I can't imagine this would be defined by the Revised Code of Washington but I've been surprised before! 

(Business and Professions Code Section7071.6)

@Hai Lehttps://www.hud.gov/ll/code/llslcrit.cfm

Should I target zip codes?

Line 17 is the basis (5k).https://www.irs.gov/instructions/i8606/ch02.html

I'm assuming since the place is a new fit out it was required to spend money upgrading to California Building Code accessibility requirements but how far it went I'm not sure.

Also something else to consider is that the fire code requirements are more involved for a 3-family (interconnected) than a 2, so if it's not already compliant with the 3 family requirements you'd be expected to bring it up to compliance if trying to turn it into a legal 3 family.The phone # for the building department (technically "Department of Inspections and Standards") is 680-5201 and their website is providenceri.com/DIS - as with most city services, I find that I can usually get some help over the phone (sometimes with some waiting on hold), but they are most helpful in person, if that's something you're able to do.On the specifics of that particular property, one option that often comes up with weird utility setups like you describe, is to just have the owner pay utilities.

zip code?

CA Corporations Code §§ 17701.04, 17701.08, 17708.02, Revenue and Taxation Code § 17941Form LLC-5 (REV 01/2014) Application to Register a Foreign LLC.

All I have come across are property taxes and code violation fines which I factor into my offer.