I have seen thermal gradient diagrams through walls that are usefull for dew point calculations....I think in one of Lstiburek's publications, but you can do it yourself and be close.  If you look you will see how they deal with the different R values of different materials. 

You should really do it with a complete wall assembly, but to keep it simple, assume the concrete core section has an R value of 0 and your inner and outer insulation thickness are the same.  Accordingly, the concrete core temperature will be very close to midway between the indoor and outdoor temperature.  Despite the relatively low permeance of EPS, because of the joints in the ICF, the concrete could be considered a condensation plane even though the joints affect a miniscule area of the wall.

If you know the indoor design conditions (temp and humidity), the dew point can be compared to the core temperature of the wall.

Your architect should remember that (in order):

1. Water vapor is moved by air movement
2. Water vapor is driven from warm areas to cold areas by thermal gradient
3. Water vapor is driven from high concentration to low concentration by the concentration gradient

I don't think any of these will be a problem with most  ICF situations unless you want to build a heated, indoor swimming pool room in the north country.

Bruce