Hi JP,
Welcome to the forum!
No, the beams were not from Michigan. They came from somewhere in Vermont.
We did get the SIPs (Structural Insulated Panels) from Insulspan, which I think is in Blissfield.
The windows were cut out of the SIPs at the factory, and we had the drywall nailed on the SIPs in the shop. Once you erect the frame, the SIPs are nailed on, and you have your walls!
I hope you decide on this type of construction. You will like it!
Radiant floor heat is terrific!
Since the house cannot breath, you need an air circulation system. We have a whole house heat exchange system which replaces the air periodically.
Bill