Planning to build the "dream house" and unsure which foundation option will prove the best over the long run (comfortable, problem free, energy efficient).  I'm in west central Minnesota.  The basement is a walkout, and I'm planning to do radiant heat in the basement with forced air on the main & upper levels.

My original plan was to use ICF for the foundation, but not many contractors in my area use them.  Most of the local builders recommend using block with 2x4 interior walls & sprayfoam insulation (They say poured/ICF foundations aren't as straight, more difficult to finish, etc...).

I've found 1 local contractor who has failry extensive experience with Thermomass.  We're also looking at SIPS for the remainder of the house.  Extreme Panel has foundation SIPS, but I'm a bit hesitant to use a wood based product for the foundation.

Any insights or opinions would be appreciated.

Thanks!

(They say poured/ICF foundations aren't as straight, more difficult to finish, etc...)