Basic Electrical Codes

This article describes some of the more common electric codes questions.

Most electric codes for outlets are found in the International Residential Code, IRC section 3901, 3902 and 4002 and the 08 National Electric Code, NEC section 210

Most lighting electric codes are found in the 2009 IRC 3903, 4001, 4003 and 4004 and 08 NEC sections

Most appliance electric codes are found in 2009 IRC T4101, 3702 and 3905 and the 08 NEC 314, 422, 424 and 440

GFCI Required Locations

• GFCI stands for ground-fault circuit interrupter. Both electric codes require GFCI circuits in bathrooms, garages, crawl spaces, unfinished basements, kitchens, wet bars with sinks, outdoors, outbuildings.

GFCI Outlets In The Kitchen

Countertop Outlets: To protect people working in the kitchen with appliances around water section 210.52(B) of the National Electric Code requires all countertop outlets to be ground-fault circuit interrupter (GFCI) protected.

Sink Receptacle: A receptacle must be within 2 feet of the end of the sink.

Receptacle Countertop Seperation: The maximum distance between receptacles over the counter tops is 4 feet, this is measured along the wall not the front of the counter.

Circuits Required In Kitchen: The kitchen, dining room and pantry are required to have a minimum of 2 20-ampere circuits. see our article on Wiring a GFCI Outlet for more information.

Dedicated Circuits: The two kitchen GFCI circuits are each dedicated, meaning that they cannot supply power to anything else except the kitchen outlets.

Kitchen Island: If you have an island it needs to have a outlet on it. If it is large it will need a GFCI at each end but electric codes only require one. [09 IRC 3901.4.2&3]

Countertop Outlet Height: Counter top receptacles can be no more than 20 inches above the counter top [09 IRC 3901.4.5]

GFCI Outlets In The Bathroom

Bathrooms and Outlets: Bathrooms must have GFCI protection. [IRC E3902.1]

GFCI In Bathroom Connected to Other Areas: The bathroom circuit shall be a minimum of 20-ampers and can only supply the bathroom outlets. It can supply multiple bathrooms. Exception: If the 20-amper circuit supplies a single bathroom then other equipment in the same bathroom can be powered by the circuit. [IRC3603.4].

Sink Receptacle: A receptacle is required within 3' of the sink [09 IRC 3901.6]

Receptacles and Showers or Tubs: No receptacles are allowed directly over or inside the shower or tub space [09 IRC 4002.11]

Wiring Support and Protection

Nail plates are required if there is less than 1 1/4 of wood between the cable and the face of the framing.

Cables must be supported within 8 inches of a plastic electric box (with a cable staple) NEC article 314.17(C)

Cables must be supported at least every 4'-6" by a framing member or other support.

Lots of sheds have refrigerators. The refrigerator must be on a circuit other than the GFCI circuits. Even if you are not planning on having the electrical inspected it is wise to put it on its own dedicated 15 amp circuit so that it can't be tripped by something else and spoil the food.

Hallways and Habitable Rooms

If your storage shed is a habitable space then it will need to comply with current building codes.

Any wall that is longer than 2' in a bedroom needs to have a receptacle. [09 IRC 3901.2.2]

No point on a wall should be farther from a receptacle than 6 feet horizontal (the idea is that the receptacle serves an area 6 feet on each side of the receptacle). This generally means that there shoud be a receptacle every 12 feet or less. The horizontal measurement is along the wall surface, you can't cut corners.

There should be a receptacle within 6 feet of a door.

Switched receptacles must be half hot to be included in the "within 6 foot of a receptacle" rule.

Hallways that are longer than 10 feet must have a receptacle.

Any unfinished room or area of the basement must have a GFCI protected receptacle.

Smoke alarms are required in sleeping rooms and adjacent areas. Most sheds are detached from the house so the smoke detector will not need to be wired in series with the smoke alarms in the house.

Smoke alarms need to be wired in series so the activation of one sets the others off.

Smoke alarms must have electric power from the building and a battery back up if the power goes off.

Basements and garages must have one general outlet in addition to outlets installed for a specific use for something like a clothes washer or freezer. [09 IRC 3901.9

Every part of a basement that is unfinished must have a receptacle [09 IRC 3901.9]