Do all shearwalls, parallel to an OMF in the same story, have to be designed with an R factor of 3.5?
No, only the shearwalls along the same wall line as the OMF need to be designed for an R=3.5. Shearwalls parallel to the OMF, but not in the same wall line, may use an R=6.5 if the structure meets all of the following requirements from ASCE7-05 12.2.3.2: • Occupancy category I or II building [see Table 1-1 in ASCE 7-05 or Table 1604.5 in the 2006 IBC] • 2 stories or less in height, and • Light-frame construction or flexible diaphragms are used. OMF Alternate Loading Worksheet.
