As a place where you can often see the folding door installed, you can see it installed outside, such as cafes, shops, stores, and shopping malls. Therefore, some people think that it is a window that can only be installed outside. The folding door is a type of window that can be installed and used anywhere regardless of exterior (outdoor) or interior (inside), and you can select the appropriate folding door frame and rail depending on the place of construction and purpose of use.

Folding doors installed indoors are sometimes installed as insulating folding doors, but because they are installed inside, they are most frequently installed as non-heated folding doors. This construction site was also installed with a non-linear folding door, which further increased space utilization by folding rather than a fixed wall or fix window.