Designing from the question, “What bothers you the most?” Tzu-Ching Lin thought to all the infuriating times someone tried to open the door to a public bathroom he was using, often even when the stall was clearly marked as occupied.

If you’ve ever been in a bathroom in a restaurant, you know there’s nothing more disquieting than someone jiggling the doorknob while you’re, um, going.

“I’ve imagined so many scenarios of how to keep people away from the door knob, and it ended up as, ‘Why don’t I just make the door knob disappear?’” From this came the Invisible Door, a door designed with a retracting knob that sits flush with the door’s surface once it is locked from the inside, making it impossible for someone to even try and open an in-use bathroom stall. (2).gif (1).gif

Tzu-Ching designed the door so that locking it depends on pulling the knob from inside, thus retracting it and turning the door into a “wall”. “The difference between a wall and a door is door knob; no door knob, no disturbance,” says Tzu-Ching.

By making the locking action one and the same with the hiding of the doorknob, Tzu-Ching has guaranteed peace of mind for the person in the bathroom—or any room that uses the Invisible Door.