The traditional methods and the mechanisms, which were being adapted by builders at that time, were not suitable for the accomplishment of this task. One of such methods consisted of filling of the space, limited by octahedron, wooden scaffolding, which could support rock cupola, until it hardens. But lumber (forest) was expensive and furthermore among the builders there was no unity in the selection of methods. Therefore in 1331 a competition was declared among the architects as it used to be in the Florentine republic. In 1420 the two well-known architects were chosen: Filippo di Ser Brunelleski (1377-1446), Florentine sculptor and the gold matters master, and Lorenzo Ghiberti (1378-1455), also a widely well-known master. Specifically, Lorenzo Ghiberti obtained an order for the production of the bronze doors of the baptistery in front of the building of the cathedral.