What legal rights do I have if a building inspector enter my house without my permission or a warrant and found unpermitted work?

project started with just wanting to redo kitchen floors. Hired someone to remove old kitchen tile and install new tiles.

Small project started evolving and we decided to get rid of some hallway arch’s to create more of an open space.

We then decided to redo a small bathroom. Moved the toilet and shower.

We were staying nearby while the work was being done. Received a letter in the mail with pictures taken from the city inspector of all the work being done. They even took pictures of the basement. The door must’ve been left unlocked as no one gave him permission to enter

Was fined almost 2K.. went to city hall and they confirmed the city inspector entered without permission so they waived the fine and got a permit.. But they cited a lot of electrical work that needs to be updated (old house) due new standard regulations… I would basically have to rewire the entire house

Please advice