The façade is the magnificent work of Ferdinand Fuga (1741), which covers the thirteenth-century mosaics of the previous façade.

One hundred and fifty years separate the construction of the two palaces flanking the façade. Flaminio Ponzio built the structure on the right, which contains the sacristy complex, in 1605, while the papal quarters on the left was designed by Ferdinando Fuga in 1743 to give an overall uniformity to the site.