HEARTWOOD LIFE CYCLE ANALYSIS

In 2024, the University of Washington will release a full Life Cycle Analysis of Heartwood, tracking the Global Warming Potential (GWP) of the building’s superstructure from cradle-to-grave and comparing the results to those of an equivalent 8-story concrete building.

Initial results show that Heartwood’s GWP was 38% lower compared to the concrete equivalent. When offsetting the CO₂ sequestered in the timber, the net result is a 108% reduction at construction and 103% at End-of-Life (EOL) - a carbon negative superstructure.

When its life is at an end, Heartwood’s materials can be reused in other projects. The EOL study projects that 80% of the Mass Timber in Heartwood will be reused in other, new mass timber buildings after Heartwood’s initial 100-year lifespan. Remaining unusable portions of the superstructure will be reconstituted as OSB or Particle Board, which can, themselves, be recycled two times. These processes involve only a small amount of C0₂ loss at each stage, meaning that most of the carbon sequestered in the wood will remain so for centuries. Even when the materials finally reach landfills, it is assumed that 88% of their carbon will remain sequestered after off-gassing.