaborative.”
Hullum notes that it’s still early in the development of mass timber within the industrial sector. “If it’s perceived to be of value in the marketplace, especially by tenants and the willingness to pay a slight premium, and we could be more efficient with its implementation and construction, I think there’s a solid percentage base in the class A marketplace for it,” he says.
But Hullum believes there are limits, “It will never be the majority, candidly,” he says. “I do think it’s going to take a lot of appetite and demand from the market to really drive that.”
Hullum notes that value used to be driven solely by financial metrics. “But now, you’re having a demand where value means more than just the financial return,” he says. “That’s an undervalued aspect of timber and what it can provide.”
Beyond carbon, Hullum sees other, more qualitative advantages to the increasing use of timber in warehouses. “A lot of the traction and feedback we receive on Southfield 4 is, ‘This is beautiful,’” Hullum says. “People want to be here; they like this environment.”