The Palazzo Proto has a severe neoclassical design: the ground floor is entirely clad in smooth ashlar, incorporating the simple openings of the main door (barely marked by the coat of arms) and the shops; five elegant balconies open onto the main floor and the attic is crowned by acroteria with stylised palmettes. The main façade is faithfully echoed on Via Ryolo. Particularly successful is the arrangement of the small courtyard with an elegant staircase leading to the first floor.