The building was erected next to the collegiate church in 1548 and altered between 1680 and 1700 by Giovanni Antonio Viscardi, architect at the court of the Bavarian electoral prince. Of noble proportions, it has a rectangular plan and is on three floors with a vaulted stairwell. Over the portal is a Gothic double lancet window from Palazzo Trivulzio in Roveredo. It acquired its present aspect following restoration work in 1948 to set up the Moesano Museum.