When the door opens, it sweeps a certain amount of space, which must be left clear. For example,horizontally folding doors require clear space inside and outside the door opening. Swinging doors require a large clear path, which is one reason why they are rarely found in large sizes.The sweep area of the door reduces storage space somewhat, but this issue is usually minor. More important, it requires people to anticipate the opening of the door and to keep the space clear. By the same token, the sweep of the door is a safety issue, especially if the door has an automatic operator.If you install a door that sweeps through an area that may be occupied by people or vehicles, install a prominent placard, guide lines, guard rails, or other means to avoid danger from the door.