I don’t get permits for upgrades, and don’t even know if they are required. I do have licensed electricians and HVAC contractors look at my work and tell me if it meets code, which I believe is sufficient for insurance purposes.
I don’t know about where you live, but in my area, that’s not really a big deal. I can pull it up online for any house in my city with nothing more then an address. If your house is 40 years old and you have a 10 year old AC, furnace, fence, deck, hot tub etc that you put in without a permit it wouldn’t take long to figure out. WRT non-permit work being done before you moved in, I’m not sure how that works. I’ve heard that the person who get’s ‘caught’ with the non-permit work is the one that get’s in trouble for it. IOW “It was like that when I got here” doesn’t fly, but I don’t know. But other things, like HVAC upgrades or things with serial numbers would be pretty easy to tell if they were done before or after you moved in.
I can see that a bigger city would have all that stuff online, heck they probably even have their own “codes”. Not my town, there is nothing in their zoning ordinances that specifically addresses the do’s and don’ts of the building code. They make some vague reference to adhering to “standard bulding codes” and they have the permits for mechanical/electrical/plumbing/building online. The inspector is a part timer, mainly checks out new construction, and the village does pay very close attention to those new building permits to make sure all zoning req’s are met.
But as far as the little remodeling jobs inside the house? I have been here 15 years and was never aware that they had those permits in the office. I recently told a neighbor about it who is planning on a bathroom renovation with the installation of a new spa or jet tub. The guy who is doing their granite work is going to install the tub, he is perfectly capable but now she is a little concerned about the electrical situation give that she doesn’t know what the code requires versus what the guy wants to do. Granite guy knows what he is doing, built a barnhouse on his property that he is soon moving into. Though the barnhouse is atill electrically connected to the mainhouse. He doesn’t plan on moving so that can of worms will remain closed. But he was very concerned about inspectors coming through and being discoverd by the township,but they got it through I don’t know how…
My husband wants a third bath (over my dead body) and wanted to do it himself on the sly. There I put my foot down, permit it or it’s not happening. Fug that anyway.