Abstract. The modern brickwork development is related to the material quality improvement and reliability level enhancement for structures. To solve the above problem, this work substantiates moving to the probabilistic standardization of structural behavior of brickwork units taking into account the multi-level hierarchical structure. The complexity of brickwork structure is assessed experimentally on the basis of deformations of structural elements along and across the load direction. The work considers the substantiated reliability level and assurance coefficient, settable during a brickwork test in standard samples. This approach allows the considerable increase of the quality of material, reliability and failure safety of brick structures being constructed.