CLT: 3, 5, or 7 layers of dimension lumber, each layer perpendicular to adjacent layers, bonded with structural adhesive. ANSI/APA PRG 320. Species: SPF, Douglas Fir, Southern Pine. Typical panel: 4 ft wide x up to 60 ft long x 3.5-12 in thick. Structural: works as wall, floor, and roof simultaneously. In-plane shear, out-of-plane bending, axial compression. Fire: predictable char rate per NDS, 2-hr ratings achievable with 7-ply panels. IBC 2021: permitted up to 18 stories (Type IV-A with noncombustible protection). Connections: self-tapping screws, angle brackets, hold-downs. Cost: $25-$45/sf for material. Speed: panels CNC-cut in factory, erected 1 floor/week typical. Carbon: sequesters ~1 ton CO2 per cubic meter. CSI 06 17 53.