General criteria for the project to adopt a constructive solution for the designer must ensure thermal insulation of the first forged by the hearth or the ground if the headspace is a heated local. It is common to use insulation in the floors or sill in contact with the ground when the intended use is the local garage or unheated, is not true for livable spaces or moderately heated. In this case it is necessary to introduce the thermal insulation. This way a large surface heat loss outward whose compensation requires additional inputs of energy.