How does NEC define a multi-family dwelling?

The National Electrical Code (NEC) defines a multi-family dwelling specifically as a building that contains three or more dwelling units. This designation encompasses various types of residential structures, such as apartment buildings and condominiums, that provide separate living spaces for multiple households. The classification as multi-family is significant for numerous reasons, including the application of specific electrical code requirements that ensure safety and efficiency in larger residential environments.

Understanding this definition is crucial, particularly for those involved in electrical planning and installation, as it influences load calculations, service equipment sizing, and safety protocols that differ from those governing single-family homes or larger residential buildings with shared facilities. This precise definition helps ensure that the necessary standards are maintained in environments where multiple families reside, promoting reliability and safety throughout the building's electrical system.