The architecture of the Asciano residence of the Tolomei family is characterized by a travertine façade opened by two very lovely late gothic windows with sharply arched gables. Despite modifications over time, it preserves the typical form of dwellings used for the commercial activities of the owners. It is characterized by a courtyard with a broad entrance way for loading and unloading goods.
The windows are related to the addition, to the original building, of a large salon used as a commercial office and resting on mighty brick arches, built inside a former walled courtyard. In the new courtyard, the warehouses and the servants' rooms were made with an extension of the structure on the north side of the building.
From the style of the two large windows it is assumed that the expansion was carried out in the second half of the fourteenth century, simultaneously with the modification of the path of the Lauretana route, which previously corresponded to the present street Bartolenga.
The enormous size of the bargaining salon, with high ceilings over 4 meters, gives the tangible perception of the great importance the Ptolemies had in local businesses and confirm the commercial flourishing of Asciano in that historic period.