Seriously. I am wanting to build a garage/barn with R-30 exterior walls to maintain a 65F interior temperature year round. I have chinchillas and let's just say this is a MUST not a WANT.

I'm looking into VIP, but for a 24'x30' garage, this just doesn't seem ** feasible. Any other ideas out there?

Most rigid foam panels have a R value of about 5 per inch, so 6 inches of a rigid foam will get you R-30. Of all the foams, I'd prefer isocyanurate...it has a slightly higher R value, and is better in case of fire, although still not good. Any foam will have to be covered with gypsum board in order to conform to codes.