Mr. Brunning there is nothing in the 2008 NEC that says you must use a minimum #12 conductor. There used to be a rule that the RECI had in their RECI manual which was approved by the State that said minimum #12 conductor in commercial wiring. That is long since gone away. There is alway a possibility that the plans may be asking for #12 wire, in which case the inspector would be expecting #12 wire.