Old brick buildings have undergone constant transformations throughout their existence. Various reasons contributed to this. The aging processes of buildings and their destruction forced users to undertake renovation and construction works. Changes in economic conditions, political, the intensification of cultural life became a stimulus to introduce new trends in architecture and. construction technology. New usage requirements, technical needs or aesthetic preferences, current assumptions and urban planning concepts resulted in redevelopments, superstructure, extensions, connecting tenement houses in the development of street sequences, or reworking old ones, and sometimes ruined buildings. These processes took place with varying intensity and are still taking place today.
With repairs, reconstructions or adaptations of old buildings, during the works, the original structures were often replaced with others, corresponding to the spirit of the times and the prevailing style. In this case, logical design considerations were always followed, both in relation to the materials used and construction technologies.
If aesthetic considerations dictated various changes, then, during the reconstruction, the old walls and structures were covered to achieve new stylistic effects. For these reasons, original materials and coatings were sometimes removed and replaced with more decorative ones. There have also been cases, that at the time of reconstruction or addition, for style unity, new structures were introduced, but based on the older ones, making them look deceptively real.
The reconstructed structures and parts of the buildings were not always of the proper technical quality. Often, incorrect compositional decisions favored genetic and structural changes in the construction organism. These are the reasons that force us to specify the nature of the transformations and the quality of the technical condition already at the stage of the initial recognition of the monument.. At the same time, it is important to recognize and separate the authentic structural systems from these, which were introduced later or which have undergone such far different transformations, that they do not represent a specific value in terms of historical value. The unambiguous determination of the type of historic substance is important not only in terms of research into the construction technique and general characteristics of the building, but it is a starting factor in specifying the static and strength values of a given structural system.
Therefore, it becomes necessary to introduce terminology, that will make this task easier, although from a theoretical point of view it won't matter much.