Well, the video I saw at the link provided showed the doors opening inward. If they normally open outwards then it obviously wouldn't have any additional clearance requirement on the inside of the garage.
EDIT: I stand corrected. I went back and looked at the image (not video) I saw before. It was deceiving due to the layout but it was folding to the exterior. http://www.bifold.com/assets/slider-37.jpg
EDIT: I stand corrected. I went back and looked at the image (not video) I saw before. It was deceiving due to the layout but it was folding to the exterior. http://www.bifold.com/assets/slider-37.jpg