A computational tool for the study of proportional balance is introduced as an apparatus for investigating Andrea Palladio's design of Villa Almerico, more familiarly known as Villa Rotonda, in the second book of his Quattro Libri dell'Architettura. The objective of this investigation of Villa Rotonda is to find a novel outcome from the morphological transformations of the villa, where the transformations are generated from parametric variations of the villa while maximizing its proportional balance. The outcome confirms Palladio's mastery of proportional treatments of his design of Villa Rotonda and shows various morphological descendants evolved from the original design. It suggests a new way of employing a parametric geometry in the formal study of a classical building and its stylistic evolution.