SDC ranges from A (lowest risk) to F (highest) and can add 8-15% to structural costs.
SDC A: minimal risk. SDC B: 1-3% additional cost. SDC C: 3-6%. SDC D: 8-15% (common along Wasatch Front). SDC E/F: 12-20%+.
Salt Lake City, Provo, Ogden: SDC D. Boise: SDC C-D. Idaho Falls: SDC C.
Structural system selection, foundation design for liquefaction, non-structural bracing, increased engineering fees.