Buying house with possible modifications without permit

[Mikhail Malamud]

Hi. I am looking to buy a house in Santa Monica. I strongly suspect that the house has modifications for which there are no permits. I asked the seller to show me the permits he has obtained but he is not the first owner. I am also going to request records from the city. Even if I have all the permits in front of me, how can I be certain I am not buying a house with un-permitted modifications. Is there an inspection I can pay city to request and they certify that the property is in compliance?