Using cross-laminated timber (CLT) as an alternative to concrete or steel would likely provide modest savings on construction costs while reducing the environmental impact of new construction, according to a feasibility study issued by Mahlum, Walsh Construction, and Coughlin Porter Lundeen. (For more on the environmental benefits of CLT, see Engineering a Wood Revolution.)
Using a recently completed existing building as a benchmark, the report compares concrete, steel, and CLT structural materials based on life-safety issues as well as cost for a hypothetical ten-story multifamily building in Seattle and concludes that a quicker construction time helps contribute to overall cost savings of approximately 4%.
Other factors contributing to savings included the ability to use a less skilled workforce, while the analysts considered the potential need for temporary protection of the structural materials as a mark against CLT’s affordability. “Because there is little local experience with this construction system, CLT construction is estimated at a cost premium until competency and familiarity is established,” the authors note, adding that the 4% savings is conservative because of unknowns. They also suggest that costs will come down even more if the materials sees market uptake in the region.
By Paula Melton