The palace was damaged during the 1693 Sicily earthquake, resulting in further repairs and alternations. The upper floor was possibly built in 1707 by the architect Giovanni Barbara. The interior was also altered and embellished throughout the 17th and 18th centuries, with the main staircase being built in 1733 to designs of Romano Carapecchia. Due to these modifications, the building has a somewhat labyrinthine plan. The only remains of the original Castellania is a small courtyard with a Gothic groin vault cloister.