If you're doing a bathroom remodel that includes new electrical wiring, you should be aware of bathroom electrical code revisions that have been adopted over the years by the National Electrical Code (NEC). Besides these revisions, there may be additional new local codes to which you must adhere if you want to pass inspection. Most bathroom electrical code requirements have been in place for some time now and aren't particularly surprising, but if the bathroom hasn't been updated for 20 or 30 years, it will require some new circuit wiring on your part, and you may need an electrician.
Bathroom Electrical Code Requires AFCI and GFCI Protection
Ground fault circuit interrupters (GFCIs) have long been required in bathrooms, but since 2014, the NEC has required arc-fault circuit interrupter (AFCI) protection in every lighting and outlet branch circuit in the house, which includes the bathroom. You don't have to retrofit existing outlets unless you're doing new construction, which is basically any electrical work for which you need a permit.
You can satisfy the bathroom electrical code by installing combination AFCI/GFCI outlets, which are available everywhere and look just like standard GFCI outlets, but the preferred method is to protect entire circuits by installing AFCI/GFCI breakers in the panel. Installing a breaker gives you more flexibility in placing your bathroom outlets because unlike standard outlets, which you can use if the entire circuit is protected, AFCI/GFCI outlets must be accessible, so you can't put one in an out-of-the-way location where it might be convenient to have one.
The Bathroom Needs at Least Two Dedicated Circuits
Many people live in homes built during the construction boom of the 1950s and '60s, and in those days, it was permissible to extend a branch circuit from another room, such as a bedroom, into the bathroom. This is no more. The bathroom electrical code now stipulates that the bathroom must have dedicated circuits that aren't shared with outlets or lights in any other room.
You must provide at least two of these circuits. One is a 20-amp circuit that powers the outlets, and the other is a 15-amp circuit for the lights. If the bathroom has a ventilation fan, it can occupy the lighting circuit, but the circuit should be upgraded to 20 amps. An amenity with a large power draw, such as a Jacuzzi, should be on a separate circuit.
According to Electrical Construction & Maintenance, the bathroom electrical code doesn't specify that the dedicated outlet circuit should serve only one bathroom. Multiple bathrooms are allowed as long as the circuit has only bathroom outlets and does not power lights or outlets in other rooms.
Spacing and Placing Bathroom Outlets
At a bare minimum, you must have one electrical outlet in the bathroom, but you'll probably want more than that. The NEC now requires all new electrical outlets in a dwelling unit to be tamper-resistant, including the bathroom outlets. The National Fire Protection Association, which publishes the NEC, frowns on extension cords, especially in the bathroom, so outlets should be spaced so there is always one within reach of a 6-foot power cord, which means spacing them a maximum of 12 feet apart.
In addition, you can't place an outlet any closer to the bathroom sink than 1 foot. If you expect the bathroom to be used by people with disabilities, then the receptacles behind the countertop should be no more than 44 to 48 inches from the floor depending on the width of the countertop. Otherwise, there are no height restrictions. Bathroom receptacles can't be placed directly over the sink, bathtub or shower.
Bathroom Lighting Requirements
The NEC requires at least one overhead light in the bathroom, and this can be part of the ceiling fan. That's a bare minimum, and you'll probably want to provide more lights, such as vanity lights, wall sconces or extra ceiling fixtures for convenience and safety. There's no restriction other than to provide waterproof fixtures in the shower.
The best place for the light switch is on the wall next to the entry door, and it should be inside the bathroom to prevent someone from turning it off from outside and leaving the bathroom occupant in the dark. Switches are forbidden inside tub and shower enclosures, and if space constraints require you to put one within reach of someone in the tub or shower, the light circuit must be protected by a GFCI breaker.
An Exhaust Fan May Be Required
Moisture in an unventilated bathroom can corrode wiring and fixtures and create a fire hazard, so the NEC requires either a window that provides at least 1.5 square feet of open space or an exhaust fan, and some local authorities require both. The fan can be part of the overhead light, and it can be placed anywhere, but it must be waterproof if it's over the shower. The NEC doesn't require the fan to have GFCI protection.
Chris Deziel is a contractor, builder and general fix-it pro who has been active in the construction trades for 40 years. He has degrees in science and humanities and years of teaching experience. An avid craftsman and musician, Deziel began writing on home improvement topics in 2010. He worked as an expert consultant with eHow Now and Pro Referral -- a Home Depot site. A DIYer by nature, Deziel regularly shares tips and tricks for a better home and garden at Hunker.com.