Unclear on what is required in CA for "plans."

[Account Closed]

I have a home that has vaulted ceilings. The exterior wall bumps in at weird angles, but the ceiling continues in a straight line outdoors, if that makes any sense. So I want to extend the back of the house to the load bearing posts that sit outside and knock down the weird angled current exterior walls, Ceiling and flooring stay the same. 

For something like this, I've been told I need an architect to draw plans. I've also been told that, no, a drafter will do. I've also heard that people just use software and draw the plans themselves. 

Are all of these options okay in CA? Or no? Where would you start on a project like this in this state? In my old state, we could draw up plans on a napkin and send them in, get our permits. It wasn't as particular. 

Thank you! 

-Mary