This document describes the extension of an educational tool (LESM – Linear Elements Structure Model), developed on PUC-Rio and implemented in the MATLAB environment for metallic dimensioning of 2D frames, following the precepts of the Brazilian dimensioning standard, NBR8800:2008. The entire development steps are described in details, along with references of the standard used, since the new feature must strictly attend its precepts. The order of the adopted steps is: feature requirements gathering, software requirements gathering, analysis, program project, coding, test and operation. It is worth mentioning that all of the steps are based on the objects oriented language MATLAB, which the software LESM was developed. The previously mentioned phases are elucidated through UMLs schemes for a better understanding of the organizational relationships and processes used. Thus, comparatives of the implemented new data structure with the previously available in LESM documentation, disposed in UML diagrams, can be traced. Furthermore, despite the predominant language used in the development is MATLAB, will be also mentions to JavaScript, used to elaborate some resources of the new feature. Finally, after clarifying all aspects of the development process, practical examples using LESM are modeled to demonstrate the new feature along with the results accuracy.