i have heard that if a remodel is more than a certain percentage of the building that all the wiring needs to be new wiring. help me find were does this comes from?
Absolutely correct. New Jersey is probably the premier example. We have an entire Rehabilitation Subcode that deals with this issue. The general rule of thumb is more that 50%. And if I read it right, it's cumulative. So don't try to rehab a building 25% at a time. When you do the third 25%, you'll have to do the whole building.