While the Nijo-jo Castle aimed at the completion of pure Shoin-zukuri, the Shoin in the Katsura Imperial Villa was considered to aim at Sukiya-gamae (also called "sukiya-zukuri" (building in the style of a tea-ceremony house)) instead of pure Shoin-zukuri.
二条城が、純粋な書院造の大成をめざしたのに対し、桂離宮の書院は、純粋の書院造りではなく、数寄屋構えをめざしたと考えられる。