The complexity of teaching structures to architects is described in this article on the basis of the subject: 3-D surface structures and the need to give an insight into the theoretical background. Attention is given to the value of optimised structures and the use of geometrical systems to generate the surfaces. At the same time, the limited value of these means is shown, and the author tries to crawl into the difficult area between architecture and structure. This area is found to be an important, but not very appreciated area of research. Most of the figures shown relate to the Academy where the author works; the rest are from examples used in teaching.