Door locks for all unit doors (places people live) are all battery based with a fail over of being locked but only to the outside. If you're inside they all open like normal doors. It's extremely obvious months a head of time when the battery is dying and nearly all systems will report this to whatever the unlock system is.The exact system determines if you're simply turning a door handle or switching a dead bolt to leave. There's no possibility of someone sneaking in or you being locked in.
Common doors, like to a lobby or a gym can possibly fail to let you inside if there is a power failure but you will never be trapped inside. Those systems are almost always paired with a FOB so you aren't locked out and often times there's a guarantee of a property manager that is on call for emergencies.
Common doors, like to a lobby or a gym can possibly fail to let you inside if there is a power failure but you will never be trapped inside. Those systems are almost always paired with a FOB so you aren't locked out and often times there's a guarantee of a property manager that is on call for emergencies.