In this study, I would like to inquire about the composition of oegi(外機) on the hip and gable roof. Oegi purlin compose the basic member of framework of a hip and gable roof in both sides roof, supporting the inside end of the side rafter. However, the oegi purlin is not simply used to form hip and gable roof. The effects of using oegi purlin have the advantages of spatial. The spatial advantages are the width of the toekan(退間) increases as the oegi purlin escapes from column row and to increase the ceiling height by becoming a point of staying the ceiling. That reflect the desire to expand indoor space due to changes in worship behavior. Oegi purlin was used not only for structural needs, but also for altering in indoor space due to the changing times.

This study investigates how the spatial recognition structure is emerging through the case of rectangular plan combined with a combination of Dang-Sil(堂室) and Gong(工) shape roof, and identifies a type of architecture in the early Joseon Dynasty that has never been revealed. The conclusion of this study is as follows. First, the Dang and the Sil are connected to each other, but the architectural elements such as pillars, frame, and windows are distinguished and appear as separate buildings. Second, the distinction between Dang and Sil is evident by the difference in the number of ridges and the shape of the roof. In addition, the roof and roof framework of the independent rooms and the rooms were common in the right angled architecture where the direction and the expandability of each structure were maintained. Third, the construction of the Dang-Sil combined structure, in which two or more structure frameworks were combined with the rectangular combined flat roof structure, gradually changed into a single structure with a single ridge. Fourth, this change means that people of the early Joseon Dynasty recognized the Dang and Sil as separate architecture, but the strict sense of spatial separation has disappeared over time.

We have focused on the roof construction method of Urban Hanok in Bukchon, Seoul. The Urban Hanok, urban traditional housing type, had been evolved In modern context from 1930's to 1960's. We have confused Urban Hanok with traditional Hanok, because they have similar figures. But Urban Hanok have the characteristics as a result of the roof construction method. The purpose of this paper is to define Urban Hanok more concretely, thus we payed attention to the roof structure, specially to the comer that each roof structure meets. So we got some characteristics of the roof construction method of Urban Hanok in Bukchon. First, the roof construction methods of the roof are transformed at the corner parts, where three purlin structure and five purlin structure meet. The collision of the different roof structure has made a lot of types. Second, the roof slope of Urban Hanok is more gentle than traditional Hanok, that is caused by ornamental double eaves and awnings. Finally these characteristics are results of the compact lot size in urban neighborhood. The construction method is a inclusive word that contain materials, composition, ornament and social common sense. With the understanding on the roof construction method of Urban Hanok, we can define the identity and the value of Urban Hanok, And we can suggest the policy and the design guidelines for the reservation and rehabilitation for Urban Hanok of Bukchon, Seoul.