Should I build a basement ADU?

[Bob Ross]

I want to finish my basement to get more living space, but also to increase the value of my home. I was thinking to make it into an ADU with a bathroom and kitchen and then either rent it out or just use the space as an extension of my house. Would have it be an official ADU make my house more valuable than simple finishing the basement and adding a bathroom, bedroom and kitchenette in the basement? Also if it's an a Adu, would be current 3 bedroom 2 bath then be considered a single family 4 bedroom three bathroom house?

thank you