Los Angeles - Old Home How to Find Old Permits

[Jasper Li]

I am in escrow on a duplex built in the 1920's in Los Angeles. There's an additional room that looks like its either part of the garage or an addition. I've looked online for old permits but the only thing I can find is a record from when it was built. But that doesn't have any information on it. Anyone have any ideas on how I can figure out what's exactly permitted if the records are too old to tell?