This study mainly inquired characteristics and changes of 'Chang-aelgool' through 38 cases(with 161 Ssang-chang) of annex and pavillion buildings in Yeong-nam region which are built during the Chosun dynasty. The method of inquiry included actual survey of windows along with bibliographical research, and the results are as below. First, through the discovery of the term 'Chang-aelgool' as an indication of the window-forming frame in 'YeongGeonUiGwe'(1680 A.D), it is apparent that the term 'Chang-aelgool' was widely used in Korea from the late 17th century. Second, the 'Chang-aelgool' of study objects are classified into 4 categories. Type Ⅰ and Ⅱ are comprised of mitre-joints which cover the 4 corners of 'Chang-aelgool' and mainly used in building annex and pavillion buildings during the early period of the Chosun dynasty. Type Ⅲ was widely used during the early and middle period of the Chosun dynasty and drastically dropped in number during the late period of the dynasty. Type Ⅳ is comprised of mitre-joint of the upper-half, tenon-jointing of the lower-half and widely used in annex and pavillion building during the late period of the Chosun dynasty. Third, the form of 'Chang-aelgool' has changed from rectangular form with longer width during the early period of Chosun dynasty to square form during the middle period and eventually ended up as a rectangular form with longer height during the late period of the dynasty. Fourth, it is considered that while mullion which is located in the center of 'Chang-aelgool' was mainly used around the main floored room during the early period of the Chosun dynasty, became commonly used in main floored room and 'ondol' rooms during the middle period and drastically dropped in number from then and ended up being not in use after the mid 18th century.

This study primarily aims to illuminate the characteristics of Meoreum in Korean traditional fitting system according to the respective types and its periodical changes. Using the research findings as a chronological indicator by which to estimate the construction date of the building is the secondary purpose. In this study 42 of Byeoldang and pavilion architecture remaining in Yeongnam district were examined through the field surveys and methods of documentary research. The research results are as follows. First, Meoreum, which is located below the windows or doors, provides protection against the outer wind and has the function to prevent some warm air of the room from flowing outside. Second, Meoreum was recorded as Yoeum(了音), Woneum(遠音), and Maleum(末音) in Yeong-geon-ui-gwe (營建儀軌) of Joseon period. While Yoeum(了 音) was used in Yeong-geon-ui-gwe (營建儀軌) of 1776 and 1856, Woneum(遠音) had been also used continuously since the year of 1800. The word, Maleum(末音) can be seen in Lim-won-gyeong-je-ji (林園經濟志), published in 1827. Woneum(遠音) and Maleum(末音) seem to be the Yi-du(吏讀) types of expression of Meoreum which is being extensively used now. Third, the kinds of Meoreum can be classified as TohMeoreum, TongMeoreum, TongpanMeoreum, and J janeunMeoreum. TongMeoreum and TohMeoreum were mostly used at the front part of Ondol-rooms, the backside of main floor called Daechung(大廳), and at the space between Daechung and rooms in the Pavilions and Byeoldangs(Annexes) that had been built in the early Joseon dynasty. TohMeoreum was usually used at the bottom parts of windows between Daechung and Ondol-rooms. TongpanMeoreum was mainly used in the mid-Joseon period and relatively high height was the distinctive feature of Meoreum at that time. J janeun Meoreum, used mainly in the late Joseon dynasty, has become lower and lower gradually in height since 19th century, so people could enter the room through the windows(fittings). Such changes in Meoreums types has brought about the flow of human traffic directly from Toenmaru, narrow wooden porch running along the outside of a room to Ondol-rooms.