I'm curious about how the local AHJ will be able to properly enforce this code.
If a couple with grown children decide to convert one of their three bedrooms into a den or office will the inspector approve of not having an arc fault in the office? Now let's say he does and a year later the couple put the house up for sale and still list it as a three family do they have to upgrade that "office"? If it got missed during the house inspection during the sale and three months later one of the new owners got electrocuted in the old "office" who would be liable?
That's a good point. I'm more curious to see what kind of problems develop with nuisance tripping of the AFCI. It is designed to open when arcing can cause a fire and is supposed to be able to tell the difference between a "good" arc (switch turning on) and a "bad" (dangerous) arc . We'll see ...
'66, They probably only mention bedrooms as a minimum. I'm guessing that it's because they want to give you a little more protection in the place where you are sleeping. By the time a smoke alarm goes off it may be too late to get out of the room.