Irodang is a Chinese character meaning a nine-shaped building. Its original plan was for 7 sections in the front part and 7 sections of the side parts. The additional section on the west gives this building 8 sections in the front. As for the room floor plan, Nacheukchae has ondolbang in the west, three sections of the central wooden floor, another ondolbang in the east, and toekan used as a passage in the end of the east. The bokdogak in the south leads to Norakdang through Bukhyeonggak. The front of the main wooden floor and ondolbang in the east has a toekan that has sabunhap door and pyeongjuyeol. Dongcheukchae has ondolbang in the east and another ondolbang leading to toekan, a banchim (lower furnace), and another ondolbang in the north and toekan. Except for 2 sections in the north, every room has a small wooden floor outside. There is one section of bathrooms in the third section of bukdan in the north.

As the frontal doritong of jukan, the first section of the west is 3,073mm, which is the largest and the seventh space, the last space of the east is 1,545mm, the smallest. The in-between space is 5 sections, with a size of 2,457mm - 2,468mm. As for the jukan of the seocheukmyeon, the first space of the front is 2,785mm. The remaining 6 sections are between 2,430mm to 2,465mm. Ryangtong of namcheukchae and dongcheukchae is 2 sections and that of seocheukchae and bukcheukchae, one section. The frontal toekan of yangdong of namcheukchae is 1,545mm and the back space, 3,673mm.

The corner stone is quadrate shaped and its upper part is slightly smaller than the lower. The column of pyeongju and goju is square and gabled. The corner is on an oblique angle. The column head has a dovetail joint that inserts bo and jangyeo with dori is on its top. Partially, it is a sorosujangjib that inserts soro to pyeongjuyeol.  

The main wooden floor and toekan is in a checkered pattern. The additional floor is jangmaru. However, toemaru, used as the passage to the south east side, is made of jangmaru. A checkered patterned floor is installed by inserting makjang from below, placing soldae in the teoddan site in the lower part and nailing them together. This installation method is called “eumhyeoldeopjang.”

The wall structure consists of plastered and jibyeokjangja walls. The latter is a structure in which plastered walls or meoreum are installed in the interior wall of an ondolbang. The lower part of the servant rooms cornerstone is installed with gomaki of jeondol. The area with a stepping stone at the frontal pyeongjuyeol fills the lower part of the floor gwiteul. Steel ventilation is installed beside the foundation stone. A divination sign is engraved in this ventilation.
Regarding the gagum the Chinese character for nine-shaped, nacheukchae consists of 1 goju 5 ryang, dongdeukchae, pyeong 3 ryang, seocheukchae and bukcheukcha,3 ryang. Namcheukchae hangs toeryang between the frontal pyeongju and najingoju and a girder between najingoju and the back pyeongju, with jongbu between dongjaju on the gojumeori and the girder.  
Ddeunchangbang crosses the lower part of the jongdori prop. Soro is inserted between Ddeunchangbang and Jangyeo. Dongcheukchae hangs toeryang between the exterior pyeongju and naejingoju, a girder between the naejingoju and middle pyeongju, and jongbo between the dongjaju on the gojumeori and the girder. The upper sections of goju and dongjaju have jungdori.

A rafter is hung horizontally between this jungdori. Seocheukchae and bukcheukchae have the same architectural style although the main space of bokan is different. Here the girder between the frontal and rear pyeong is crossed, and pandaegong is raised in the center of the girder and supports jongdori. 

All four exterior sides and the four middle sides of the eaves are single eaves. All the exterior and interior sides have a pent roof except the connection to bokdogak in the south east side. All exterior angle rafters are decorated by seonja and the eaves of the hoecheum section are all parallel rafters. A pent-roof is inserted onto a rectangular frame after placing the board and on galvanized metal covers the roof. Every five or six rafters, a buttress is installed and steel is installed to fillet.

As for the roof, southeast and southwest corners of namcheukchae, and northeast side corner of dongcheukchae are paljak roof where hapgak is installed. The northwest corner is ujingak roof where the tip of the angle rafter and the ridge are connected. Two valleys cut in the central hoecheomgol allow for drainage. The tip of the channel tiles is finished by waguto but for the tip of the hip of the angle rafter as well as the central and tip part among the neosae of hapgak, amksae and naerimsae are used. A chimmey is installed in the middle, west side, east side and rear, respectively. The four sides of the toemaru and toemaru in the east side have handrails. All handrails are gyonan but their height and shapes differ. By installing a folded floor in the passage to naejeong from the exit of the west kitchen among the back floor of naejeong, the small floors located in the south and north are connected.