No drawings available for property

[Jeff Cliff]

Hi,

I am in an escrow for a property requiring major fixer-upper work. The property has a lot of unpermitted additions and alterations which would need to be corrected. I checked with the city but doesn't seem the city has any existing building plans/site plans. 

This is my first fixer-upper so not quite sure where else I can check for existing building plans? If not, I may have to get CAD-drawings done by someone. If I have to go this route what all drawings should I get? I may be doing some renovation work but may or maynot use another architect for renovation/remodel work.

Thank you.