Often homes in and near San Jose have some sort of non-permitted modification done. Sometimes it’s a roof, a water heater replacement or even electrical changes (or improvements) done without the necessary permits and finals.
If you buy a home or have one with this situation and live in the city of San Jose, there’s a great deal of information available online via the city’s website. Today I was looking on the site for a client who wants to do an addition (and wondered what the limits and guidelines are for that) when I found this page. It’s a gem!
Also helpful on this page is info on what DOES need permits (most everything, by the way). Check it out!