The trick is to preserve the naturally occurring pre-tensioned structural fibers that allow trees to grow upwards against axial loads while withstanding lateral ones, say Roald Gundersen, AIA, and Amelia Baxter, who founded WholeTrees in 2007. Their 14-person team sources species such as ash, black locust, oak, and pine from public and private forests in the upper Midwest. It visually grades wood that has uniform dimensions based on ASTM standards for structural poles while the non-uniform pieces are scanned as a 3D mesh and analyzed digitally to identify structural weak spots. In application, systems using the load-bearing trusses, beams, and columns are engineered to accommodate these weak spots. The wood is then peeled, treated to repel insects and fire, and stained and sealed...