The building codes have requirements for where a light switch must be installed, but we know of no code citation that says a light switch must be installed so that the “up” position of the toggle energizes the circuit. However, it is customary to do it that way for single-pole switches in the United States. 

    The U.K. is opposite: you normally toggle down to turn on a light switch. The issue is further complicated by 3-way light switches—the kind that, for example, are used to control the lighting for a stairs from both the top and bottom—and simply toggle from on to off, or off to on, when the switch position is changed. 

    We don’t write up a single-pole light switch that is installed with the down position as “on” in our inspection report,  but do mention it to a homebuyer for two reasons: 

1. When the switch is installed backwards from what is standard in the U.S., other than a 3-way switch, it means that a professional electrician did not do the wiring and there may be further unprofessional wiring hidden from view.
2. Once a prospective homeowner knows about it, they can choose to live with it, since it is not a safety defect, or have it reversed.  

    There are also three-way light switches that are used in pairs to control lighting from the top and bottom of stairs or opposite ends of a long hallway. The position of the switch does not indicate either on or off. Go to our blog post How does a three-way switch work? to learn more. 

    Also see our blog post How can I figure out what a mystery wall switch does?

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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?  

• 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?

• 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? 

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

• What is "knob and tube" wiring?  

• What is the code requirement for receptacle outlets in a closet?

   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.