We generally use a six inch wall, which means we are going to have R20 in the wall, which is almost twice what the standard insulation is. These studs are imbedded in the slab and around the outside of the slab. We put a R10 weather resistant foam board right down to the footer. So now we have protected the area of earth underneath the slab from temperature variation. That acts like a flywheel. It acts like an equalizer. What the walls end up doing, because steel is a good conductor, is conducting the temperature from inside. If you look at the earth underneath the building, I would say its like a baked potato underneath your building. It changes temperature very slowly and so that baked potato is going to reach the average temperature. The average temperature over the year for this baked potato underneath the house is going to be between 62 and 65 degrees. So now you are conducting 65 degrees up into your dwelling.
