I'd appreciate insights on the requirement to provide emergency / standby power to elevators during a power outage.

I understand that as per most building codes, for a building classified as a "high" building such as building 6 storeys and over, there is a requirement to provide at least one or all elevators on emergency / standby power. Would this be true or at least one (1) elevator is required to be on emegency / standby power?

What would be the requirment to provide emergency / standby power for elevator in buildings not classifed as "high" buildings i.e. buildings less than 6 storeys?

Thank you.