How To Build Airlocks

Build two doors
Any two doors can be linked to form an airlock.




 * Build two doors, one or two tiles apart.
 * Click on one of the doors and click the "Link" button in the top-right of the dialog.
 * Now click on the second door to link it to the first.

Note
When two doors are linked only one can be open at any given time. If the linked door is open, characters will wait at a door until it is able to open again. You can force a linked door to close by clicking "Toggle" in the doors dialog if high traffic is keeping it open and causing jams.