The umbrella vault of Pazzi Chapel in Florence

The extrados and intrados ribbings on the corners of regular polygons with eight, ten and twelve sides are the nodal point of a planning and structural research; this reached its apex with the introduction of the acute fifth, which reveals a control of the geometrical form of gothic principles, reinterpreted with the knowledge of the recent Roman Age findings. The comparison between the dome of Santa Maria del Fiore and the inner dome of the San Giovanni’s Baptistery shows how they are geographically close and far in time. Thus, they reveal unsuspected formal affinities, which are linked to static principles, suggesting a kind of similar planning knowledge. The goal of this study on the “coverings” by Brunelleschi was also to individuate which are the geometrical and structural elements constituting the buildings; it has been necessary to evaluate the historical references, that are the evolution of existing stylistic elements, and to understand their constructive characters. Brunelleschi’s desire to experiment new spatial solutions in function of the different projects is shown by the knowledge of these elements. This research has always determined the use of new covering structural systems: the chapels which were destroyed in the ‘700, the web vaults of the Loggia in the Ospedale degl’Innocenti, to the so much investigated and enigmatic umbrella in the Pazzi’s Chapel and in the Old Sacristy of San Lorenzo. Finally, the author returns to the cap structures with simple ribbings, to return a visibly similar space, structurally different. The genial Brunelleschi lesson is very difficult to be followed, so his successors have often simplified it so that every worker could manage with it; but it has been fully understood in its complexity and transformed in the “new” language of Michelangiolo.