California - Attached ADU and JADU - Is it possible?

[Peter A Spears]

Hello everyone,

I've waded through hundreds of posts on ADU and JADU requirements. I haven't been able to figure out one aspect though. In my scenario I have a 490sqft attached 2-car garage. This could be converted to a living space as an ADU or JADU. I could also add a second story to this garage and part of the home it is attached to, yielding an additional 780sqft living space. I can't figure out if that is allowed though. It seems that I may be required to build a separate structure ADU to be eligible to convert the attached garage into a JADU. However, other interpretations seem to indicate that both an attached ADU (less than 50% of residence square feet) and an attached JADU (less than 500 square feet) are possible.

Has anyone successfully completed an attached ADU and JADU in CA under the new 1-1-20 mandates? Is it even possible or does at least one of those structure need to be detached in order to have both (I know you can also have a JADU attached to a detached ADU)?

Thank you for the wealth of experience here.

Peter