The palace was built from 1208 to 1254. At the time of construction, it was an architectural novelty of Italian municipal palaces. Until then, public buildings, mostly above the open market hall of the basement, were just another storey for the council chamber. In proportion to their height, these buildings were also very wide. At this palace, three additional storeys were erected above the originally open hall of the ground floor. The arcades of the hall of the ground floor were pointed at the construction, after the fall of Volterra to Florence in 1361, the arcades were bricked by the Florentines in 1472. The original structure also had encircling wooden galleries, recognizable by the post holes in the outer walls.
The tower of the palace is pentagonal and asymmetrical. In an earthquake in 1846, the tower tower was damaged and then reconstructed, albeit greatly changed.
On the front are the coats of arms of the former Florentine governors, partly made of terracotta, otherwise made of stone. On the right corner of the palace a figure of the Florentine Marzocco is placed on a pillar.
The bifore windows correspond to classical gothic architecture of the 13th century.