Re: Keeping (upgrading) to (current) code - when does it apply?
It may depend on whether the improvements bring to light a safety hazard. We ran into that when we changed the name on the electric account in my wife's old house. The electric department saw something they didn't like and called the building inspector who found "a safety hazard" in the electric coming into the house. Even though the line had been like that for over 40 years they required us to run a new line and put in a new panel for over $2,000. Legal, who knows, but they threatened fines and to shut off the electric until we complied. On a plus side, they didn't make us rewire the whole house.