We all want to have safe homes, but sometimes installing a safety device isn’t worth the expense and effort.

That’s what I think about arc fault circuit interrupters (AFCIs), even though my opinion might not be the prevailing one.

These electrical safety devices first appeared in the 1999 National Electric Code. They look similar to ground fault circuit interrupters (GFCIs). Both have a test button, a reset method and come in the form of circuit breakers, receptacles or stand-alone devices. There is a big difference between the two, however: GFCIs are designed to prevent people from getting electrocuted, while AFCI devices are designed to prevent fires.

In 1999, the code required AFCI protection for branch circuits containing bedroom receptacle outlets starting in 2002. Since then, AFCI requirements have been expanded many times, to the point where AFCI protection is now needed for “all 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in dwelling unit kitchens, family rooms, dining rooms, living rooms, parlors, libraries, dens, bedrooms, sunrooms, recreation rooms, closets, hallways, laundry areas, and similar rooms,” according to the National Electric Code.

AFCI protection is needed in almost every room of a new house. It’s also needed anytime new outlets are installed. I expect the requirements for AFCI devices to keep expanding until every outlet is AFCI protected.

Most home inspectors already recommend adding GFCI protection for the areas where people are most likely to get electrocuted, so shouldn’t we also start recommending AFCI protection for the majority of the 120-volt branch circuits within a home?

I say no.

Safety is essential, but the benefits of installing AFCIs throughout your house need to outweigh the costs. I have no problem advising my clients to add GFCIs, because they deliver a large degree of safety at a small price, usually $10 to $15 per outlet. Installing a GFCI is what I consider to be a good “starter” project for a DIY electrician.

I never recommend installing a sprinkler system in an existing home, because the cost outweighs the benefit. I say the same thing about AFCIs: They just don’t offer enough added safety to justify the cost.

Adding AFCI protection for an entire branch circuit typically requires the installation of a AFCI circuit breaker. These circuit breakers cost about $30 to $50 each. Installing them means replacing existing circuit breakers, which isn’t an easy DIY project. Additionally, many older electrical panels will not accommodate AFCI circuit breakers, and multi-wire circuits present additional challenges.

So if you have a home that was built before 2002, I don’t recommend installing AFCIs.

But I go even further: I also don’t recommend updating the AFCIs already in homes built or remodeled between 2002 and 2008.

These older AFCIs are capable of detecting only parallel arcs, which are uncommon. Newer generations of AFCI devices, called “combination” AFCIs, are far more effective at preventing fires.

Again, it comes down to cost vs benefit.


Reuben Saltzman’s blog, the Home Inspector, appears at http://strib.mn/homeinspector. He is a home inspector for Twin Cities-based Structure Tech.