Before the 15th century, the main buildings of the residences of the ruling class in Seoul consisted of Momchae(身梗), Seocheong(西廳), and Naeru(內樓)‧Chimru(寢樓). Based on the equality of the relationship between husband and wife, the couple lived in the main building[Momchae] in the center of the mansion, but based on the individuality of the relationship between husband and wife, each had an area consisting of the same section within the building. Naeru‧Chimru was the two floors bedroom building became a common living space for the minister and wife, upstairs in summer, downstairs in winter. In preparation for large gatherings and important receptions, an open-structured West Hall(西廳) was located on the west side of the mansion. Momchae, Seocheong, and Naeru‧Chimru were the common building types and layouts of the residences of the highest ruling class, including high-ranking officials, until the reign of King Sejong. However, from around the time of King Seongjong, Seocheong and Chimru came to be regarded as privileged and luxurious buildings only allowed for the grand prince's residence. The layout of the bedroom, main building (including Wings), Outer Sarang[外舍廊], and Joyangru[朝陽樓] of Prince Bongrim's mansion built in the first half of the 17th century clearly shows the transitional period when the arrangement of chimru, main building, and western office was disrupted and the layout changed to the Inner main building(Anchae for wife) and Outer main building(Sarangchae for husband).