 There are three rooms on each side of the central corridor, with the exception of the area set aside for the nautilus-chambered double elliptical staircase which rises three floors.The floor plan is based on #17/18 of the 20 permutations within the Palladian grammar by Andrea Palladio, an influential 16th-century Italian architect.At each end of the central corridor on the main floor are front and rear entrances with cut-glass transom and side lights.