To address such a comprehensive subject in a talk, first the requirements for a certain product property are described. To answer the question of what pit clay or additive is suitable for what product, besides knowledge of the mineralogical characteristics of the raw materials, the influence of the body composition must be determined in tests. For optimization of the thermal conductivity of vertically perforated bricks, the combined use of organic poreformers and inorganic lightweight materials is a key raw materials measure. The demand for higher load-bearing strength of wall elements on the...