I agree with Tom. The installation will be per the latest Code, and probably justifiable in a courtroom, where most of don't want to be. The problem with such an installation will be with the AHJ. He has to enforce the former Code. The new installation by the newer Code may be viewed as a violation. And how do you argue your case to the AHJ? do you in fact take him to court? and on what premise?
I am not familiar with NY or Chicago codes, but my guess is that they are more stringent than the NEC. The NEC gives us only a minimum safety for the use of electricity. It does not provide for the most efficient use of electricity, the one thing I wish it would include.
