The palace, which overlooks Piazza Tola, was rebuilt in 1577 on behalf of Don Jayme Manca on previous late Gothic structures. It represents for Vico Mossa the maximum expression of Sassari civil architecture of the 16th century. Over the centuries, Palazzo d’Usini has undergone many changes that, in addition to the addition of the third floor dating back to the eighteenth century, have also affected the side openings to the large portal. The facade has a portal with architraves that include the dedicatory inscription and the series of the same shape, although different in size, characterized by rusticated and diamond-pointed exhibitions. On the architrave there is an engraving showing the year of construction, while on the sides of the portal are visible the two coats of arms of the noble Manca family, a shield on which stands an armed arm. Once past the portal you can access the vaulted entrance hall on which the round arches open. The palace was acquired by the Municipal Administration in 1861 and became the seat of the Municipal House of the Piedmontese government in the city from 1879 to 1900. Later it housed the Prefecture, a school and municipal offices. It is currently the seat of the Municipal Library.