Door


 * Allows passage between walls. Crucial for room navigation. - In-game description

Can be sealed (locked) to prevent citizens and invaders from passing. Doors will slow, but not stop the spread of oxygen between two rooms unless one of the two rooms has been set to "Seal Oxygen". (To do this, select the room, not the door).

Tips

 * Build your doors with an adjacent Fire Extinguisher so that citizens responding to a fire can quickly obtain one.
 * Building doors directly across from one another in a hallway allows for quick access between the rooms, but can also make it easier for enemies to traverse the station.
 * Remember to seal doors when boarded to deter enemy movement.