"Switches down must be off"
What a nice idea. Oddly enough, it hasn't been "part of code" for all that long ... maybe 20 years. Even then, the rule applies to DISCONNECT switches.
While an ordinary light switch may serve as a disconnecting means, 3-way and 4-way switches cannot. There are two reasons why they cannot qualify as disconnecting means.
The first is that it's simply too easy for you to turn things off at one switch ... while someone around the corner flips the other switch "on."
The second comes from violating a much older (maybe 40 yr. old) code rule: switching the neutral.
While no longer allowed by code, I still encounter 3-way switches that are arranged in a manner that switches the neutral. This method can present a situation where the light is 'off' only because both wires -the 'hot' as well as the 'neutral'- are hot.
Others have advocated motion sensors. Another nice idea, but limited. Fluorescent lighting ... so fondly thought of by the energy code wonks ... don't like motion sensor switching. The bulbs don't reach full brightness, the ballasts' electronics have issues with the sensors' electronics, etc.
Think of it as conflicting codes - or good intentions run amok.
Then there are unintended consequences; my cat trips every motion sensor on the street as he walks by. Just think how much fun that might be in your house at night.
