Many contractors prefer this method of insulating a basement slab, although it does isolate the floor panel from the wall it turns the wall into a cold surface, it also leaves you with a soft area around the perimeter of the basement slab that allows infiltration of moisture and gas and makes the installation of floor coverings difficult.
    Many contractors resist change, but if it was not for the demand of the homeowners we would still have four inch walls and single pane windows. It is actually simpler and less expensive than framing out and insulating the inside of the wall.
    We have found that any contractor that has taken the time to put the two inch insulation in the outside of the forms before they pour actually prefers it over other methods.