More precise information about the original design can be traced back to a design from the early 16th century, in which a certain Antonio Labacco drafted the floorplan and elevation of the building. It is unclear if this design really conveyed Alberti's original ideas. Nevertheless, the most salient aspect of the building is still immediately apparent today - the configuration in the form of a Greek cross. It also shows a vestibule open at the sides and, from an elevated perspective, the overall appearance of the church, which was never fully realised. The draft also displays a large cupola and double tympanum, overlooking a façade similar to the one at Sant'Andrea.