Regulations for adding a unit or househecking?

[Sooyeon Kwon]

Hello,

i live in OC and am looking into purchasing a property to househeck, specifically by building a small separate unit in the backyard. In terms or regulations for doing so, do I need to check with HOA? Or the city? What are some things that I need to look out for when trying to househeck?
also, how much should I look into if I were to build a studio with a small kitchen and bathroom in the unit?

Any suggestion/feedback would be appreciated.