These artists preserved in their sketches details of the Balbus complex that are no longer visible today. Baldassare Peruzzi drew a plan of the complex at the end of the 15th century, when the Crypta was almost intact, occupied by shops, houses, and a church and cemetery. Palladio also drew a plan. Piranesi sketched the support walls under the seats in the cavea.

Antonio Sangallo the Elder made a series of drawings at the beginning of the 16th century, before the final collapse of the theater.

This sketch by Sangallo shows a segment of the porticus of the Crypta directly behind the scene building, with its walkway cut in two by central columns

A plan of half the porticus by Sangallo shows the arrangement of the central columns, which were double the number of the outer pilasters

This elevation design by Sangallo shows the travertine and brick construction of the porticus as well as its second storey