All exterior, lounge, hall, stair and room doors are fire doors - meaning doors that are specially constructed to slow the spread of fire and smoke. It is for this reason that fire doors, especially in corridors and in stairways, must be kept closed and should never be propped open. If you leave a fire door propped open, you give fire a free path into the rest of the building. You may push a fire door to a position in which is stays open if the door has a magnet that keeps it in the open position; this magnet will release and allow the door to close if the fire alarm activates.