The windows and doors of the ICF house are going to be anywhere from 4-7 feet above grade.   Far away from any termites or bugs.   Someone recently told me that I still need to use treated wood for the frames around windows/doors.   They claim that treated wood prevents rot.   The place is in the high desert in a very dry climate with little moisture or wetness.    I'm not sure if the inspector requires it.   Treated wood costs 3x the price of regular wood.  What are your thoughts on the matter?

PS I wish the search function would work on this forum so that I can check for answers to questions before posting.

Treated wood is not required by the IRC when you are more that 8" above grade. However, my civil engineer cousin said you really need to put a vapor barrier between the wood and concrete. Moisture can accumulate in that region because of the thermal differences of the concrete and wood and you can end up with condensation, which is not good. Also, even in a dry climate you can have situation like a "vapor pump." That is a volume that closed in to the point there is no free air movement through it. Because of the daily heating/cooling cycles the volume heats and cools. In the process it sucks in air at night when it cools. That air carries some vapor. But, the heating up of the volume does not drive the moisture out until you reach close to saturation, or dew point. Then when the air cools the dew point drops and vapor condenses out.

So, use untreated wood but put a barrier between it and the concrete. Now, your next challenge will be to find straight 2xs!

I find the search link in the gray bar just above the printer icon works good.