Yes, we know that there are lots of nifty articles on the web about how to make an unobtrusive wall opening and fish an electric cord through the wall. But you probably already suspect that it is unsafe, and you’re right.

Here’s what it says in the National Electrical Code, at NEC 400.12:

Uses Not Permitted. Unless specifically permitted in 400.10, flexible cables, flexible cord sets, and power supply cords shall not be used for the following:
(1) As a substitute for fixed wiring of a structure
(2) Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors
(3) Where run through doorways, windows, or similar openings. 

   Luckily, there are code-approved installation kits for running power up inside a wall that do not require and electrician. See our blog post Why does running a power cord behind the wall for a wall-mounted TV violate the electrical code? for more on this. 

    The code allows somewhat of an exception at NEC 422.16 for power supply cords (flexible cords that are hard-wired to an appliance at one end and have a plug at the other end) connected to a dishwasher, waste disposal, trash compactor, range hood, wall-mounted oven, or countertop cooking appliance. Cords are allowed to connect to a receptacle in a "space adjacent to the space occupied by the appliance.” So a cord can go through a cabinet compartment (not a wall), but the receptacle must be accessible and located to protect against physical damage to the cord.

    Also, we suggest reading How can extension cords become dangerous?

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Here’s links to a collection of our other blog posts about ELECTRICAL WIRING:

• Which house appliances need a dedicated electrical circuit?

• Can a short circuit cause a high electric bill?

• What is the maximum spacing requirement for securing NM-cable (nonmetallic-sheathed cable)?

• Is it alright to just put wire nuts on the end of unused or abandoned NM-cable or wiring?

• What causes copper wires to turn green or black in an electric panel?  

• What are typical aluminum service entrance wire/cable sizes for the electrical service to a house?

• Why is it unsafe to bond neutral and ground wiring at subpanels?

• Should I get a lightning rod system to protect my house?

• Why is a strain relief clamp necessary for the cord connection to some electric appliances?  

• Does a wire nut connection need to be wrapped with electrical tape?

• What is the minimum clearance of overhead electric service drop wires above a house roof?

• What are the requirements for NM-cables entering an electric panel box?

• What is the color code for NM cable (Romex®) sheathing?

• Why is undersize electric wiring in a house dangerous? 

• What causes flickering or blinking lights in a house?

• Why are old electrical components not always "grandfathered" as acceptable by home inspectors?

• How can I find out the size of the electric service to a house?

• What could cause an extremely high electric bill?

• Can old electrical wiring go bad inside a wall? 

• What is an open electrical splice?

• What are the most common electrical defects found in a home inspection? 

• What is the life expectancy of electrical wiring in a house? 

• What is an "open junction box"? 

• How dangerous is old electrical wiring? 

• What is a ground wire? 

• I heard that aluminum wiring is bad. How do you check for aluminum wiring? 

• What is "knob and tube" wiring? 

   Visit our ELECTRICAL page for other related blog posts on this subject, or go to the INDEX for a complete listing of all our articles.