I read your points on crawl space insulation with interest. I am building a year round home on a lake in Maine (very cold winters). Seasonal flooding requires an open foundation which proveds an open crawlspace (2-5 ft high). I am installing in floor heat. What is the optimal layering of insulation in the joists facing the crawl space? Specifically, does it make sense to provide a reflective layer immediately below the floor boards followed by styrofoam?