🏘️Real Estate Basics
AFCI (Arc-Fault Circuit Interrupter)
Definition
Electrical safety device required in modern construction that detects dangerous electrical arcs (sparks from loose wires) and shuts off power before fires start. Standard in new homes since 2002; critical upgrade for historic homes with aging wiring.
Example
When rewiring a 1920s Winchester home, modern 200-amp service with AFCI breakers costs $18,000-$30,000 but dramatically reduces fire risk compared to original knob-and-tube wiring.