At the Digital Building Lab, Georgia Tech researchers develop new ways of using mass timber in commercial construction.

“Mass timber is a process of cutting a tree up into lots of small pieces, essentially observing and removing the defects and then putting those boards back together to make huge pieces of wood,” said Gentry.

“This could be a panel of wood 10 feet by 40 feet by a foot and a half thick,” he said. “That's like a piece of plywood on steroids. That can become a floor system in a 20-story building.”

Mass timber is a relatively new technology: in 2021 Georgia building codes were updated to allow for timber buildings taller than 5 stories using the new mass timber technology. These changes allow for taller and more cost-competitive mass timber buildings.

Very few buildings in the state use mass timber technology. Two local examples are the Kendeda Building, on the Georgia Tech campus, and T3 West Midtown, a 7-story office building in Atlantic Station, near the Georgia Tech Campus.

Although the committee is not the first research group to look at carbon held in buildings, they will still have to develop new models to compare how much wood construction captures carbon as compared to traditional steel, Thomas said.

But, she said, the research is so new that “we can’t just look at what everybody else does and say, ‘that's what we're doing’.”

According to Thomas, the committee is “defining the regulations that will make it possible to have mass timber buildings that sequester carbon in the state of Georgia, and I expect that the procedure we use will be used by others also in the USA and in other countries. So we’re directly applying our expertise to support the state of Georgia.”

One implicit consequence of the amended carbon registry is that it “encourages building these innovative types of buildings in Georgia,” said Thomas.

“I grow my tree. I cut it down. I make a building with it so it's just sitting over there for hopefully a very long time. And then I grow another tree. So I'm taking carbon out of the atmosphere and putting it into buildings on a continuing basis.”

For carbon sequestration to have an impact on the environment, “we're not talking one or two buildings in Atlanta. It has to be really large scale,” said Thomas.

“If we’re going to get the climate stabilized at 1.5 degrees centigrade increase, we’ve got to have some kind of technology for taking carbon out of the atmosphere.”
 

And cultivating a new type of construction is no small endeavor, Gentry said.

“The mass timber problem is one of integration. It’s not like there’s a specific problem with adhesive bond lines or the density of wood. The real problem is the entire ecosystem that it’s going to take to make a mass timber industry in Georgia.”

Mass timber components require development of sophisticated manufacturing techniques.

“There’s tremendous capital expense for the presses that make these materials, and automation and CNC equipment that cuts these things into the kind of interlocking shapes that come to the job site and make these buildings so easy to erect,” Gentry said.

“In the Digital Fabrication Lab (DFL) we have much of that equipment. Our students are learning to run that equipment, and so this semester our students are exploring the design and economic potential of mass timber, looking at not only design of buildings, but also the technical aspects of prefabricating the components and bringing them to the site.”

The fact that Gentry and his students can prototype and deliver these building components right from the DFL amplifies the impact, he said. “I think one of the huge strengths of Georgia Tech is its ability to deliver not just knowledge, but instances of that knowledge applied.”

Gentry speaks from experience: he’s an alumnus of the Institute as well as a decades-long faculty member of the Schools of Architecture and Civil and Environmental Engineering. So, too is another member of the Sustainable Building Material Technical Advisory Committee, Devon Dartnell (EE '84) Director of Market Analysis and Research at the Georgia Forestry Commission, and a Georgia timberland owner. Dartnell manages the work of the committee for the Forestry Commission.

The legislation identifies the specific viewpoints and expertise required to craft the new sustainable building carbon registry. Members include Edie Sonnie Hall, a life cycle analysis consultant from Washington State; Brian Campa, Principal at Cooper Carry; Jacek Siry, Professor of Forest Economics at the University of Georgia; Troy Harris, Managing Director of Timberland at Jamestown; Ted Miltiades, Director of Construction Codes and Industrialized Buildings at Georgia Department of Community Affairs; and Bill Howard,  General Manager of Claude Howard Lumber Company.