It's fundamental that architects know about structures, not only to bring their designs to reality but also to be able to discuss their projects with engineers in order to find the best solutions for construction. Structural pre-dimensioning is crucial to the initial design of the structural components, revealing the restrictions and the possibilities of the spaces.
One of the main loads that a structure must support is its own weight, so it's essential to know this information so that the different parts of the building can be dimensioned. When starting a structural project, the engineer doesn't yet know the dimensions of the different pieces that make up the structure, and therefore, can't know their own weight. A paradox appears without a solution: to know the weight it's necessary to know the dimensions, but, to know the dimensions, it's necessary to know the weight.
During the development of the project the architect finds himself in the curious situation of having to design without necessarily knowing the size of each of the parts of the building (such as the size of the pillars, for example). These important elements directly affect functionality and aesthetics of the project.