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Thought Leadership Sustainable Communities

Georgia’s Mass Timber and the Triple Bottom Line

Southface Institute

By Shane Totten, Southface Institute

UPDATE: Since the time of this article’s original publication, HB 777 passed the Georgia Senate on June 16 and was signed into law by Gov. Brian Kemp on June 29. HB 1015 did not move out of the Senate, but Southface and our partners continue to work together to bring it back to the table next year.

In the weeks before COVID-19 disrupted daily life, the Georgia General Assembly was considering two bills which Southface believes may be able to accelerate the transition to a regenerative economy. House Bill 10151 (HB 1015) could update Georgia’s carbon sequestration registry2 to include building products that sequester carbon. (Did you even know Georgia already has a carbon sequestration registry? Me neither.). House Bill 7773 (HB 777) could instruct the Georgia Department of Community Affairs to investigate amending the state’s building codes to allow “tall” mass timber construction types to serve as an alternative to the typical steel and/or concrete construction commonly used in tall buildings.

You may be aware that existing buildings impose a significant burden on the country’s energy systems. In 2018 buildings represented about 40% of total energy consumption generating about 40% of annual greenhouse gas (GHG) emissions.4 5 You might not be aware that newly constructed buildings contain a substantial amount of embodied carbon because the energy, materials and processes they require to be constructed emit carbon before the building even begins to operate. That embodied carbon comprises about one-fourth of annual building related emissions. Ten percent of all US annual emissions come from constructing buildings!

The Kendeda Building for Innovative Sustainable Design at the Georgia Institute of Technology uses mass timber as a sustainable structural building material.

With Georgia’s population expected to grow substantially by 2050, and urban centers growing worldwide, embodied carbon in new buildings is going to have major consequences for achieving carbon neutrality by 2030 or 2050. It is anticipated that the world’s building stock will double in area by 2060.6 New buildings are certainly more efficient than most existing buildings, but the compounding nature of carbon means it’s critical that we reduce and eventually eliminate their embodied carbon if we are to hit our carbon-reduction goals. Mass timber can play a major role in getting us to carbon-neutral buildings.

What is mass timber?

Generally speaking, mass timber is assembled panels of wood that are six feet or more in at least one dimension. Most mass timber products are laminated assemblies where glue, nails or dowels are used to hold together individual members to form large panels strong enough to serve as structural building material, even high-rise structural building material. Buildings can be constructed almost entirely of wood when mass timber is combined with other engineered wood products, like glued laminated timber (or glulam) beams and columns.7

Design and construction benefits

From a design and construction perspective, there are quite a few advantages to using mass timber. Constructing with mass timber is about 25% faster than constructing the same building with conventional reinforced concrete.8 Because the components are pre-manufactured in controlled conditions, quality is consistent and manufacturing is faster. Fewer construction crews are needed to assemble the components on the job site, and the wood panels can also be used for finished surfaces for floors, walls and ceilings. As an added bonus, the exposed wood grain also reinforces occupants’ connections to nature through biophilic design – a critical element for occupant well-being.

Mass timber carbon-emission benefits vs. steel and concrete

Concrete, the most common construction material on the planet, is an inherently intense carbon emitter. The curing process of concrete’s portland cement releases about one pound of carbon for every pound of cement. Some estimates indicate that portland cement accounts for 5% of total carbon emissions.9 Remember, most concrete construction includes both concrete—made of portland cement, sand and aggregate—and steel reinforcement.

Steel is an even greater carbon emitter than concrete, releasing one ton of carbon per ton of steel. The manufacturing process globally drives some of these emissions, though local North American and recycled steel processes help to lower those emissions. Worldwide, steel contributes over 6% of total greenhouse gas emissions.10

Wood building materials present a very different carbon profile. As trees grow, they inhale carbon dioxide and exhale oxygen. One tree can sequester about 50 pounds of carbon dioxide per year and as much as one ton in 40 years.11 While we still need concrete and steel to construct our buildings, mass timber and engineered wood present an opportunity to use a building material that sequesters carbon rather than emits it.

Forests as areas of carbon sequestration

Forests and human-planted tree farms sequester carbon and hold it, but they also release carbon into the atmosphere, as trees die and decay. Old-growth forests may contain more sequestered carbon than younger forests or farms, but younger trees absorb it at faster rates. Given the density of most tree farms, there is great potential for sequestration.

The need for statewide strategy

Given current population and building stock growth projections, we will need to leverage as many statewide and regional strategies as possible to build efficiently and still achieve carbon neutrality by 2030 or 2050.[12] With Georgia containing over 22 million acres of commercial timberland—more than any other state—we have the potential to be a national leader in carbon sequestration as well as mass timber production and construction.13

Concrete cannot be recycled, but it can be crushed and re-used. Its steel reinforcements can be pulled and recycled. And, steel can be recycled almost infinitely; when it is recycled, it has a much lower carbon footprint than virgin steel. In contrast, trees can be planted on a regular basis, introducing new carbon sequestration sources while remaining a regenerative, reliable source of building material. With forestry as predominant as it is in the state, wood building materials are local building materials.

Job (market) opportunities in mass timber

Until very recently, mass timber was primarily manufactured in the Northwest and Northeast. The time, expense and transportation requirements of obtaining those supplies of mass timber products for the Southeast are currently limiting the region’s ability to move toward carbon neutrality. At the time of publication, there is only one mass timber plant located in the Southeast, in Dothan, Alabama.

The market has the opportunity to open new mass timber manufacturing plants in Georgia that would make mass timber products readily available, drastically reduce transportation-related carbon emissions, eliminate reliance on plants in other states and create local jobs. Increased access to mass timber materials could also catalyze more skilled labor capable of manufacturing and installing such products across the state.

Carbon sequestration registry

Emission trading programs, also known as carbon markets, are incentive-driven programs to reduce greenhouse gas emissions. They can be either mandatory or voluntary depending upon the governmental jurisdiction. Carbon credits, usually a one-ton equivalent independently verified, can be traded, bought and sold within one or more given markets.14 Endeavors where emissions will exceed allowable levels can buy credits to offset their excess emissions, and endeavors where emissions are below allowable levels can sell their credits. Those credits can also come from investment in other sources, such as forests and carbon sequestering products.

Georgia HB 1015 would expand the state’s existing carbon sequestration registry to include building products and materials that can demonstrate carbon sequestration. This provides an opportunity for the businesses and landowners of the state to begin amassing carbon credits that may eventually be traded in carbon markets.

This potential expansion of the registry through HB 1015 would be an opportunity for Georgia to create new financial resources for the state from existing resources like forestry and construction. If passed by the Georgia General Assembly, there will still be many details to resolve, such as how carbon credits are consistently calculated and how they would be recognized by carbon markets. Carbon sequestering products, like mass timber, will require third-party validated evaluation processes that confirm sequestration calculations and account for previously claimed carbon credits from the material’s supply chain.

These are issues that can be resolved with thoughtful collaboration, and the potential of an expanded registry can help push Georgia’s economy toward a regenerative one in which carbon savings are rewarded. By combining the carbon sequestration registry with other key efforts to advance a regenerative economy, it will be possible to achieve timely carbon neutrality in Georgia and throughout the Southeast.

While Georgia leads the nation in generating many forestry-derived products, like pulp, paper and wood pellets, the pace of growth in the state should be able to sustain an increased demand for mass timber products. Further, the Georgia Forestry Association reported forest growth exceeds removals by 48 %.[14]

Some environmental groups are concerned an increased demand for wood products could lead to forestry management practices that undermine the health and carbon sequestration potential of the natural environment.[15] Southface believes the updates to the sequestration registry proposed in HB 1015 present a compelling opportunity to collaborate with Georgia foresters and other interested stakeholders in optimizing practices for both the carbon sequestration and economic benefit potential of mass timber to be fully realized. Demonstrating that the state is pursuing internationally recognized best practices will reinforce the integrity of current and future Georgia carbon credits in the world’s markets.

Georgias mass timber opportunity

The success of sustainability efforts is often assessed through three factors: people, planet and profit. Efforts that may be good for one factor may not be good for the other two and subsequently fall short of being a truly sustainable solution. Southface believes the intent of House Bills 777 and 1015 can create jobs and increase skills; reduce the carbon footprint of new buildings; and create new economic value from our forests and our buildings. If we truly aim to move to a regenerative economy and implement a timely reversal of climate change, we must continue to adopt such innovative and holistic opportunities.

Featured Image: Forests full of trees, like at Blood Mountain in Georgia, are potent sources of carbon sequestration, with one tree drawing down 50 pounds of carbon dioxide in one year and up to 1 ton over 40 years.

Sources

1 http://www.legis.ga.gov/legislation/en-US/Display/20192020/HB/1015

2 https://www.gsccca.org/learn/projects-programs/carbon-registry

3 http://www.legis.ga.gov/Legislation/en-US/InjectSession.aspx?BillType=HB&BillNum=777

4 https://www.eia.gov/tools/faqs/faq.php?id=86&t=1

5 https://architecture2030.org/buildings_problem_why/

6 Ibid.

7 https://www.awc.org/pdf/education/des/ReThinkMag-DES610A-MassTimberinNorthAmerica-161031.pdf

8 https://www.awc.org/pdf/education/des/ReThinkMag-DES610A-MassTimberinNorthAmerica-161031.pdf

9 https://www.buildinggreen.com/feature/urgency-embodied-carbon-and-what-you-can-do-about-it

10 Ibid.

11 https://www.unm.edu/~jbrink/365/Documents/Calculating_tree_carbon.pdf

12 https://architecture2030.org/

13 https://gfagrow.org/about/numberone/

14 https://nativeenergy.com/2018/02/how-does-carbon-trading-work/

15 https://gfagrow.org/about/numberone/

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