Almost every electrical installation in the United States today is shaped, directly or indirectly, by the National Electrical Code (NEC), a standard that dates back further than most homeowners realize.
The NEC traces back to the late 19th century, when the rapid, largely unregulated spread of electrical wiring in buildings led to a rise in fires. Insurance, fire safety, and electrical industry groups worked together to develop a unified safety standard, which the National Fire Protection Association (NFPA) has published and updated ever since.
The NEC is revised on a regular cycle, adding requirements as new technology and lessons from field incidents accumulate. Arc-fault protection, updated GFCI requirements, and provisions for EV charging circuits are all relatively recent additions reflecting how homes have changed.
States and municipalities adopt NEC editions on their own timelines, which is part of why permit requirements and inspection standards can vary by location even for similar work. Our licensed local electricians stay current on which edition applies in Riverside CA, Longview TX, Lawrence MA, and Wichita KS.
Further reading: National Electrical Code (Wikipedia) · NFPA 70 overview