The palace has the form of an 18th century, neo-renaissance Italian villa. Hence the supposition, unfortunately not supported by any documents, that it was designed by Franciszek Maria Lanci.
The Orońsko palace was erected opposite the old, wooden manor with a rectangular base. To the one-storey main body, partially with a basement, gradually new projections were added, as well as another storey and two four-sided towers – one from the east and the other from the west. There are two kinds of windows built in the house: casement windows framed by a stone jamb and a cornice, and more representative French windows porte-fenêtre, which reached the floor, framed with pillars and topped with an arch. The main entrance to the Palace is situated centrally in the north elevation and has the form of a niche with a conch, coffer ceiling, flanked with a pair of pillars. On top of them there are two allegorical women figures with a sheaf of corn and a wreath of flowers. The door enclosed in a pair of pillars is crowned with a lintel bearing Christiani’s coat of arms ‘Jarosław’. The remaining architectural and sculptural details can be found in the north corner projections and in the south elevation. It is a group of six busts of mythological figures, placed in round, shallow niches highlighted by stone jambs. In the east there is terrace, built by Brandt, with an entrance into the garden, distinguished by a decorative portal with a pair of caryatids bearing an extensive entablature of the lintel and a cast iron balcony of the east tower. The walls of the tower are decorated with Corinthian pillars, the lintel topped with an attic and arch windows or blind windows. The south projection, housing the drawing – room, is topped with a triangular gable with a relieved, stylized ornament with a monogram AC (Amelia Christiani). Next, there is another, smaller terrace with stairs leading into the garden. In Brandt’s times, to the west side an octagonal projection was added with an entrance porch and stairs, the attic and a quadrilateral west tower.
The Palace en suite rooms are arranged as a double-track. The corridor from the hall to the western part separates the interior into the northern and the southern tracks. The east part of the building has been made accessible to visitors, and the west part houses office and administration rooms.
Due to the historical turmoil in Poland almost nothing from the original furnishing and fittings has survived. Two fireplaces make an exception – one of marble and the other of cast-iron, thanks to solid production and their consolidation in the base they did not surrender to plunderers. The present furnishing of the manor is a creative attempt at a reconstruction of the old interior decoration, referring to the character of the epoch and the original purpose of the palace rooms. The interior decoration was designed by Tamara Książek, who for many years was the manager and curator of the Museum of Contemporary Sculpture collection.