Engineered suspended garage slab

[Tundara Homes]

I have a question about spec'ing a room below a garage. I realize the garage floor needs to be engineered, and it will be after my design process is complete, but just for interest sake, what might this look like? We are designing a 22 x 24 garage with a music studio below. I have no idea what a floor like that would look like, or even how show it on the plan. I will have a lot of notes and vagueness in this area and divert design to an engineer, but I would like to at least be close.

If it was just spanned with concrete, how thick would the concrete be. If anyone has any ideas regarding this, and they would like to help, please do. Thanks.