For the construction of bioclimatic cellars, it is required that the materials used on the building have special characteristics that must be evaluated based on the following physical parameters:
1) Thermal conductivity, or its ability to transmit heat from wall to wall. It is defined as the heat flow that crosses a surface of 1 m2 of homogeneous materials when there is a difference of 1 °C between the two surfaces that are 1 m apart. The inverse of conductivity is the thermal resistance, which increases with the thickness of the materials to be covered.
2) Thermal inertia, or the ability of a material to retain heat. The material is designed to prevent temperature changes by delaying the other side of the wall.
3) Thermal resistance which is a function of how much the material is perishable by climatic effects (otherwise the structure would be deformed).
4) Resistance to humidity which affects the degradation of materials and above all, it causes the presence of molds that will cause wines to run along with risks associated with the acquisition of mold or earthy tastes.
5) Fire resistance. A good insulator must not only avoid feeding the flame, but also to resist its propagation, otherwise the development of toxic gaseous emissions.
6) Mechanical resistance, so resistance to crushing. There are considerable differences on insulating materials: cellular concrete are used for building walls.