Thanks Chris

As if it’s not enough to deal with gravity, wind, rain and seismic stuff....
Your point about understanding the physics involved is well taken. And while taking a shower and noticing that I had forgotten to turn the fan on, it occurred to me that the notion of the living space envelope being less moisture laden is a generality. Learning more about this issue can only be good.

And yes I do have a lot of revelations in the shower

I have ordered "Builder's Guide to Mixed Climates: Details for Design and Construction - Joseph Lstiburek" from Amazon, from the description of the book, this would seem to be more for this climate.
I will also endeavor to determine what manufacturer will be supplying the SIPs before turning the plans loose and see about obtaining a recommended installation plan from them.

J.E.B.