The folding door is not installed for the purpose of separating the entrance or space, but instead of the general opaque door located on the second floor.​

To make it easier and more convenient to move large quantities of materials or items from the outside into the high-rise interior, the folding door will be installed and used as a window and a wider entrance. Large quantities of materials or large items cannot be moved directly to elevators, stairs, etc., so if you use a forklift, you can easily move them through the window, which can cause inconvenience and inconvenience in moving and re-growing the windows.

Even if construction is done on a high floor, not on the first floor, it can be installed sufficiently using Sky Equipment (Sadari Car). Usually, the folding door is closed, fixed, and used as a window to view the outside view, but if necessary, the folding door can be opened and closed so that many materials and items can be moved directly from the first floor to the high floor without having to move them one by one.

As a folding door exposed to the outside, it was designed with an insulating folding door frame to prevent external environmental temperature and weather changes from entering the room. For the same reason, the frame color was also black, which is resistant to pollution. It minimizes the after-sales phenomenon by using a mold painting method rather than a powder painting method, which is used for a long time without lifting, peeling, discoloration, etc. and increasing the durability of the color.