I have a project ( 6000 sq. ft house) permitted a few months ago under the
94 UBC. Before contractor started construction decorator made some changes
to the window location in one wall. (Instead of two longer wall now I have
three shorter walls of about 6' each.) I checked with building official
and was told to design that wall line only to comply with the 97 code.
Since I had a pair of cantilevered columns in line with this shear wall I
used an R=2.2. Based on the soil report I ended up with a base shear of
about .56W/1.4=.45W. That's compared to the original factor of 0.183W.
Building official also wants me to also design for the Redundancy factor. How
can Rho be determined under these circumstances. Any ideas or suggestions