ABSTRACT
This study proposes a modification of an earlier and exact semi-graphical procedure for analyzing certain structures in building considering the First Order Theory without resolving equation systems. The new, graphical procedure seeks to carry out the same operations graphically by tracing dotted lines on regular surfaces formed by squares with unit-length sides. When drafting instruments are used the results obtained are exact. But when the method is applied without them the results are still highly accurate, since the perimeter of the surface on which the lines are drawn reduces the possibility of error. This freehand method is applied to certain spatial porticoes that may be hard to calculate manually and the results are compared with the exact ones. The study suggests that other methods could be drawn up that would enable different types of building structures to be analyzed almost exactly in just a few operations.
