Numerous autograph drawings by Palladio record the complex design process. They show that right from the beginning Palladio planned for two distinct, residential blocks, one to lie along the street and the other contiguous to the back wall of the courtyard. In I quattro libri dell'architettura (1570) the two blocks are interconnected by a majestic courtyard with enormous Composite columns: this is quite clearly a re-elaboration of the original idea in the interests of publication.