Steel and concrete manufacturers and their trade groups oppose changes in U.S. building codes that would allow mass timber for tall buildings. Their arguments center on fire safety, strength, and durability, while making the case for the environmental benefits of their products.
The American Institute of Steel Construction contends that the steel industry is a “world leader” in using recycled material and end-of-life recycling, and has made strides to lower greenhouse gas emissions below regulatory requirements. At a webinar on resilience in November, the National Ready-Mix Concrete Association and the MIT Concrete Sustainability Hub presented research which claimed that enhanced concrete design is more cost- and energy-efficient than non-engineered wood design.
Concrete and steel both beat mass timber on price, although that advantage is narrowing. StructureCraft Builders’ Lucas Epp says that by using nail laminated timber, the Building Team got construction costs for T3, in Minneapolis, to within 5% of steel.
Paul Fast, of Fast + Epp, says his team got the cost of Brock Commons, at the University of British Columbia, “very close to the price of using concrete.” He concedes that wood construction “groans on the cost front” for buildings with bigger apartments or wider interior spans. In markets like Washington, D.C., where building with concrete is relatively cheap, “wood has less hope,” he says.
Prices should come down as new innovations emerge. Freres Lumber Co., Lyons, Ore., is refining its new product, mass plywood panels, as a lower-cost alternative to CLT. MPPs require 20–30% less wood because they use engineered veneer and custom plywood layups as base materials. The panels can be fabricated in sizes up to 12x48 feet, and in thicknesses up to two feet.